Yes Stu, once this is done, I'll add to wiki. BUT FIRST, a question. I obtained a 20 watt solar panel -- don't ask any questions..... My question is, with a 20w output and the appropriate power box, how quickly should this charge a series 27 AGM 2 battery bank?
This kinda comes from: http://c34.org/bbs/index.php/topic,4929.0.html [Ed. - Stu]
It depends only on how discharged the battery is. At 20W your panel is putting out about 1.5amps. So if you have used 15 amp-hours it will take about 10 hours to put it back.
Lance, the question begs the answer, because "it all depends" on how depleted the battery is when you start.
If you check the WM catalog under solar, there are any number of convenient conversion factors between watts and amps and hours of output that will determine how many AMPS for how many HOURS you can replenish from any given solar panel.
But, and this is a BIG but, because of battery acceptance (see: http://c34.org/bbs/index.php/topic,4787.0.html) it'll take WAY longer than the amps input times the time used to fully charge the battery because it "accepts" less, regardless of the input, as the bank gets fuller.
Actually the #1 bank was down to 10 volts and #2 was at 11. WOW, I just acquired a second 20 w & controler for use on the other bank. Gotta love this job!
OK, I'll try this technique with you again :D :D :D
STOP! :D :D :D
Please read the Ample Power Primer, here: http://www.amplepower.com/technical_documents/index.html
There's a discussion of what to do with seriously discharged batteries. Give it a try. Manage, Test & Troubleshoot. Download the whole package.
Lance : Over the years I've noted that the solar panels aren't a straight math equation of 1.5amps per hour as they are charging @ 15 volts !!
We'll let the electricians on this Message Board decipher that for us and give them something to chew on.
A thought. Ron
Last season I began using a 22.5 watt 15 volt solar panel. In fact I used it under a palstic tarp over the the winter to trickle charge the batteries (2 paralleled banks of 2 six volts in series. Additionally I charged through a regulator. This system kept my batteries nearly fully charged at (between 12.75 and 13) volts all winter. In the summer sun of course the panel is more efficient. I think you will find that your panel is much more effective keeping your batteries "topped off" than charging your deeply discharged batteries. If you can follow Stu's (and others) advice and find a good source on bringing back deeply discharged batteries you will be better off. I have followed the advice in Calder's book dealing with boat systems (I forget the exact title) and have been pleased.
My issue was that my battery charger died and allowed my batteries to bleed down (I keep my fridge on). One bank is near 12 and the other dropped to 10. So, I have a one time issue of recharging. I have a backup batter charger I'll take out tonight. I was wondering if that one panel would recharge the low bank for the 2days I've been away. After I replace the charger, the solar will be for keeping stuff up while on the hook and not running the engine.
Let's perhaps help you organize this process.
1. What kind of "backup" charger do you have? If it's a cheap automotive charger, you could well destroy what may be left of your dead batteries. The Ample Power Primer and Calder's suggest how to attempt to retrieve dead batteries. I wold expend primary efforts to repair or find the fix for your TrueCharge charger before anything else, especially if it may be a simple thing like the fuse. That's why I linked your two messages this morning. You may have a one time job of recharging, but it should be done right, or else you'll end up with two useless piles of lead and plastic.
2. Do an Energy Budget (see: http://c34.org/bbs/index.php/topic,3976.0.html). Given you solar panel output into your house bank, you may/will see that there's NO WAY a small solar panel will ever keep up with the draw of the fridge, which, when ON all the time uses 60AH per day. Please, "do the math."
3. You noted: "the solar will be for keeping stuff up while on the hook and not running the engine..." What is "stuff?" Again, your energy budget will show you that you won't expect to get much out of it.
4. "I was wondering if that one panel would recharge the low bank for the 2 days I've been away." From what, to what? No, it appears that it simply won't, we discussed that earlier.
As Ken clearly said, the only thing a small panel like that will do for you is to keep you house bank topped off DURING A WEEK that you're away from your boat and everything is turned off. It will ONLY take care of the inherent discharge of the 1% to 2% drain of a wet cell battery. Really, that's ALL it will do.
