In a recent post about carbon monoxide detection, we meanered off into battery charging, and Michael MacLeod asked me to repost a particular reply in a new topic. I've also added Kyle Ewing's question.
This text comes from page 2 of this link: http://c34.org/bbs/index.php/topic,4313.15.html
Quote from: Michael on May 26, 2008, 10:24:46 PM
Is it your view that the boat should generally not be plugged into shore power?
Michael, In all of our years with
Aquavite and in earlier boats [celebrating our 25th year of sailing on SF Bay this past weekend], we never left our boats plugged in, and none of 'em sank! The reason is basic: we just do not know how poorly wired our neighbors' boats may be. Stray electrical can come from a bad dock wiring design or installation [not in our marina, though] or from poorly wired other boats even to a good marina system. We intend to have the zincs continue to do their work and not spend money on a new shaft or propeller if we can help it.
That said, I've learned a lot recently from John Nixon, a frequent contributor to this Message Board. Once I [
finally] installed our Link 2000, I learned two very important things: 1) my "energy budget" done in my head for the past ten years was pretty much right spot on (see: http://c34.org/bbs/index.php/topic,3976.0.html); 2) my estimate of input TO the house bank FROM the various charging sources was NOT very good because I hadn't taken into account the acceptance rate of the batteries and the tapering off of the charging amperage even with a smart regulator and a smart three stage Freedom 15 inverter charger.
In discussions by email with John, as a result of what I term "Fridge Follies," wherein I was doing detective work on why our fridge would not restart during the second night at anchor, I learned two things: 1) equalize your batteries regularly to avoid diminished performance [assuming your batteries are wet cells and your manufacturer says it's OK to do so]; 2) John provided this:
"Leaving lead acid batteries on float charge 24/7 will reduce the useful life of the batteries by as much as 35 to 40% compared to cycle charging, which by definition is to charge them only when they need recharging, then leave them alone. The continuous float charge results in accelerated positive grid corrosion, which has the effect of turning the positive plates in the battery into mush: a soft, expanded material that produces increased internal resistance and decreased deep cycle capacity. I only use cycle charging on my boats now, but I will leave them overnight or maybe for a day or 2 with the charger on just to make sure that they get fully recharged." I noted that in order to do so, I'd start a program of plugging into shorepower to top off the batteries once I got back to the slip before I left. He added:
"I doubt that an extra 30 minutes with the charger on when you get back to the dock is going to get your batteries fully recharged: that last 5% or so takes a long time, even with the very low internal resistance of AGM batteries like I have on our boat. If you are adverse to leaving the charger on all the time when you are away from the boat ( which I support completely, but not for the reason you might think...), a good simple way to give the charger time to do its work is to put it on a cheap/inexpensive 24 hr time switch with the ON peg pulled out. Just set it to run for 24 hours when you leave the boat: manually start it with the timer set just after the OFF pin, and it will dutifully turn itself off after a good 24 hour charge. In most cases, that will generally make sure that you have reached that 100% charge that the batteries need to not begin loosing capacity due to sulfation. So, for many reasons, it's important to both keep your batteries fully charged, avoid keeping them plugged in 24/7 on float, and take care of them. I am constantly amazed at the number of plugged in boats that NEVER GET USED. Whenever the owner comes down to the boat, there are going to be a bunch of things that don't work, most importantly their electrical systems.
The fridge works much better now after the equalization, which I intend to do more regularly now that I know. The voltage used to drop to 12V whenever the fridge started running. After the equalization the voltage remains high and only slowly tapers off after fridge run time and during the off cycle of the fridge, the voltage actually rises a bit.
Live and learn.
From Kyle: Regarding partially discharged batteries and leaving the battery charger on when the boat is unattended, how do people handle leaving the boat after discharging the battery (i.e. after an overnight cruise with little motoring) then closing up the boat for the weekend?
I dislike leaving partially discharged batteries and dislike more leaving power to the boat, especially if I might be away for a week or two. I leave the charger on while unloading and closing up but know the batteries need more than an hour of charging.
Stu, thank you for starting a new thread with your post. It seemed too good to bury in our carbon monoxide/propane gas/battery gas/???? discussion.
I am a dunce when it comes to batteries and electricity. Can you help by answering some questions that arise for me on reading your post. [Later added note: Stu, on searching, I see that you have written elsewhere at this site about batteries and electrical issues. I am following up those posts now so please don't think you should write anything in answer to my questions here that you have written elsewhere. M]
You wrote: In all of our years with Aquavite and in earlier boats [celebrating our 25th year of sailing on SF Bay this past weekend], we never left our boats plugged in, and none of 'em sank! The reason is basic: we just do not know how poorly wired our neighbors' boats may be. Stray electrical can come from a bad dock wiring design or installation [not in our marina, though] or from poorly wired other boats even to a good marina system. We intend to have the zincs continue to do their work and not spend money on a new shaft or propeller if we can help it.
Question: Will you explain how having your own boat "plugged in" relates negatively (bad pun) to other boats' wiring, bad dock wiring, zincs doing their work.
You wrote: That said, I've learned a lot recently from John Nixon, a frequent contributor to this Message Board. Once I [finally] installed our Link 2000, I learned two very important things: 1) my "energy budget" done in my head for the past ten years was pretty much right spot on (see: http://c34.org/bbs/index.php/topic,3976.0.html); 2) my estimate of input TO the house bank FROM the various charging sources was NOT very good because I hadn't taken into account the acceptance rate of the batteries and the tapering off of the charging amperage even with a smart regulator and a smart three stage Freedom 15 inverter charger.
Question: are there generally just two charging sources: the [whatever it is - generator?] on the engine and the 110 volt charger?
You wrote: In discussions by email with John, as a result of what I term "Fridge Follies," wherein I was doing detective work on why our fridge would not restart during the second night at anchor, I learned two things: 1) equalize your batteries regularly to avoid diminished performance [assuming your batteries are wet cells and your manufacturer says it's OK to do so];
Comment: I would ask about equalizing wet cell batteries but will hold off until after searching this website for postings on the subject. At this point, I have no idea of how to do it. If there isn't another thread dealing with this topic, I would be interested in knowing from you here how one goes about doing it.
You wrote: 2) John provided this: "Leaving lead acid batteries on float charge 24/7 will reduce the useful life of the batteries by as much as 35 to 40% compared to cycle charging, which by definition is to charge them only when they need recharging, then leave them alone. The continuous float charge results in accelerated positive grid corrosion, which has the effect of turning the positive plates in the battery into mush: a soft, expanded material that produces increased internal resistance and decreased deep cycle capacity. I only use cycle charging on my boats now, but I will leave them overnight or maybe for a day or 2 with the charger on just to make sure that they get fully recharged."I noted that in order to do so, I'd start a program of plugging into shorepower to top off the batteries once I got back to the slip before I left. He added: "I doubt that an extra 30 minutes with the charger on when you get back to the dock is going to get your batteries fully recharged: that last 5% or so takes a long time, even with the very low internal resistance of AGM batteries like I have on our boat. If you are adverse to leaving the charger on all the time when you are away from the boat ( which I support completely, but not for the reason you might think...), a good simple way to give the charger time to do its work is to put it on a cheap/inexpensive 24 hr time switch with the ON peg pulled out. Just set it to run for 24 hours when you leave the boat: manually start it with the timer set just after the OFF pin, and it will dutifully turn itself off after a good 24 hour charge. In most cases, that will generally make sure that you have reached that 100% charge that the batteries need to not begin loosing capacity due to sulfation.
