Replacing batteries

[rappareems]

I have a simple two battery set up.  last time I replaced the batteries I put in one cranking and one deep cycle.  It seems after I did that I saw where it was recommended to simply use two deep cycles as you are not doing serious cranking to start the 25 hs. diesel.  Batteries are three years old.  Cranking battery is dead and deep cycle is weak.  Suggestions?

[RV61]

Mark,
I have the two battery setup and just replaced with 2 dual purpose 27s to give me a few more amps. I Plan on putting in a separate cranking battery in the future. In the mean time I carry a jump start battery pack as insurance in case we forget to move the switch from all to 1 or 2 when anchored or sailing for extended period of time.

[sail4dale]

I had that decision to make about a year ago and I elected to go to 6 volt "golf cart" batteries (4) if for no other reason that I can lift them out myself if need be.  I looked into a starting battery circuit and instead went to Costco and for $55 bought a battery, inverter, compressor pack that recharges from AC or a cigarette lighter socket.

I keep this pack in the boat when cruising and at home for inflating tires when needed.  I doesn't weight that much and has enough stored power to start my M35 engine at least 4 times.   Works well for me.

[jpaulroberts]

I have just upgraded to a three battery system. I am using two sealed group 27 deep cycles linked as one for my house, and a group 27 granking battery for my engine. I will probably add a diode so I do not have to switch back and fourth to charge the two systems.
Jerry

[Paul Bosquet]

One of the first thing I did when I got ELIOSSO was to upgrade the batteries. I opted for golf cart batteries. Purchased 4 TROJAN T105 that fit nicely into the battery locker under the settee. I also have a starting battery behind the engine. I also upgraded the alternator to 100 with external regulator as per Jim Moe's recommendation. At the dock, an TRUECHARGE 40 keep the batteries well charged. The system has worked well for more than a year and I don,t have a fit when I see a light on.
Paul

[Ron Hill]

Mark : Do as Paul suggested and go for the 4 golf cart 6V batteries.  After you get those in then you can look into a 12 V starting battery installation.

That 6V installation is in the Mainsheet tech notes and Projects list.  

[Stu Jackson]

Mark

Re: Serious Cranking - you're right, turning over one of our engines isn't a big deal.  There's no reason not to be able to use a deep cycle battery for the intermittent and short duration start needs.  While we on Aquavite have a large house bank and a separate start battery, I often use the house bank to start, because the start battery is essentially there for when we're out on the hook for an extended period and have depleted the house bank, and so the start bank is there for a "ready reserve" which was its intended purpose to begin with.

If you look back at the electrical and battery discussions on this message  board, you'll note that Dave Davis once asked about his (4) 6V golf cart battery setup, and whether having 2 house banks of deep cycles was OK for "switching" house loads daily and for starting.  The answer is that a starting (technology) battery isn't used at all if you have a double house bank setup.  In fact, this is exactly how Catalina is still making C34 electrical systems, with the two 8D batteries.  Many new owners simply tie those two together for a larger house bank, and then add a new start battery, or they keep them that way and switch off daily.  Start battery technology IS used when you have a larger house bank and a separate starting bank, where the start battery is used JUST for that purpose, as noted above.  So, the choice still is: 1) "split" banks, either used for house and start; or 2) dedicated house bank and separate start bank.

Of course, this choice also depends on your energy budget, and how you use your boat.  If a single battery suffices for your estimated "away from re-charging source," then you're fine.  I still believe that a single battery, even an 8D, is really pushing it for even a daily sail if you have and use refrigeration, based on a simple energy budget: you end up drawing down the battery excessively, when having a larger house bank will reduce the draw-down and extend the life of the batteries.  All this has been previously discussed here on this board.

I also discourage using the ALL position to start the engine, since either bank should be capable of doing so.  If it is NOT, you need to consider why not and find out how to fix it.

I believe that there is adequate information not only on "electrical" and "batteries" here on the MB, and the recently posted electrical systems information in the main website "Projects" section, for all of us to be able to understand and design their own systems, always remembering that there is no ONE way to do it "right," because it all depends on how you use, or intend to, use your boat.

[Ron Hill]

Interesting discussion!

I just threw out a 1995 SAIL magazine article that did a test on 4 large batteries.  At first they were all (4) tied electrically together (the ALL position) and then they were tied into 2 separate banks (bank 1 and bank 2) and used separately by bank.  
The conclusion was that all tied together was better and increased battery (cycle) life.  

If you switch the battery selector switch while the alternator is putting out more than 20amps, you will arc across the switch and dirty up the contacts - making for poor switch contact in the future.

I leave my selector switch in the ALL position and still use the starting battery (which can be separated/isolated).  