Lance, you also mention "one bank" being one voltage and another a different voltage. Is this your house bank of two individual batteries? If they are tied/wired together, the two batteries are called a "bank."
Quote from: Ron Hill on April 23, 2009, 06:55:56 PM
Lance : Over the years I've noted that the solar panels aren't a straight math equation of 1.5amps per hour as they are charging @ 15 volts !!
We'll let the electricians on this Message Board decipher that for us...
The answer is twofold:
1. See my reply that discusses acceptance - it'll take much longer than straight math would infer.
2. A solar panel that's less than 1 1/2% of your house bank in amp hours does not need regulation, and the 15V is only occurring when there's direct sunlight. With the small amount of amps compared to the size of the bank based on this %, the bank can handle the small amount of higher voltage without damage. For any panel larger than that a regulator is recommended. The regulator controls the voltage out. Many have small panels and also have elected to include regulators. All regulators come with diodes to prevent outward migration of amps when it's dark out, but most panels also have the diodes built in anyway.
Lance,
Go ahead and use your backup charger. The most important thing to do is get some juice back in the batteries ASAP. The longer they sit the more the plates are subject to sulfation. But make sure you monitor the charging. Like Stu said those auto chargers can kill batteries. The important thing is to make sure it doesn't boil off the electrolyte. Add distilled water as needed. And when they're up to a healthy voltage disconnect the charger.
That's one way to do it, but before you do, find out what voltage the backup charger is putting out, because if it's only 13.8 V or if it's a constant higher voltage, you may not be following the guidelines to bring back dead batteries, which I referenced the necessary information for you to read. Ted's right ot do it asap, but doing it fast may not be doing it correctly.
Thanks for the info.
I have 4 AGMs organised into 2 banks. One is for house the other for starting. Here is what happens, and is on, when we are on the hook. While sailing during the day, we only have our stereo/GPS/VHF on. All other electric is off.
1) Interior lights (All LED now)
2) Anchor Light (LED)
3) Pressure water (As needed)
In the AM, we run the motor to:
1) Heat the water
2) Charge batteries.
My back-up charger IS an automotive; but, it has settings for AGM and variable voltage settings based on the charge remaining in the batteries. I don't intend to do a rapid charge. I'll leave it over night on a long term charge setting.
I think what people are missing is that this is a short term solution to my problem. The solar is a long term solution to our short term sailing.
When my charger is repaired or replaced, that will be my primary mode of replenishing the batteries. The solar will augment that and help keep the batteries up when out sailing for the weekend or long holiday's.
Here is the info on the Solar Panel (x2):
Pm Watts: 20
I pm Amps : 1.18
V pm (Volts): 17
High Efficiency Mono Crystalline
Quote from: pogmusic on April 24, 2009, 12:47:26 PMI have 4 AGMs organised into 2 banks. One is for house the other for starting. Here is what happens, and is on, when we are on the hook. While sailing during the day, we only have our stereo/GPS/VHF on. All other electric is off.
Completely Off TopicI would urge you to consider making three of your batteries into one big house bank and the other for a reserve. You will get longer life out of the new bigger house bank, and all with the same investment in lead. Indeed, with the addition of a small automotive bank for a new reserve, you could have a tremendous house bank capacity with all four of your AGMs and run your fridge all you want. I find it odd, at best, to hear someone who runs their fridge all week, but won't when actually on the boat, unless I'm missing something in your post which didn't include the fridge when sailing. Your boat, your choice, but...
The only one who I've ever agreed with about having split and equal house banks is one of our Past Commodores Dave Davis, who has four golf cart batteries in his OEM battery box, races a lot, rarely anchors or moors out, and doesn't want to add any more weight to the boat.
Quote from: pogmusic on April 24, 2009, 12:55:59 PMI think what people are missing is that this is a short term solution to my problem. The solar is a long term solution to our short term sailing.
When my charger is repaired or replaced, that will be my primary mode of replenishing the batteries. The solar will augment that and help keep the batteries up when out sailing for the weekend or long holiday's.