Comment: On Hali we have four owners. Different owners use the boat quite a lot...at least for short day cruises. As a practical matter, we probably are less concerned about a 35-40% reduction in service life of the batteries than we are in knowing that the batteries are charged up whenever anyone comes to the boat and in having dead simple procedures that everyone can follow (like plugging in shore power when we leave the boat). We will need to think whether there is a dead simple procedure for cycle charging that would avoid our "plug her in" policy which results in continuous float charging.
You wrote (or quoted, not sure which on this part): So, for many reasons, it's important to both keep your batteries fully charged, avoid keeping them plugged in 24/7 on float, and take care of them. I am constantly amazed at the number of plugged in boats that NEVER GET USED. Whenever the owner comes down to the boat, there are going to be a bunch of things that don't work, most importantly their electrical systems.
Question: Did John have another reason - it is not clear to me that he stated it although he seems to have hinted at it - for avoiding leaving the battery charger plugged in 24/7?
You wrote: The fridge works much better now after the equalization, which I intend to do more regularly now that I know. The voltage used to drop to 12V whenever the fridge started running. After the equalization the voltage remains high and only slowly tapers off after fridge run time and during the off cycle of the fridge, the voltage actually rises a bit.
Question: Hali has a selectable battery "tester" for each of the two house batteries, at the panel. Each gives a voltage read-out only, on an analogue meter. At what "tested" voltage would you conclude that continued use of a battery is not good for equipment aboard the boat (or that for other reasons the battery should not be used)?"
Many thanks.
Quote from: Michael on May 29, 2008, 12:03:52 AM
1. Question: Will you explain how having your own boat "plugged in" relates negatively (bad pun) to other boats' wiring, bad dock wiring, zincs doing their work.
2. Question: are there generally just two charging sources: the [whatever it is - generator?] on the engine and the 110 volt charger?
3. Comment: I would ask about equalizing wet cell batteries but will hold off until after searching this website for postings on the subject. At this point, I have no idea of how to do it. If there isn't another thread dealing with this topic, I would be interested in knowing from you here how one goes about doing it.
4. Comment: On Hali we have four owners. Different owners use the boat quite a lot...at least for short day cruises. As a practical matter, we probably are less concerned about a 35-40% reduction in service life of the batteries than we are in knowing that the batteries are charged up whenever anyone comes to the boat and in having dead simple procedures that everyone can follow (like plugging in shore power when we leave the boat). We will need to think whether there is a dead simple procedure for cycle charging that would avoid our "plug her in" policy which results in continuous float charging.
5. Question: Did John have another reason - it is not clear to me that he stated it although he seems to have hinted at it - for avoiding leaving the battery charger plugged in 24/7?
6. Question: Hali has a selectable battery "tester" for each of the two house batteries, at the panel. Each gives a voltage read-out only, on an analogue meter. At what "tested" voltage would you conclude that continued use of a battery is not good for equipment aboard the boat (or that for other reasons the battery should not be used)?"
1. Boat plugged in affecting others - This is too complicated to get into here. Suggest you read Nigel Calder's Boatowner's Manual for Mechanical & Electrical Systems, or other fine boating electrical books. Simplistically, if wiring on boats or the marina is bad, stray electrons can "roam" all over the place and eat your zincs and then your prop and shaft which are protected by said zincs.
2. Number of charging sources: Up to you - shorepower charger, alternator from engine, solar panel, wind generator. Go to www.jackrabbitmarine.com who have a good display or alternate energy systems and equipment. Read Calder's book. (10/10/11 - jackrabbit closed. Ample Power does a good discussion)
3. Battery Equalization - first thing, do a search on this MB for that word, or Google "battery equalization" and learn about it (again too long to retype) but John explained the WHY of doing it. Your (crappy, dangerous) charger doesn't have that feature.
4. Different Owners - I discussed that philosophy in the earlier long discussion about your boat. You can chose to keep it as simple as possible, and run the boat like a rental car operation. Or you can chose to educate the owners so they understand more for their safety. I would consider learning far superior. If YOU and your shipmates do NOT think that a 40% decrease in battery life is worth $$$, then, continue to pursue your way of doing things. I would definitely care about that kind of unnecessary outlay that could EASILY be completely avoided with a mere tad of judicious operational understanding. I asked before: do you have a Link or other battery monitor? If your goals are simplicity and making sure the batteries are charged, then you NEED a monitor, because up til now you've been simply guessing about the overall condition of your batteries, which is a completely different thing that assuming they're charged BECAUSE YOU SIMPLY LEFT THE YELLOW CORD PLUGGED IN ALL WEEK. Please, Michael, think about the different concepts. If they don't worry you, then - your boat, your choice.
5. Other reasons for NOT leaving plugged in - don't know, perhaps John will join the party here, could be as simple as people stealing shorepower cords for the copper these days, but given what you have to address, I would think it's small potatoes at this stage.
6. Battery "tester" - 11.8 V is a dead battery, 10.5 V everything will stop working. Analog meters are horribly poor when compared to digital. See above discussion about battery monitors. Relying on voltage alone is poor battery management. Download and read the Ample Power Primer, previously recommended in almost all of my charger thread discussions (www.amplepower.com). Also read West Marine Advisors in their catalogs' electrical section, 'specially about batteries and chargers.
A few random reasons not to stay plugged in 24/7.
I know Thunderstorms aren't the norm in B.C., but they happen. Lightning strike causing a voltage surge through the marina wiring frying the electrics on your boat.
Joe Power Boater up the dock keeps the refer, ice maker, battery charger, and heater on so his boat is dry and ready to go for the next weekend. Power overload pops the breaker, not found for several days. If you (or co-owner) left anything on your batteries are probably dead also.
Mr Murphy decides it's time for that unseen 120V power line between the shore power plug and the electrical panel to chafe through and short, the resulting fire destroys your unattended boat and those around yours.
Your neighboring dockmate or repairman or marina personnel accidentally bumps the dock cart into your dock power box/cable. The momentary disruption causes arcking inside the plug. May cause fire, eventually will result in replacement.
It's all doom and gloom. That said hundreds or thousands of boat owners do it and have no problems. It's your boat, your choice. Personally I'm in the unplug when you leave camp.
Ken, very good input. There have been many discussions about battery operation, and one in particular, "batteries and the fridge," years ago, raised many valid issues about why people keep the fridges going - I want cold beer (vs. bring a cold six pack when you drive to the boat, the fridge will cool down in short order); a want to leave my ketchup and mayonnaise and mustard onboard just alike a cabin-in-the-woods (vs. it's not that hard to get small bottles and take em with you each time); I want ice (v.s buying a small pack on the way). The list is endless.
Reason for this is twofold: one to address the "leaving it plugged in controversy," and second, to begin to address Kyle's question:
You've been out all weekend, don't want to leave your boat plugged in, KNOW that your house bank has NOT been fully charged. What do you do?
I think the answer is what John Nixon suggested to me. Saying that, we have a Freedom 15 inverter/charger combo wired directly into the incoming A.C. wiring. Using a simple timer would require cutting the incoming wires and wiring a timer in the A.C. wiring. Could be done. I'm fortunate because we live close to the boat and I can get down and unplug if I choose to leave it on one night.
I added a small solar panel. By the time I return the next week the batteries are full again.
What are others' experiences?
