HOUSE BATTERIES

[TC]

I am looking for thoughts and opinions. I have had this boat since Canada Day 2007, and by the way, am enjoying it very much.

When I got it, it had two batteries, one crank, one house. ( The boat lived at the dock, the am/fm radio could only run on 120 volt. ) The batteries are Interstate Group 29's 210 reserve capacity ea. I bought one new battery and installed it as crank, then paralleled the I/State batteries as house batteries. They provide Res Cap of 420. They will last a 2 day weekend but not quite a three day stay. The date stamp on the I/State batteries is 2002 so these guys are entering their seventh season. Anything I have read suggests boat batteries run 3 - 5 years. They both test fine but I figure I'm on borrowed time.

I have a 1000 watt inverter which just runs the TV ( not much ), no A/C, so basically my needs are 12V lights, frig, and tunes.

So here's the deal. I have room for either three 12 volt house batteries or four 6 volters. Three I/state @ 210 ea will give me Res Cap of 630. Four 6 volts ( ie Trojan T-105's ) @ 447 ea will give me Res Cap of 894. ( don't forget, series/parallel )
The difference is buying 4 batteries verses 3 and added cables.

Now I don't need to power the entire anchorage. Most boating is weekends on the hook, and holidays where the boat may sit 2-3 days beween running. I also carry a small portable gen.

Do I need all the power, or will 3 12 volters fill the bill. I know the phrase "too much power is sometimes still not enough".

So guys/gals, what do you use? What has worked, or not worked for you in the past? I'm all ears.

[g36]

on my 32 we anchor out just about every weekend and numerous extended nights during the spring through fall time frame. i have 4 t105's that i have set up with a switch fed from 1 engine. on the other is a deep cycle starting battery on the other engine. this can be paralleled through the "black box"if needed,but i have yet to need to. my generator has its own seperate battery also. the t105's give me plenty of power to run all my 12v stuff and invertor stuff too. the main thing with batteries lives are how deep they are discharged,. this will affect how long they will last. the trojan golf cart batteries work great for me and i will use this same setup again whenever i need to replace. i do have an electric golf cart at home and have tried different golf cart batteries and although these are expensive my experience is they are worth it. if you are already pushing your interstate batteries to their limit then you need more capacity. i dont think you would be sorry for purchasing the trojan t105's. just my opinion.

[ready123]

I anchor out every weekend and use fridge, stereo, sat. radio, DC lighting. My setup is 3 Can Tire marine starting batteries one for each engine with parallel switch and the third for the Onan 3Kw generator only.

I have a Lifeline AGM battery 4DLT for the house battery which handles the frig and small inverter, lights are from engine batteries. I charge them with a Xantrex Truecharge 40 amp 3 bank charger (genny charges it's own battery).
Battery info:
http://www.lifelinebatteries.com/marineflyer.php?id=6
http://www.mobilepowersolutionsinc.com/

I find that I can frequently last the weekend without charging the house battery.... freezer keeps meat frozen.
I also have a battery switch that will allow the Alternator to charge either the engine battery or the deep cycle while underway. I use that when I am on longer trips with frequent travel days. When I am on my 2 week vacation I run the genny every morning for about 90 mins to power the microwave for lattes and charger... and hot water for the wife.

My battery box runs between both engines and takes up most of the space from the forward engine room bulkhead to about 2' from the Onan which is at the aft bulkhead. the cover of the battery box is substantial enough to stand and work from. The box is open sided to allow for air movement.

I am very happy with the AGM.... it will hold it's charge all winter in the boat. I leave all batteries in the boat fully charged after haul out and disconnected.
The AGM cost about $450 but the extra power that it affords me is comforting along with the fact that it is one of the best kinds of batteries to have as a house battery as it handles discharge cycling well. The AGM is starting it's fourth year and still reads like new.

[randyp]

Good advice from both on batteries. I've always used WalMart Group 29 MAXX-29 batteries - one for cranking the single Chrysler 318 and 2 in parallel for the house bank (250 AH capacity). I just changed them out after 5 years. Last year I installed a Blue Seas ACR (auto charging relay) to avoid the inevitable mistake of leaving the single battery switch on "all" and draining the whole shooting match. With the ACR installed I just leave the switch on "2" (House Bank) without worrying about discharging my start battery. Underway (on alternator) or at dock (plugged into charger) the ACR automatically handles all charging needs and I just hook up the charger lead to the house bank. A good $90 insurance policy. We spend most weekend on the hook and the 2 WM batteries handle the Norcold fridge, inverter, lights, stereo, etc with plenty of reserve. On longer times on the hook I use a portable gen (Honda EI2000) that I run outside on the swim platform or a convenient wall or dock.

[ready123]

Last year I installed a Blue Seas ACR (auto charging relay) to avoid the inevitable mistake of leaving the single battery switch on "all" and draining the whole shooting match. With the ACR installed I just leave the switch on "2" (House Bank) without worrying about discharging my start battery. Underway (on alternator) or at dock (plugged into charger) the ACR automatically handles all charging needs and I just hook up the charger lead to the house bank. A good $90 insurance policy.

I was going to use an ACR too but the Lifeline guys were against it as ALL batteries were not AGM. With warranty concerns and no experience with the AGM battery I passed on the ACR. I am living with the pain of a manual switch and the times I forget to charge the house battery while underway. Not a big deal really as I have an onboard genny.. though being 30 yrs old it does burn more fuel than a modern one.

[jddens]

I have 4 - 6 volt for house (2 sets in series) and one big 12volt for cranking. I have a 2KW Heart inverter. Rarely spend more than 2 days on the hook and don't have a refer. With just the wife and I, an ice chest works fine (and keeps the beer at the perfect temp).Use the inverter for LCD HD Tv and coffee pot and that's about it. Everything else is 12volt. I do have an electrasan treatment unit and that sucks ALOT of amps. All Batts are combineable via 2 perko switches. Starting Batt is isolated but can be combined if required. I also have a 120 amp altenator on the port engine that charges everything when underway via a first step regulator. Smart charger charges everything when on shore power......all in all a great setup with lots of reserves and fully automatic...........

And because I'm into over kill, I also have a emergency starter pack with inverter stored under the dinette...............just in case.......John

[foofer b]

If I am underway, running on say, battery bank one, will both banks charge from the engine or do I need to switch to both?

[gjrylands]

Unless you have a battery isolator in the system you will only charge the bank that is running the engine. You would need to switch the selector switch to the bank you want to charge.

[randyp]

If you go the ACR route you don't have to worry about switching. Just leave the switch on house bank and the charging sources (alternator, charger, gen, etc) will be sensed and direct a balanced charge to either bank. As stated in the previous post, you need to have all batteries be the same (flooded, agm, etc), but I think the technology may have adapted to mixed batteries. It's a great way to have some piece of mind, and is a hell of lot cheaper than a new or rebuilt alternator because someone threw the switch to or "off" when underway.