Here is the info on the Solar Panel (x2):
Pm Watts: 20
I pm Amps : 1.18
V pm (Volts): 17
High Efficiency Mono Crystalline
The reason I asked about your "backup" charger & continued to suggest that you repair your TrueCharge charger
first is because of the issue of "Is there life after death?" for seriously depleted batteries, discussed by Calder on pages 47 & 48 of the 2nd Edition of "
Boatowner's Mechanical & Electrical Manual."
Getting dead batteries back to life requires:
Equalization - which only your TrueCharge can do for you
and
Charging to full is required
before you equalize - which you could possibly do with your backup charger
After you've done this, if you've repaired your TrueCharge, you should check the electrolyte with a hydrometer after the batteries have rested.
You should also check the batteries after a day's use and leave a load on overnight and check them the next morning for voltage. You could well bring the voltage back up and they may appear to be fine, but you need to find out if they'll hold a charge over a period of time with a load on them.
Wile this discussion by Calder is for wet cell batteries, the following is from the Concorde / Lifeline battery website for AGMs: http://www.lifelinebatteries.com/manual.php
LIFELINE BATTERY OWNER'S MANUAL
Congratulations on the purchase of a new Lifeline battery! Lifeline has been the leading name in AGM (Absorbed Glass Mat) batteries since 1993. The quality and durability of the Lifeline battery series has been proven again and again in military and commercial applications worldwide.
# The AGM difference: 20% faster recharge than a conventional vented battery and gel cells.
# 100% maintenance free. No addition of water needed.
# Classified as "NONSPILLABLE"
# Tested to stringent military shock and vibration standards.
# Designed to reduce outgas under normal charging conditions.
Conditioning/Equalizing Charge: 15.6 volts for 8 hours
Conditioning/equalizing should only be done when the battery is showing symptoms of capacity loss. If conditioning/equalizing is necessary, first go through the normal charge cycle. Once the battery is as fully charged as possible, start the conditioning/equalizing charge. IMO, the size of your solar is not "
a long term solution to our short term sailing" because of the energy budget discussed above and your small panel(s), even if you keep your fridge off. 1.18 amps in full sunlight, times 5 hours per day = less than 6 AH! Even double that just keeps up with your lgihts and stereo, or whatever you're using.
With your robust chunk of batteries, if they are re-wired properly into the largest bank you can make, you CAN actually run your fridge when using the boat away from the dock. You plug in when you get home, so why not start enjoying the full benefits of the appliances you have on the boat when you're away from the dock?
As far as battery charging "in the morning" I recommend you read this, which will explain why you're not getting much into the house bank after a night on the hook because of battery acceptance. Even with a high output alternator (& I don't know if you have one) not much is going back in in the morning, although that hot water sure is nice, isn't it! See: reply #20 and the rest of this topic: http://c34.org/bbs/index.php/topic,4454.15.html It says:
"Let's say you have a 400 ah house bank. 20% of that is 80 ah, about what we've found we use on one overnight stay with the fridge running (400 X .2 = 80). That's enough "down" for the regulator to instruct the alternator to start pumping max amps as soon as the engine gets going.
"However, that same 20% is the HARDEST of all to put back into the house bank, due to acceptance and that "last 20% is the hardest to replace without shorepower." You can run your bank down to 50% and most cruisers use the 50% to 80% range of their house bank to minimize engine running time for charging. Therefore, we can get two or three nights on the hook with that daily 80 A draw down (we have 360 ah in our house bank)."If you rearrange your wiring a very small amount and change from the way-old two equal bank philosophy to a largest house bank you can arrange, you'll be in much better shape for your electrical system.
Good luck on your TrueCharge repair or replacement.
I am NOT an electrician. So, all of the numbers have no meaning. In fact they're confusing me. As I've said I have 4 AGMs organised into 2 banks. From what others have said with AGMs, you don't equalize them nor is there an electrolite issue. I MAY BE wrong, probably am.