Stu:
Many thanks. I appreciate the time you've spent on this topic here and elsewhere.
1. I do have Calder's book...and think I have even read it once right through...but, in my brain, the study of batteries and electricity seems to fit into the same category as the study of weather: I can read about it but don't get it...and what I do learn doesn't stick. The problem may be inadequate practical experience...but that can be remedied.
2. Probably only shorepower charger and alternator from engine make sense for us with Hali.
3. Battery Equalization - I'll read about this...and, yes, I unplugged that charger this morning. Lionel and I have agreed today that we will get a better charger...which will give us something extra to investigate.
4. Different Owners - knowledge for safety. Yes. And on further thought (spurred by your concern on this point), it has struck me that we must be able to do something simple that will result in the batteries being charged in the best way without requiring that everyone understand why. Generally, I write up a "standard operating procedure", once I think I understand something, and the owners are pretty good about reading the procedures but, perhaps like me with batteries, it doesn't always stick. In the case of charging the batteries, several of us go to the boat often enough that, once we have an adequate battery monitor/charge controller, we could leave shore power disconnected (or just the battery charger off if we can live with Ken Juul's thousand natural shocks that shore power is heir to), then I - or anyone else who has read the "battery charging procedure" and wants to follow it - could run the battery charger when needed.
4a. Other than the analogue voltmeters, we have no fixed battery monitor.
5. Battery "tester" - If our analogue voltmeters were reading accurately, we were pressing the "dead battery" level occasionally with our old 4D's. I may have run the windlass with one or both batteries into that zone. I could kick myself for doing that if I did. I don't suppose its too good for the windlass motor.
Thanks again, Stu.
Michael, re battery chargers, there's NOT anything to investigate. As John Nixon mentioned in one of the referenced links on chargers, "...I cannot recommend anything BUT the Truecharge 20 or 40..." John's a professional battery-person. Isn't that enough? With your OEM (I assume) alternator and your relatively larger house bank of (2) 4Ds, I'd recommend the 40 to reduce your charging time when plugged in. You could even get a good input when plugged in for the time you spend at a fuel dock. Many stories of how and where to mount it on this board.
One other question not asked is how your four folks use the boat: marina hopping or anchor out, and if so, for extended periods of more than one or two nights? Would be helpful to know to continue to assist.
Stu, one of my buddies (obviously not yet consulted by yours truly) is an inverter/power controller designer. Every once in a while, I have heard him muttering about various of the Xantrex devices, sometimes favourably, sometimes not so favourably, so I thought I would consult him on the choice though I saw favourable references on our c34 site to the Truepower charger. Of course, I am not sure that my buddy will be approaching the question from a sailor's point of view.
You asked how our four owners use Hali. It is probably too early to say. We only acquired the boat in March, 2007. Last summer we cruised her little. Our use hasn't settled down yet. Having said that, my predilection when cruising is never to overnight at a dock, to anchor out always, and to conserve power fanatically. Typical Scottish behavior, I would say. On the other hand, most of the other owners are not power-conservationists and, I suspect, are more willing -- or even keen -- to tie up overnight when they can. There has been some expressed disbelief when I have doubted (without the benefit of a power analysis) that we can cruise for long and use the fridge full-time!
I'm probably the only one who supports the idea of leaving the boat plugged in for the sake of the charger, but here goes. A 2000 gph bilge pump consumes over 8 amps. If you had a leak that kept that pump going, a 400 AH bank would only last one day. I've got two pumps; they'd run the bank down considerably faster. I also have spoken to a tech rep at Xantrex (I have a Xantrex XC3012 charger) who claims that the charger is not always charging, and that if it does not sense a current drain, it will not cycle on for 20 days. Your charger may vary in this regard, and, of course, this is only the charger manufacturer's side of the story (which reminds me of Michael's post in the CO thread about the painter and the lion....) I have a call into a tech rep at Trojan Battery, but haven't heard back yet.
Regarding this supposed 40% reduction in battery life due to float charging (i.e., on/off charging cycle), I'm not convinced. Where's the data to support this. Sounds to me like a number pulled from a dark place. Is John's assumption that "float" is synonymous with "constant trickle"? If so, we're talking apples and sirloin. What I do believe -because every source I read confirms it- is that continued undercharging is very bad for lead acid batteries (unclear to me about Gels and AGMs). Continually operating the battery in a partial state of charge or storing the battery in a discharged state will result in a condition known as sulfation. Sulfation reduces the battery's performance and may cause premature battery failure (source: Apex Battery). I just don't know how a weekend sailor who lives 100 miles away from his boat, such as I do, can not leave the charger plugged in (and therefore the boat) after the weekend sail.
Regarding electrolysis, I check my zincs; not a problem. Regarding all of Ken's mishaps, I'm betting against Murphy (and looking for wood to knock on as I write this); they all seem like pretty far-fetched instances and outcomes, with the exception of someone tripping the dock power supply line (though it's never happened in the 12 years I've been on one particular dock, nor to me anyplace else). Even if the main power did get tripped, the 10 other stinkpot owners on my dock would re-set it in a heartbeat. They couldn't be without their big screen TVs and air conditioners for more than 10 minutes. But in this instance, what Ken is really arguing against is simply not leaving any 12v appliance on (other than the bilge pump, I assume). Good idea, but irrelevant to the issue of whether or not to remain plugged in to charge.
Okay, all you unplugged types, take aim ;)
Michael, if you did a search on "energy budget" you'd find this: http://c34.org/bbs/index.php/topic,3976.0.html See the first post and click on the PDFs file. It answers your question, and is included in Calder's very valuable book.
Jon's position is well founded and has merits, your boat, your choice. BTW, Jon, John Nixon has been a member of the C34 IA for many many years and actually is now the owner of his second C34, after a dalliance with a Stamas 44 for a while. He does know his stuff, and if he shows up here, as he often does, he may be able to answer your questions. I am sure it's not something pulled out of a hat or any other dark place. As noted in either this or an earlier thread from Michael that got moved over here (the co monitor that brought all of this up), John's position from a battery longevity point of view is that charge and disconnect (not his phrase, but go look it up in that post) is better for battery life. Battery life is among MANY of the issues facing us as skippers, and fear of sinking at the dock is certainly up there among the top ten on the list.
Speaking of lions, Ken. [No, I mean Jon! Thanks for the correction, Jon.] Or maybe Christians. You may have no limbs left when the "unpluggers" are finished with you. Having been a "plugger" for the past year, there is part of me that is heartened by your stand...it plugs for you. Officially? I am on the fence. Your vindication would only be confirmation that I was dumb lucky. All the same...good luck.
Added later: Thanks, Stu. I've looked at your power budget .pdf. I've dimly thought of doing such a power analysis for Hali. You know, the trouble with this site is it keeps suggesting really good things to do that there will never be time enough to do. On another point, for a leading "unplugger", your response to Ken was decidely temperate! Are you by any chances thinking of hopping on the fence?
Quote from: Michael on May 29, 2008, 03:36:39 PM
On another point, for a leading "unplugger", your response to Ken was decidely temperate! Are you by any chances thinking of hopping on the fence?
I think you meant me, not Ken (Ken's a member of the unplugged club). BTW, Stu is the consummate diplomat. He's always the one adding reason and the voice of sanity to idiots like me as we spout off. I wish he were running for office in November!
Guys : I do not and never have recommended staying "plugged in" especially if you are not on board. All of the reasons listed above and in my 10 to 20 previous posts on this very topic.