[Stu Jackson]

Ron's right, any larger bank of batteries will last longer, given the same daily (cycle) use.  Period.

If you do a search on this board for Calder, you'll find a longer explanation of that at:

http://www.c34.org/phpbb/viewtopic.php?t=973&highlight=calder

Better yet, buy the book and read the whole thing.

Also, remember that how your particular boat is wired and set up is very important to know and understand.  For instance, Ron mentions using his switch in the ALL position.  He does that to combine his two house banks together, because, as he says, he has a separate starting battery, that doesn't go through his 1-2-B switch.

His wring is very different than mine.  I have a 1-2-B switch, but #1 is the start bank and #2 is the house bank.  It would make no sense for me to use ALL ever, since I want to use either #1 or #2, but NOT both.  I also have a combiner between my banks, NO DIODES, for charging by my inverter/charger (one output) and my alternator (also ONE output).  The charger goes to the PDP of my house bank, the alternator output goes to the #2 at the back of my 1-2-B switch (which is essentially the same position, electrically speaking, as the PDP).

So, PLEASE be careful when describing operations and asking and answering questions, especially about electrical systems.  My feeling is that detailed electrical questions about how to operate specific boats can't ever be done without a wiring diagram.  Other than that, as you've seen, we all will be glad to share our electrical experience and ideas.  Don't forget to check "Projects" out for more great electrical information.

[reedbr]

When I bought my boat in 2002, it had one old 4D battery and one newer group 27.  Both were shot, so in 2003 I did a lot of research here on golf cart batteries, a third starting battery, charger, alternator and wiring upgrades, etc.  I finally just bought two standard 4D wet cell lead acid batteries from Batteries Plus for $110 each.  My theory was to see how it goes, and upgrade if I run into problems.  So far I'm into my third season with no problems.  I even still have the original Flyback 20-3 charger.  I would recommend starting with the stock 4D or golf cart batteries (a simple change) before doing any major upgrades.  I'm a KISS person.  Some additional notes on my usage and environment:

(1)  I do stay out on the hook overnight and sometimes most of the following day.  No problems starting after using lights, refrigeration and cabin fans all night/day.  I've got three kids too, so that's drinks, lights, fans and water pressure for five of us.  I do not have an inverter nor a microwave.

(2)  I do go cruising for a week each summer, out on the hook every night, no problems so far.

(3)  I do not leave my boat plugged in while I am gone.  I don't like 110 AC running through my boat while I'm not there, so the batteries don't charge in my absence either.  I would like to get a solar panel but haven't so far.

(4)  If I don't run my engine much in a weekend, I'll plug the boat into shore power for a few hours before I leave to make sure I leave the batteries pretty well charged.

(5)  With light winds on the Chesapeake, usually I get an hour of engine running (i.e. alternator running) per day.

(6)  I have been alternating between batteries 1 and 2.  That is, I'll run all night on #1, charge it the next day with engine time and switch to #2 for the next night.  This always gives me a backup starting battery, but I've never needed it.  I've always been able to start with the battery I used all night.  However, I think for this year's cruise I'm going to run with the switch on "both" and carry a portable jump-start unit as has been suggested by others.

(7)  Those 4D's are heavy.  I'm relatively young but I still strained to move those units aboard and in position.  They have never moved since I put them there though.  Each winter I make sure they are charged and then I completely disconnect them (bilge pump, common ground, everything is disconnected).  Sometime mid-winter I'll stop by, check on the boat and charge the batteries with a car charger for a few hours, but other than that they sit on the cold boat all winter.

When I started this experiment, I estimated battery life at 4 years.  I figured if my poor usage practices shortened my battery life by a year (down to 3 years) I could live with that.  It would still be cheaper than the upgrades.  Like I said though, this is season three and so far so good.

By the way, the only reason I didn't go with the golf cart batteries was price.  I just couldn't beat $110 for a 4D.

Good luck with whatever you choose, but I do recommend getting rid of a group 27 "starting" battery as your second battery.

[Steve S.]

Mark:

Like, Brian, I like the KISS method.  I put 4 Trojan 105's on position 1 and a Size 27 on position 2.  If I am heading out for a week, I start her on position 2 and then switch to "both" while I am motoring (be sure your 1-2-B switch is a "make before break", almost all are.)  When anchored, I put her on position 1.  I was just on the hook for 4 straight days and while I did a share fare of motoring up rivers, esp. the Chester, I had the refer on the whole time and no problems, (and I have the stock alt!), the 105's are great.  For day sails and weekends, I just leave it on "both" and forget it.    

While the 105's are a little more ($70-90 each x 4) they are a good value.   What's a couple or 3 hundred for peace of mind?