That being said, all I wanted to do with my short term battery charger was to charge enough to start the motor and get my on board high out put charger working. It charged it well enough over night to start this morning. As my in-laws are in town and are afraid to be on the water, all we did ALL DAY was motor. Now, batteries are charged and I have an appointment with my electrician on Monday to fix my REAL charger.
I am very interested in doing the big bank theory; but, that will be for a later date.
Cheers!
Lance : I have 3 group 31 AGM batteries and as you said they(AGMs) never need to be equalized and do not self discharge. I have about 315 AH capacity (not including a starting battery) that seldom drain down by more than 40 AHs before I recharge.
They are maintenance free and have a longer warrentee period that any other type battery. They are going on their 6th year and show little wear (accepting a charge).
Don't know if you did any damage letting them get to a low discharge, but a load drawdown check after recharged, will tell you their health. Good luck . :thumb:
Quote from: pogmusic on April 25, 2009, 06:50:26 PM
I am NOT an electrician. ....to charge enough to start the motor and get my on board high out put charger working. It charged it well enough over night to start this morning. Now, batteries are charged and I have an appointment with my electrician on Monday to fix my REAL charger. I am very interested in doing the big bank theory; but, that will be for a later date.
Understood. Glad to hear it worked. That's great news. When the electrician comes on Monday, you may want to share these battery bank ideas with him. He may be able to get you "the big bank theory" while he's there simply by moving and adding a couple of wires to get at least three of your four batteries in one bigger bank now, and then you can ponder your future choices. At least this important enhancement can be done rather easily and with little time or effort on his part. You'll have a nicer boating and refrigerator season, too. :D I wasn't an electrician when we bought our boat, either.
Enjoy your 3rd Annual Memorial Day Brunch on May 25th.
All the best, Stu
Stu,
I have 390 Watts of solar panels that I am going to install. Will be able to run my stereo all day long and still display an anchor light at night?
Thanks,
Steve
STEVE : I BELIEVE THAT STU (AS KNOWLEDGEABLE AS HE IS) needs some more information.
Will the sun shine and how many amps does your stereo draw. Those two are starter guestions. :nail
For those that are waiting with baited breath..... My batteries held their charge well overnight Saturday after all day motoring. She started right up Sunday morning, we motored out into the wind <5 minutes running, raised the sails, turned on the fridge, sailed all day. When it was time to return, it was also time for the big test..... she started right up! :clap So, I think the batteries are fine.
Now, today I'll have the electrician fix the charger and look at converting to a three battery house bank. Thanks for all y'alls help. BTW, #2 bank had a higher charge than #1. Could that be due to the solar panel hooked into #2?
I might have some useful input on this issue. I installed two 54-watt Kyocera solar panels a year ago, and tied them into a smart two-battery charge controller. I have a Link 20 (now Xantrex) battery monitor. The panels provide a MAXIMUM of just over 6 amps, in full direct (overhead) sunlight. That maximum is rarely achieved. I actually get between 20 and 30 amp-hours of charge of the the panel on a typical summer day here on the Chesapeake Bay. I have two group 4D AGMs, totalling about 400 amp hours of (theoretical) capacity. I never run them down below 65 per cent of that number.
The 20-watt panel, in this same setting, would provide less than one-fifth of that total, or four amp-hours or so (that's just an estimate).
I like the panels, they fit well on the deck just forward of the traveler, and my batteries are always fully charged when I go to the boat after a few days away. I almost never plug in to shore power. I can anchor out an extra night or two without running the engine to charge the battery. Solar panels are a great idea, but we need to be realistic about their capacity to charge batteries.
George Alberts
Breezing Up, Hull no. 1471
Thanks George.
These are just to "top off" the charge and give a Little boost for our weekend cruising. When we move to the shore and live aboard, I'll have a different solar arrangement at that time. I got the 2 x 20w panels for free along with their regulator. Will not look a gift horse in the mouth. Well, at least directly.
Thanks for the feedback, Lance, and glad it worked for ya! Keep us posted, I've switched from holding my breath to crossing my toes - great exercise for the broken leg! :D :D :D