I believe that Lead acid batteries will tend to sulfate out when sitting at a 100% charge and never discharged.
In addition there's the threat form thunderstorms/voltage surgesfrom lighting/wear and tear on your charger etc. The constant charging ON/sensing/turn OFF of the charger wears it out for 24/7 for what ?? - a cold beer that you could have picked up at 7/11 ??
Your boat do what you want !
Jon,
I'm with you. :thumb: Or at least I was until I sold my boat...
Jon, there are at least two pluggers here. I just like my beer cold and I'm at the boat every day. It's nice to be only 3 miles from the marina... The water was 75 degrees today and air was 95 degrees... Gotta love Texas....
Cheers,
Rick
I am a plugger too, but don't keep the charger on. Our a/c has a great anti-humidity feature but the power has to remain on. On my previous boat mold and odor was a constant problem, but on this boat everything stays clean and odor free. Not an easy trick in Florida.
I know there is some risk leaving her plugged in and having one thru-hull stay open, but the liveaboards on the next slip keep an eye on her and we are there at least once a week.
Joe
Does anyone have experience with what is apparently a new Xantrex offering, the XC, which one of Hali's co-owners, in discussion with a local marine supply shop owner, has had recommended to us as an updated and "smarter" version of the Xantrex Truecharge 40 battery charger?
PRUDENT INVESTMENTS [Stu Battery System]
Michael,
I just looked at the XC chargers. The 25A model is $689 US. The 30A is $485 in the WM 2008 catalog.
I also just received a flyer from WM with the Truecharge 20+ at $300 and the 40+ at $400.
I think the question you have to ask yourself is "What do I need and do I have to spend more than what I need?"
The XC permits charging multiple banks, as does the Truechargers. It permits the mixing of battery types. Do you need to do that? Will you ever do that? The XCs include a remote OPTIONAL shunt, but YOU have to decide what you want to employ for your use for a real battery monitor. Your choices are the Link series or Xantrex's newer "gages."
I personally believe the XC is overkill, given what you describe as your electrical system. That said, if I recall correctly, you just have the two house batteries separated into two separate banks, with plans for a separate start bank.
What we did when we bought Aquavite in 1998 was to do a complete cost comparison of different systems available at the time. We KNEW we wanted an inverter because the PO had installed a microwave. I knew the size of the house bank so I could properly size a charger. I knew we would eventually upgrade our OEM alternator, and studied what I could do with single source chargers, because so many of the good chargers come with multiple outputs, but the alternator only has one (unless you do what Ron Hill did and get a dual output alternator). I priced separate chargers and inverters, combined ICs (like the Freedom 15 we bought) and various battery gages (Link 10, 20 and the Link 2000 we bought because it controls the Freedom 15). We installed a 130A combiner, overkill for our old OEM alternator, but we knew we were going to upgrade the alternator, so when we did it in 2006 we didn't need to replace the combiner (see Nov 2006 Mainsheet Tech Notes report). I've installed a shutoff switch on the combiner to avoid overcharging the start bank when long motoring sessions are required. The Freedom has a single charging output (because the same heavy wiring is used for the inverter side), so had the challenge of learning early on what single source charging means and how to deal with it, because so many people used the multiple outputs of the chargers, but then still were forced to have the alternator output go to the C post of the switch.
I strongly urge you to think ahead about what you want to do and what will best support your needs, and design a SYSTEM that will work for all of your proposed boat uses. If your boat companions like to dock (marina - hop) then a simple charger is all that you'll ever need. If you, however, like to anchor out, then you need to start thinking about combining your two 4Ds, adding a separate start bank, increasing your alternator with a new regulator and just finding a decent charger without all the bells and whistles you'll probably never need.
If it was my boat, here's what I'd do:
1. Do the separate start battery and combine the 2 4Ds
2. This will permit you to buy only a Link 10 to monitor the house bank, rather than both. Your choice to get a Link 20 if you want to monitor both banks
3. Get a Truecharge, the XC is overkill UNLESS you plan to mix battery types in the future (AGM start bank, wet cells or gels for house)
4. In order to decide how to wire your charger (i.e., multiple outputs to separate banks or single output to a PDP) think about how you have your alternator output wired. It most likely goes to the C post of the 1-2-B switch. I've discussed this many times before. Try this: http://c34.org/bbs/index.php/topic,2977.0.html. Also click on the link in one of my posts to the longer earlier thread which discusses bigger, biggest house banks (this one: http://c34.org/bbs/index.php/topic,2347.0.html). Here's another good one: http://c34.org/bbs/index.php/topic,1208.15.html
5. Consider your alternator and decide if you want to upgrade - this could come later, but will force you to think now about future wiring
You could also just jump to Item 3 and save the rest for later.
Michael, I have a Xantrex XC3012. It's just fine, but I agree with Stu's assessment. I bought the XC series because I knew I was going to install an AGM starting battery (AGM because I knew I was going to install it next to the shaft, and I didn't want to service it). So, I thought I needed to be able to charge my flooded cell house bank and my AGM from the shore charger. But then, since I wanted to be able to charge my start bank from the alternator as well, I discovered the Balmar Duo Charge which drip charges (up to 30 amps) the different chemistry start bank from the house bank. If I had to do it over again, I would go with the TrueCharge 40, since there is no reason to keep my starter battery on the charger all the time. It actually never needs any further charging other than what the alternator supplies via the house bank/Duo Charge. As Stu says, however, you gotta figure out the whole system, and then buy the components.
Stu and Jon, you two have given us Hali-ites lots to think about. Thank you for putting so much into your messages.
Nothing I say in this message [which has been further amended since first posting] is intended to suggest that I have thought my way through what you have posted, but doing so may require more reading and thinking than I can do immediately. Meanwhile, I will give a bit more "Hali-specific" information that might fill out the picture.
Currently, Hali has the two new deep cycle marine/rv wet cell 4Ds (with a 1-2-Both switch) and one (new last year) wet cell starting battery.
Every one of the new 4Ds cells were found yesterday (May 29) to be low on fluid. Interstate (the battery manufacturer) recommended that we top up the cells with distilled water and not with more sulphuric acid, so we did that. We used just over 3 liters of water over the 12 cells, with each getting about the same amount, I think. As mentioned previously, other than one cell, unfortunately we had not checked the fluid levels when we installed the new batteries on May 13. Yesterday, the electrical panel analogue voltmeters measured one of the new 4D batteries at 12 volts, but my new Fluke 117 multi-meter measured it at 13 volts. (Stu, this seems reasonable vindication of your doubt about the accuracy of analogue voltmeters!)
I don't know what kind of alternator Hali has. She is out tonight, so I can't check. (As you will have no trouble gleaning, the electrical system -- except the starting-glow plugs-fuel pump circuit that we had a long thread about last year - is not something I have much worked on since we got Hali in March, 2007.)
The Flyback 20-3 charger aboard Hali is now turned off and, I suspect, will never be turned on again. (We are beginning the "new battery charger" debate.) Hali is not plugged in today. (We are listening to the plugger-unplugger debate here with interest.)
Three of Hali's four owners live or work within five minutes drive of Hali...so we can check on her often and do, at least in summer. From May through September, one of us probably visits Hali at least every other day. From October through April, once a week might be the norm. The marina is small, without a lot of people about, so that, except in summer, we couldn't count on anyone else observing anything wrong at Hali within time to do anything about it.