[Roger Blake]

My 27's died on me...after much research, I chose to go with 4 Trojan 105s (6 volt golf cart batteries...2 each wired in a series). I also replaced the stock battery charger (which cooked the batteries to start with) with a TrueCharge 20. To install the Trojans, I had to expand the stock battery boxes by about 1" each...just cut them in half and fiberglassed in a spacer. So far so good.

[captran]

We just finished our 6th summer on Voyager.  Have a seperate starting battery for back up, which I replaced this year.  It was almost 6 years old.
 Have two 4Ds which are now 3 years old and did fine all summer.  Put about 99 hours on the motor for a full 2 months out, so that averages about 1.5 hours per day.  A marina once or twice a week and have a true charge 40.  Used the link 20 to monitor daily and keep a running log of condition 8 am and pm.  Used the inverter alot the first have of the summer so that my son could play video games.  (yeah, after 16 years of cruising, he's rather be watching TV- and he ended up going home to Grandma for the last month.)  Am thinking more about the golf cart battery idea because when you do have to replace them, those 4D's are heavy!)

[Mike Vaccaro]

Battery/DC electric rules of thumb:

1.  One large bank is better than separate smaller banks.  As with any engineering project, simple is always better than complex!
2.  A separate starting battery is a good idea.  There are many different ways to accomplish this, but the best is dedicated "maintenance free" (e.g., AGM) battery located near the engine.  Check the project page for ideas.
3.  All wiring should be properly fused and switched (including the "main" distribution wires).  ABYC guidelines are a good start.  If you're not familiar with electrical wiring or maintenance, it's not rocket science!  A good book on the subject is worth the money and will save you headache--even if you hire the job out, you'll have a better idea of what's going on with your boat.  
4.  Wiring should be properly sized IAW with a wiring size chart for either a 3 or 10% current drop.  Shorter runs are better than longer runs.  Wiring charts are available on line or in most marine catalogs.
5.  Only tinned wiring should be used in a marine environment.  All connections should be properly CRIMPED for STRENGTH and SOLDERED for JUICE.  A proper marine or aviation grade shrink seal will produce a connection that will last for decades.  Older Catalinas did not have tinned wiring, and connections used inexpensive automotive components.  In a salt water environment, any non-tinned wire older than five years is suspect.  Non-tinned wire will corrode INSIDE the insulation.  This corrosion won't be visible and can only be detected with a proper resistance/continuity check of the wiring with a multi-meter OR when the wiring shorts out.
6.  Golf cart (6V) batteries wired in series are a good alternative to heavier 4 and 8D batteries.  The standard Catalina 34 Mark I battery compartment can hold 4 for a 440 amp hour bank.
7.  Planning a battery bank starts with an electrical budget--spend the time to do the math to find out how much capacity you need.  Plan on using 50% of the capacity and you'll extend the life of the bank by avoiding deep discharge--e.g., if your budget is 200 amp hours for a weekend trip, install a 400 amp-hour capacity bank.  Lot's of good discussion about this on the web.  Best bet:  Google for "energy budget" or "planning boat electrical system."  Lot's of good discussion on the sailnet.com website as well.  
8.  A good multi-meter is a necessary tool for proper electrical maintenance, avoid inexpensive models.  Any model built by the Fluke company is a good place to start.
9.  A good battery monitoring system is worth the money.  A good example is a Link 10, 2000 etc.  It is essentially a "health monitor/fuel gauge" for your DC system.  These systems are a bit expensive, but will pay for themselves by saving just a couple of batteries from early replacement.
10.  Keeping batteries properly "topped off" is the key to long life.  This is best accomplished with a good charger powered by shore power, or a solar/wind system, or a good three stage regulator on a properly sized alternator.  An ideal system uses a combination of two or more of these.  Keep in mind that there is a limit as to the maximum size alternator small diesel engines are capable of running.  With the Cat 34, earlier boats equipped with the M-25 variants are limited as to how much of an alternator they can drive.  This is not as bleak as it sounds, however, because at the typical RPM range that we operate a 60 or 75 amp alternator can be more efficient than a larger alternator.  The key is a good external, three-stage regulator.

I'm sure other folks have other ideas to add to this list, so please chime in!

Cheers,

Mike

[Footloose]

As Mike said in his reply, the wires should be soldered and crimped.  I replaced all the connectors on my charging/starting circuit this weekend.  It is an easy project.  I still have the factory wiring on a fresh water boat.   When I hit the start button the first time after putting everything back together, I almost fell over the transom as it started so quickly.  Definitely worth the hour or so of time and the cost was way less that the cost of a tow.