House Battery - Should they last more than a year?

[SierraHawk]

I have owned my SMB since 2004. On average, I have had to replace the Series 27 AGM house battery every 18 months. The specs on the batteries are the same but the labels are different (Sears/NAPA/Bass Pro/etc). I replaced the house battery last August. It was a NAPA product. I took the battery back to NAPA today. It had a 3 month full replacement warranty and a three year pro rated warranty. What that means is that I will be paying around $100 each time a battery dies. As utilities go that is pretty cheap but I don't want to be forced to cough up $100 to replace a defective battery.

1) How long are your house batteries lasting?

2) What brands seem to last longer?

3) Is there a practical alternative to the Series 27 battery?

[Ford_6L_E350]

If they are only lasting a year or so, the question is 'What is killing them?'

- Are you regularly running them down?

- Do they sit idle and self discharge over months?

- Are they overcharged?

My two group 27 batteries have been replaced once in 8 years and that was because of an electrical fault that didn't charge them for ~6 months.

Mike

[Ultrasport12]

No matter what the brand name (and it seems like you have tried a bunch) is you should get at least three years out of them and even more if they are well cared for. Mikes eight years is exceptional but he takes really good care of his van.

Mike is spot on with what he said.

Over or under charging?
Never over 14.7 volts ever and closer to 14 is easier on them.
Low on water if they are not AGM or gel cell.
Old date code batteries when you bought them?
Possible draining them too low before recharging?
AGMs cannot take going below 12volts as well as wet batteries can.
Not charging them or using the van for long periods?
(Batteries do go dead just sitting even when unhooked.)
Using them when they are not fully charged to start?
Something drawing them down, even something really small.

Understanding and maintaining batteries is the key to long life.

[LenS]

4-5 years and all of the above. Are you discharging them more than 50%? For that short of life you must be draining them or not maintaining the water level.

[dmeade0]

One small electrical drain are the Propane and CO detectors. You can get around this by pulling the proper fuse. Leave the fuse in the coffee cup holder on the doghouse so you'll be "reminded" to put it back in.

As for life expectancy, I just replaced my original house battery after 7 years. The trick for its' long life was that I've got solar so it's recharged every day.

David

[daveb]

Suggest reading these links.

http://www.batterystuff.com/kb/articles ... asics.html

http://www.windsun.com/Batteries/Battery_FAQ.htm

[Viejo]

This is also an excellent tutorial on 12V systems...

http://www.marxrv.com/12volt/12volt.htm

[yvrr]

David mentioned pulling the fuse for the propane and CO detectors. That was mentioned 10-11 years ago (before solar) but I thought that pulling the fuse was a "non-elegant" solution so I long ago installed a DPDT switch which lets me turn these detectors off without the need to get under the sofa to pull the fuse.

Our battery lives have been:
Original -Lifeline 2 years, 4 months
Second - Lifeline 3 years, 5 months
Third - Lifeline 3 years, 6 months
Current battery is a Deka installed 1 year, 3 months ago.

We have solar and so I don't typically bother much anymore with turning off the detectors. The solar keeps the house battery topped off and I rarely (once a year?) drop the house battery to less than 12.2v. Last time I was at SMB West, Peter told me that it is a good idea to plug into shore power overnight every couple of weeks.

[sdwindansea]

Originally Posted by yvrr

...Last time I was at SMB West, Peter told me that it is a good idea to plug into shore power overnight every couple of weeks.

Was there any explanation as to why this is a good idea? I was under the impression that both Solar and plugged in are both capable of achieving a full charge on the batteries while the alternator only really achieves around a 90% charge. I haven't plugged in since we got solar. Thanks.

[Viejo]

It's not so much calendar time as it is the number of discharge cycles and depth of discharge that affect battery life. A week spent in the driveway plugged into a float charger doesn't count near as much a week of camping with daily deep discharge cycles each day. It all depends on how much you use your van.

When I say 'deep discharge' I mean down to 12.0 volts. Anything lower drastically reduces battery life. It creates a vicious cycle where the battery holds less charge so you draw it down further each day causing it to hold even less charge and so on.