One of our owners works in a stationary diesel supply business and so has access, in case of urgency, to good technical help...but this probably does not extend to system design.
As a result of having four owners to pay for things, we are not too fussed about the cost of things. As between quality and price, we would usually decide on quality. With four sets of owners, we also value up-time and not having to do a repair again soon.
One of my co-owners and I are do-it-yourselfers. The other two co-owners are not generally involved in maintenance. We only involve professionals for things we DIYers really can't do ourselves. (This doesn't mean we are qualified...just somewhat persistent, time allowing.)
On the straight TruePower 40 versus XC question, my buddy who designs power supply systems got back to me. His response (and it may be only the first in a longer dialogue) was, I think, from the system perspective without considering, as you have recommended, Stu, our specific needs and intentions for Hali, which I did not tell him about. He wrote: "The new one [XC] is better. Consider 50 amp version. You need extra temperature sensors (it comes with one you should have one per battery). There is an optional 'intelligent shunt' that will allow you to monitor usage."
Regards.
It's about time someone mentioned keeping their beer cold, especially since many use use their boat a support to keep their bbq above water.
I stay plugged in and keep my batteries from being undercharged though I don't equalize them as much as I should. What about those hi-freq pluse add-ons that are suppose to help with sulfates?
Dave, I bought one of those pulsers last year for some pretty dead batteries. My charger at the time (17 years old, can't remember the manufacturer) wasn't capable of producing an equalization charge, so I put the pulser on a single flooded-cell deep-cycle group 27 which I used as a starting battery. It didn't have any effect so far as I could tell.
Quote from: Michael on May 30, 2008, 09:11:35 PM
On the straight TruePower 40 versus XC question, my buddy who designs power supply systems got back to me. His response (and it may be only the first in a longer dialogue) was, I think, from the system perspective without considering, as you have recommended, Stu, our specific needs and intentions for Hali, which I did not tell him about. He wrote: "The new one [XC] is better. Consider 50 amp version. You need extra temperature sensors (it comes with one you should have one per battery). There is an optional 'intelligent shunt' that will allow you to monitor usage."
Michael,
As Jon mentioned, the XC is "better" but for what? If cost is no object, sure, go ahead and buy something you really do not need. Many wish they were in that position.
But what I'd like to do, in lieu of retyping what's already been published in books and written about here in great detail over the course of the last few years, is to steer you in the right direction and give you references for you to make your own decisions.
1. Charger Sizing: As far as sizing, if I recall, you said you do have Calder's Boatowner's Manual book. If it's the Second Edition, look on page 165, or find the section on Battery Chargers with the "What Size Battery Charger" sidebar. There are two basic issues: time to charge based on house bank size and charger size where "bigger is better" to reduce time, and, in my mind more importantly, the acceptance rate of the batteries. That means how much juice they can absorb based on their state of charge, which reduces dramatically as the amount of charge reaches 100%. Those of us with battery monitors (Links, etc.) can attest to that. Point being, even if you buy a 50A charger, it's not going to take much less time to fill your bank than a 40A charger, because "it takes forever" to get that last 10% into the bank. Really.
Another great reference source is West Marine's Advisors and if you don't have the 2008 catalog, or earlier ones (which I save and cut the electrical sections out to retain), you definitely should. I was on a friend's friend's boat who is planning to do the Pacific Cup Race to Hawaii this summer, and during our investigation of their electrical system I asked him if he had a WM catalog. His wife said, "Oh, so many people asked us that so we went out and got one!" I recommend you do so, and read page 390.
Finally, most all of our C34 members who are "into" electrical systems have reported great success with the Truecharge 40 both in terms of performance and capacity, with reasonably sized house banks. As WM says, there's no sense in oversizing a charger.
Case in point is our boat. We have 390 AH in our house bank. Our charger on the Freedom 15 is 75A which is way overkill and well beyond the sizing suggestions, should be more like 40 to 50 max. The reason? It came with the 1500 watt inverter. Now that I've had a few months to work with our Link, we do not get 75 A out of that charger, BECAUSE the batteries will simply NOT accept that amount of charge. We see it start out at 50 and go through the three stage charging regimen, and with a 50% depleted battery bank, usually less than 50 A.
2. Charger Selection: As mentioned, both Jon and I have noted that the features on the XC are well beyond what you would need, but only you know what you want or need. Based on where you sail I find it unnecessary to need to consider temperature sensors. If I was sailing from Puget Sound to Mexico I might, just might, consider it, but then a smart charger usually has temperature compensation built in. As I recall (but without confirming it by going on line to Xantrex) I would not be surprised if the Truecharge have cool and hot. Sure battery temperature control is a good safety feature, I have not found it necessary. Why? Because I'm almost never away from the boat when the batteries are being charged. Your boat, your choice.
So, given all that, which I'm desperately trying to keep to a minimum (those who know me say: "Yeah, right, what century???) I encourage you to apply your energies and talents from your work and home experiences to this endeavor, and work to figure out what's best for you, your companions and your boat.
Good luck should NOT enter into it, it's a PLAN that should be developed and implemented.
Dave,
Here's a link to a discussion about the battery rejuvenators: http://www.sailboatowners.com/forums/pviewall.tpl?uid=73200280089&sku=2008142071303.78&forumabr=as&fno=21
Quote from: Stu Jackson on May 31, 2008, 01:06:55 PM
2. Charger Selection: As mentioned, both Jon and I have noted that the features on the XC are well beyond what you would need, but only you know what you want or need. Based on where you sail I find it unnecessary to need to consider temperature sensors. If I was sailing from Puget Sound to Mexico I might, just might, consider it, but then a smart charger usually has temperature compensation built in. As I recall (but without confirming it by going on line to Xantrex) I would not be surprised if the Truecharge have cool and hot. Sure battery temperature control is a good safety feature, I have not found it necessary. Why? Because I'm almost never away from the boat when the batteries are being charged. Your boat, your choice.
I'm not sure I'd go on record as saying the XC is "well beyond" your needs, Michael. If you are planning on having a separate chemistry starting battery (ever) and want to charge it directly from the shorepower charger, then the XC is definitely the way to go. The Truecharge will charge multiple battery banks at different amp levels, but they must be of the same chemistry (i.e., able to take the same voltage level). Given how little charging a starter battery generally needs, I think some kind of combiner/echo-charger is the right way to handle charging the starting battery (i.e., charging off of the house bank rather than directly from the charger or alternator). In that case, the ability to charge a separate chemistry battery is irrelevant. Xantrex is pretty crafty in its charger ratings, which makes it a little difficult to compare the old Heart Truecharge (Xantrex acquired Heart a few years ago) models against its own XC series, since the TCs are in the 20 and 40 amp range and the XCs are in the 30 and 50 range. That said, the TC 40 is $322 while the XC 50 is nearly $200 more at $515 at Defender.
BTW, I originally bought the XC 50. I returned it and got the XC 30 when I discovered that the 50 would not charge a bank under 100AH. Most starter batteries, while high in CCAs, are below 100AH, so I figured I'd better be safe with the XC 30, which will charge a bank as small as 60AH. Why they engineered this product in this way, I have no idea; it seems pretty stupid to me. Of course, now that I have configured my charging system to be entirely directed to the house bank with a feed off via the Duo Charge, the XC 50's restriction would've been a moot issue. Since I'm only a weekend sailor (for now), the 30 is quite adequate. In your case, with frequent usage by multiple owners, you should probably either the TC 40 or the XC 50.
BTW, the TC does have an optional temp reader. I would strongly urge you to get this, not only for safety's sake (although that's a good enough reason), but because the charger will limit itself to the lowest reasonable output in absence of knowing the temperature of your battery. In effect, it will assume that your battery is colder than it might be, and thus it will slow down the charging process.
PS: As I was just reading the June issue of Cruising World with the article about Frank Butler (great article BTW; I didn't realize he is 80), I noticed an ad for a Truecharge2 charger. Looks just like the XC. Comes in every amperage rating from 10 to 60, so I suspect this is a merger of the two product lines. BTW, the XC (and probably the new TC2) has two other advantages over the original TC: 1) its price includes the temp sensor, which is probably a $40-$50 value; and 2) it has read-out display, which can be mounted remotely. This is an optional buy on the TC. After a quick glance at the TC2, though, I would go with this new one, if you can find it (www.xantrex.com/truecharge2).
Hi everyone! Sorry to be so late for the party! Given the late hour, I'll probably have to do this in several sessions, but I'll try to answer all the questions eventually.
First, let me say that I am a mixed-bagger: I keep ( for the last 20-ish years) AC power on the boat 24/7 to keep the beer cold, and to keep the inside temperature of the boat reasonable with my wonderful 16,000 btu of reverse cycle air-conditioning. Down here in north central Texas, the boats never leave the water, and our temperatures can change about 100 degrees F from February to August. We don't have to worry about salt induced corrosion up here, but I did the same thing while I had the Stamas 44 on the Texas gulf coast for 9 years by exercising reasonable preventative measures to prevent salt from causing potentially dangerous electrical hazards at the dock and on the boat. Having said that, the explanation for my veiled comment about not leaving the battery charger on 24/7 ( but not for the reason you might think ) is that I have no problem with AC power on all the time, but I have some technically sound reasons to not keep any kinds of deep cycle batteries on a charge 24/7.
All battery do not like having residual charge current flowing through their plates for extended periods of time. However, for our discussion here, I'll limit my comments in particular to deep cycle lead acid batteries. As Stu accurately quoted some of our direct correspondence, the problem created by continuous charge/residual current flow through lead acid batteries in positive grid corrosion. This is something that happens anyway during the charge process, but when the charge to float mode time ratio becomes mostly float mode, the grid corrosion continues to happen with no useful effect on the battery, so that the positive grid corrosion is highly accelerated. The grid corrosion produces increased internal impedance ( i.e. - reduced cranking capability ) and reduced deep cycle capacity from the loss of effectiveness of the positive plates. The relative reduction of capacity percentages I cited due to continuous charging versus cycle charging come from 2 primary sources: manufacturer's data, and my own empirical data from messing about with deep cycle batteries extensively since 2000. The primary manufacturer I have worked with is Concorde Battery, who manufactures not only the Lifeline AGM batteries, but also a complete line of aircraft and aerospace batteries in civil and military applications. The same family that owns Concorde Battery also owns Trojan Batteries, so the experience base there is pretty broad. Trojan was the premier manufacturer of submarine batteries during the diesel/electric submarine era. They are also still the leading manufacturer of golf cart batteries, among other batteries.
The stated 35 to 40% maximum reduction in useful life of a deep cycle lead acid battery due to continuous float charging was based upon Concorde's own testing and their experiences in field applications of their batteries in solar power applications ( the ultimate cycle charge environment ). My own customer experiences and the results of my own studies with the Lifeline batteries supports the stated range of useful life reduction with some reduced effect if the float voltage is temperature compensated and well regulated at the lower end of the allowable float voltage range. In the last several years, Concorde/Lifeline has reduced their recommended float voltage range from a nominal 13.4 volts to 13.2 volts, and this will further reduce the rate of positive grid deterioration in the float mode. In one of my own examples, the new AGM 4D batteries I installed on my Stamas 44 lived about 3.5 years in constant float mode at a temperature compensated 13.4 volt nominal. At the end of that time, the measured cranking power ( CCA ) and deep cycle capacity was reduced by about 20%. The next 1.5 years was spent using cycle charging, and the measured CCA and a-hr numbers were only about an additional 5% lower. I have to note that these examples are from premium grade AGM deep cycle batteries, and the results from a relatively inexpensive flooded battery would probably be significantly worse.
So, if 24/7 float charge is bad, what to do about 12 volt refrigeration ( i.e. - your Cold Machine )? The simple answer is to provide a suitable AC-to-DC power supply to run the fridge when you are at the dock, and then run it on the batteries when away from AC power. I have been doing this since 2002. There are a number of inexpensive and suitably reliable small switching power supplies out there that will do the task admirably.
One last quick comment: I like the TrueCharge + series because it has been an extremely reliable product with good features and performance at a fair price. I have never seen one fail at all in normal service in 8 years, and more importantly, never fail in a mode that produces an uncontrolled high output voltage across the batteries. This is in stark contrast to may of the other charges that were in use on boats over the same period of time. I think the TrueCharge II has excellent potential, but I want to see some in operation over time before I offer any additional opinion. I think the XC series is over-priced and touts primary features that offer little benefit in the real world.
This will have to be it for installment #1. I'll keep working down the list of questions and comments as quickly as I can.
John
Stu and Jon [and John, who has come to the party since I first posted the following], thank you for your detailed postings on this topic. I hope many other readers are making decisions about battery chargers and can benefit also from your messages. In hopes of buying some time to make a decision on a new charger and battery monitoring system, we plan to test (as suggested in a recent posting on the carbon monoxide thread) to see whether the old Flyback 20-3 can safely be used pro tem. Work has started on an energy budget, following your precedent, Stu. Nigel Calder's book, the WM catalogue, and your other suggestions for reading are next. So any decision on the new equipment is a ways off. Jon, thanks for the information about the new TrueCharger2s. I hadn't heard of them.
John,
Thanks for your insightful input on batteries and charging.
I am one of those who leaves refrigeration on all the time and have struggled with the problem of constant battery drain/recharge. I considered a switching power supply and called Adler Barbour to get their input. This was about 2-3 years ago so I don't remember the details of the conversation but the final analysis was that this is not a good idea. I hate people who ask for advice and if it is not what they wanted to hear, they ignore it...... however your post (and credentials) compels me to revisit this issue.
Can you give us a few details on the specs of the power supply you are using and how it is wired into the system?
Thanks.
John, I love your idea about direct AC to DC conversion for the fridge. I actually wanted to do that several years ago, but the distributor (Waeco) told me not to do that. I can't remember the reason (or even if they had a good, intelligible one), but the fact that you've done it and it has worked is fantastic news. I second Michael's request for any specifics you might have about the power delivery design.
Regarding the float charge controversy, I agree that a continuous charge would have a deleterious effect on the battery's grid, but Xantrex told me -and I have since confirmed- that the float stage does not equate to always on. It's actually a cycle stage that if the charger senses no difference in voltage level in the battery, will only cycle on every 21 days (this was in regard to the XC 3012). If this is true -and I normally will see the charger register 0 amps when I return to the boat after a week- then leaving the charger on should not have the impact you have described. That said, if you leave the fridge on, the charger will come on frequently if not continuously, so your direct AC solution is a great one.
EARLIER FRIDGE WIRING CONNECTION BATTERY ARRANGEMENTS
Ray Irvine had wored out a nifty solution many years ago. See Reply #16 here: http://c34.org/bbs/index.php/topic,2143.15.html
The CO discussion Michael refers to is here: http://c34.org/bbs/index.php/topic,4313.30.html (It's a long one, too.)
Quote from: Stu Jackson on June 03, 2008, 05:17:22 AM
Ray Irvine had wored out a nifty solution many years ago.
Yup, that sounds like what I was going to do, though I'm not quite sure I follow Ray's switching description. I would love, though, to avoid the dedicated battery/separate-charging set-up if possible, and it sounds like John's found a way to do that.
Jon - Regarding the new TrueCharge2 battery chargers from Xantrex, I talked with the local Battery Direct outlet in Burnaby (home also to Xantrex). They have a pre-production version of the TrueCharger2 on hand but don't know when production models of the TrueCharger2 line will be made available to them for sale. Two other Xantrex dealers here did not have them yet, and the lady at the Xantrex Outlet Store knew nothing about them. The Battery Direct fellow thought Xantrex was still working on them.
That's classic. Xantrex is advertising the new line (Truecharge2) in print, but haven't told their distribution channel about it yet.
Here we are again with installment #2, and the main topic here will be the AC-to-DC power supply usage with the Adler-Barbour Cold Machine.
First, a little background and history of the Adler-Barbour compressor. Prior to early 2000, all the compressors were fixed speed, brush commuted motors that had a very nasty current spike when the compressor started, but also were very electrically noisy while they were running. The installation manual for these units made a strong point of using big wire from the battery and the fact that you had to have a battery on the feed circuit to help "absorb" the current feedback of the motor back into the voltage source. Upon starting, the peak starting current was in the neighborhood of 17 amps for a couple of hundred milli-seconds. However, my discussions with the engineering folks back then ( pre-WAECO ) confirmed that with a reasonably "stiff" power supply ( i.e. - AC-to-DC power supply ) there was no reason that the compressor wouldn't be happy without a battery in the feed circuit. Of course, I had already tried it by then and knew that to be the case, but it made me feel better having them agree with me...... I used a 250w 12 volt nominal switching power supply with the output voltage set at about 13 volts, which meant that I had about 19 amps available. I used this from the end of 2002 with no problems on my Stamas 44, and the next owner is still using it. The power supply had a cooling fan that ran all the time, and the fan quit after about 3 years. However, since the run current of the compressor was only about 5 amps, the cooling fan wasn't really necessary anyway, and it wasn't an issue. However, the supplier of that power supply no longer carries or makes that power supply, so to duplicate what I did will require some adaptations ( at least at a reasonable price..... ).
For the post-2/2000 Cold Machines, the compressor was changed to a variable speed brushless motor in a slightly larger and more efficient compressor, the Danfoss BD50. The variable speed motor starts "softly", and the maximum start current is less than 10 amps. This means that a 150w power supply provides ample reserve to start the compressor, and really coasts along at the 4 to 5 amp run current. The motor also runs more electrically "quiet", which is a very good thing if you have other radio receivers on the boat. This is what I have now on Otra Vez.
For change-over from AC to DC power, I use a standard SPDT 30 amp automotive relay with the relay coil power by the AC power supply. The common terminal of the relay goes to the compressor, the NC contact of the relay goes to the DC feed circuit breaker, and the NO contact of the relay goes to the output of the AC power supply. If the AC power supply is powered up, the compressor runs from shore power; if not, it runs from the house battery bank. When I'm away from the boat with the charger turned off, I leave the fridge DC power turned off at the distribution panel: if shore power goes away, I don't want the batteries run down just to keep the beer and bottled water cold for a few days.......
The power supplies I have used on both the Stamas and the current C34 both came from www.mpja.com. The 150w power supply I use for the newer compressor is part number 16020 PS and costs $40.75. If you have an older compressor, you can use a pair of the same units in parallel after carefully setting the outputs to have equal voltages before tying the outputs together. If you want to pay more and have a better warranty, you can use part number 709-S150-12 from www.mouser.com at $57.96 each. I should note that the cheap units from MPJA have worked without a hick-up for 5 years and counting being turned on 24/7.
When I have the schematic diagram of the power change-over relay scanned into a suitable format, I'll post it here as well.
For installment #3, I'll summarize my comparison of the TrueCharge+, TrueCharge2, and XC series of chargers. We'll of course ignore the fact that the TrueCharge2 is currently still marketing blue sky.......
Until later.
John
Thanks John; this is really helpful, though I haven't quite followed it all yet. Can't wait to see the diagram, if you get around to it. BTW, I'm in marketing, so "marketing blue sky" is actually reality to some of us ;) In fact, those of us in marketing actually think of it as engineering or manufacturing blue sky ;-0
John - Thanks for the description. Now if I could just engineer a way to remotely close the lid and power the fridge up about four hours before I get to the boat so it would be cold when I get there. :thumb: And for the winter months, fire up the diesel heater a couple hours ahead of time......
Craig
As a follow up to Installment #2, here is the schematic ( attachment ) for the AC-DC change-over relay and power supply wiring for the AC power supply addition to your Cold Machine. After looking over my original notes on the subject, I determined that the original 250w power supply that I used with my older Cold Machine compressor ( pre-2000 vintage ) was rated as 12v/17a. I also noted that I had adjusted the output voltage up to about 13.2 volts for maximum efficiency for the compressor. The 17a current rating is a continuous rating, and this power supply easily handled the substantial starting load surge of the older compressor.
Based upon this information, there are actually 2 better options for power supply selection for the pre-2000 compressors. If you don't mind configuring a pair of units for parallel operation, you can use a pair of 100w units from www.mpja.com, part number PS1-100W-SF12 at $32.80 each. If you would rather have a single unit, use a 240W unit from www.jameco.com, part number 137649 at $106.85. This unit has a 2 year warranty and a cooling fan that only runs on demand, which in this application will be almost never.
Craig, if you add the AC power adaption to your fridge, it can be cold all the time if you have shore power available at the dock :clap. I think I'll stay away from remote diesel heater starting............
John
John - Purchase of an XC3012 for Hali is on hold pending your comparison of the Xantrex battery chargers! We are looking forward to your installment #3.
Installment #3: Xantrex charger review and associated comments.
The actual comparison tabulation is attached as a pdf file. I tried only to list the areas that could be meaningful in normal usage. There are other shared features with small technical differences, but I judged them not worthy of much discussion. All of them have various protection features for either the charger or the batteries, so there wasn't too much point in dissecting the small print.
If you scan across the product offerings, you will note that the Truecharge2 (when it ever is actually available...) is a poor substitute for the Truecharge+. If the offered price at WM holds, the Truecharge2-40 charger + BTS combo costs more than the equivalent price of it's namesake. Not only that, it offers a significant feature loss with the elimination of the 2 stage charge protocol option ( more on that later ). The only advantage that the "2" offers over the "+" is being about 5 inches shorter in length and about a half inch shorter in height. If that is not an issue, the "+" wins hands down.
After careful reading of the product information for the XC series, I can see a few things to like compared to the "+". The on board control/display panel insert is removable and can become a fully functional control / display panel, which I think is a nice improvement over the pretty dumb and way-too-big remote display-only panel offered with the "+". The XC also retains the option of either 3 or 2 stage charge protocols, with the addition of an improved float mode which, although not well described, appears to have the ability to function in a pseudo-inactive float mode after spending a reasonable amount of time in the active float mode. For the record, a full charge can only be achieved by either an active float mode charge ( constant regulated voltage at less than bulk ) for many hours, or at the absorption voltage for an extended period of time, or a charge at the absorption voltage until the actual battery charge current gets below a relatively low threshold. If the pseudo-inactive float mode works as implied, the 2 stage charge protocol becomes less important except for a few limited number of specialty cases.
The big advertising hype for the XC focuses on the ability to mix battery chemistries between the 3 banks. While this sounds good, in most practical applications is has little importance. A mix of flooded cells and AGM batteries can be done using only the AGM charge parameters. Not many people use true gel cells any more, and if they do, it's usually all gel cells because of the problems associates with single source charging from the main engine alternator. While it's true that the multiplexed or sequential charging of the 3 banks means that each battery will be presented with an optimal charge step series based upon the charge state of the particular battery bank, the down side of this scheme is that as you sit on your boat at night with the cabin lights on, there will be periodic and noticeable light intensity changes as your house bank goes from being on charge to off charge. In this scheme, only one battery bank at a time is actually under charge. [ Jon, can you comment on how noticeable this is in the real world?? ] Since on my boat my primary battery charger will be the Prosine 2.0 inverter/charger, I am pretty committed to single source charging at the dock or underway, and the equivalent of multi-source charging for my single house bank and dedicated starting battery ( all AGM ) is not a big issue.
If you spend long periods of time away from your boat, and you don't have "shore power phobia" , then the XC series offers an optimized solution to keeping all your batteries well cared for in your absence with the sequential/multiplexed charging and the pseudo-inactive float mode.
If you are only away from your boat for a less than a month at a time, either the "+" or the XC versions can keep your batteries and your boat safe in our absence. You can accomplish 90% of what the XC can do in this situation with the "+" by placing it in the 2 stage mode after you have fully charged your batteries before your departure. Any of the Xantrex chargers with the 2 stage mode available will automatically come out of the inactive state and initialize a new 2 stage recharge if any battery falls below 12.5 volts for more than 15 minutes. In addition, it will automatically initialize a new charge cycle every 21 days from the last recharge cycle, or upon a new application of AC power to the charger. Those of you who worry about your Mother Of All Bilge Pumps running for hours at a time in your absence can rest easy as long as you have shore power available.......
For those you still using flooded cells, the automatic full recharge cycle every 21 days is especially important to you if your are away from you boat for significant lengths of time. Flooded cells have one not well recognized problem associated with sitting with no charge or on a float charge for long periods of time: acid stratification. What this means is that when a flooded cell sits still for long periods of time, the acid separates into different levels within the cell based upon the specific gravity of the acid. The portion of the acid that has the highest specific gravity settles to the bottom of the cell, with decreasingly lighter acid in layers above the denser acid. If you recall basic lead acid battery chemistry, low specific gravity is associated with lower charge levels, and higher specific gravity ( within certain limits ) with higher states of charge. Once this happens, the average state of charge of the battery decreases because most of the plates are in contact with a non-optimal acid mix. This can produce a significant loss of usable capacity. The good news is that it can be easily corrected by bringing the cell voltage well above the gassing voltage ( i.e. – to the absorption voltage ) and producing lots of bubbles: the flow of the bubbles up through the cell plates causes the acid to remix and restore a homogeneous specific gravity throughout the cell. This action also replaces charge lost through internal self-discharge of the battery ( only when left off charge: it doesn't occur on float charge ), which with flooded cells can be as high as 20 to 30% of capacity per month. To make matters, the lead sulfate which forms because of self-discharge turns in the crystalline form more quickly than that which results from heavier discharge, and the crystalline form does not readily convert back into lead dioxide during normal recharging. Lead sulfate will turn into the crystalline form in about 45 to 60 days. Once your battery has lead sulfate in crystalline form, your battery has what will usually become a permanent capacity loss. This is what having your battery "all sulfated up" means. Most flooded cells need to be completely recharged every 30 to 45 days to avoid permanent sulfation.
OK: time for the BOTTOM LINE.
Truecharge 40+: Old but very good. Best feature set per amp of charge capacity. Can deliver first rate battery care in probably 90% of all applications. Has an exceptional field reliability history. Probably will get scarce once the Truecharge2 is available in large numbers. For now, Practical Sailor John gives it a "Best Buy" rating among the Xantrex selections.
Truecharge2-40: Newer than new ( not available currently ), "cute" with it's modern look and smaller size, and capable of handling most normal applications. Lack of 2 stage charge protocol makes it less able to deal with unique situations. It will likely be reliable after the bugs are worked out of it ( and there will be some.... ). I doubt that the small current steps between models will be maintained once the product is out in the real world: too many production and inventory variants, and no justification technically for less than about 2:1 steps in charging current between models. I would buy a "+" now rather than wait on this one to become available.
XC3012/XC5012: I wanted to not like this series based upon price and what I initially considered to be some gimmicky features. However, after careful study, I have to revise my opinion. Yes, it costs more per amp than a near equivalent "+" unit, but it does have some features that offer the possibility of longer battery life in a more automatic, transparent manner than other Xantrex or other brand offerings. Also, the fixed/remote control/display panel included as part of the basic package is a plus in some applications; if you already have a battery monitor system that can tell you all you want to know about your batteries ( and why wouldn't you??? ), the remote display is not a big deal. If the pseudo-inactive float mode works as indicated, that is a big factor in achieving true "plug-it-in-and-walk-away" battery care that has been unavailable in the consumer market up to now. Even though I need yet another battery charger like another hole in my head, I'm probably going to buy one just to put it through it's paces and see if it can realize the potential I think it may have. I won't say that I think you should go buy one, because I generally only do that based upon positive personal experience. You can buy one and experiment with me, or wait for my update in 6 months or so.
Well, I still have some battery and charging things on my list to pontificate about, but that will have to wait for Installment #4.
Hope this is useful.
John
John, I would say "useful" vastly understates the value of what you have written. You should write for Practical Sailor (and thus up their standards).
Regarding the light intensity change due to charging on/off input, I have not noticed this yet. I will be aboard tonight at dock, so I will check, but the only on/off cycling I will experience is between low input in float mode to zero-input in float, because my starter bank is charged via a Duo Charge, so I'm not sure I'd ever experience the change you're forecasting (i.e., the house bank is always the charge target). I can, however, report that the "pseudo inactive float mode" does indeed work as advertised. When I return to the boat after being away during the week, the charger reads 0 amps charging. It stays that way while I'm using minor amounts of electricity (stereo, occasional water pump, etc.) For me, the combination of this no-fuss approach, along with the battery temp sensor (one supplied), and the digital read-out are worth the price. If I ever get an electric windlass, I may also use it to directly charge what will surely be a separate AGM battery (versus my flooded house bank). That said, I thought I would do the same with my current AGM starter battery, but I went with the Duo Charge method instead, and I may do that with a dedicated windlass battery as well.
Thanks again for doing this. It's truly the most superb and educational product comparison I've ever read.
Thanks for the editorial endorsement, Jon. Your check is in the mail...... :wink:
You are correct about the lack of any "flickering" if you only have one battery connected to the XC. Under those conditions it would have "disqualified" the other 2 banks and would skip them in the sequential bank charge cycle, leaving only 1 battery in the "loop". You would never see any intensity change for all practical purposes under those conditions.
Thanks for the info.
John
The COMPLETE Charger Evaluation is here: http://c34.org/bbs/index.php/topic,4352.0.html