Battery issue?

marknjudy

I know this has been duscussed ad infinitum but can't find what I'm looking for. My battery discharges to 12.2 volts in a month with battery disconnect switch in the off position (not connected). Normal? Not normal? Stamdard issue dealer battery. Can someone aim me at that thread?

pthomas745

Here is a search for battery discharging:

https://www.google.com/search?q=battery+discharging+site:http://tab-rv.vanillaforums.com/&ie=utf-8&oe=utf-8

Here is another one with discharging with switch off:

https://www.google.com/webhp#q=battery+discharging+with+battery+switch+off+site:http://tab-rv.vanillaforums.com/

marknjudy

Thank you! I'll check those out

Ratkity

I know lead acid batteries need a maintenance charge once a month, but I don't think it goes to 50% that fast. Check your cells for water. Add distilled only. The advantage of AGM batteries is that they lose little charge in a storage situation (cut off switch).

ScottG

Batteries will lose their charge when they sit, even with no load. How much seems to be influenced by the age and health of the battery. A couple of overly deep discharges can greatly hasten their decline.

In my experience, new batteries do not lose their charge quite as quickly as you describe; failing batteries, however, can lose it much more rapidly. I'd guess yours is still serviceable, though not in peak condition.

Like Ratkity said, start with checking the water. If you have a charger with a "reconditioning" function you could give that a try as well.

marknjudy

I'll check the water level tonight. Thus far, it hasn't suffered a deep discharge as we've pretty much camped with electrical hookups every time we go out. I think the maintenance charge is probably part of the issue, and I need to get a battery tender to do that effectively. It's only a year old and, to my knowledge, has never been allowed to drop below 12.2. I kind of hope it's bad so I'll have a better excuse (oops! EXPLANATION) for switching to an AGM battery.

Michigan_Mike

Ratkity said:

I know lead acid batteries need a maintenance charge once a month, but I don't think it goes to 50% that fast. Check your cells for water. Add distilled only. The advantage of AGM batteries is that they lose little charge in a storage situation (cut off switch).

Agree....  And when the wet cell batteries are left unattended and on a charger/tender it's important to check the water level as it does heat up and will evaporate over time.

AldebaranJill

My first battery in my T@B showed similar behavior after first year - and it was because the WFCO 8735 typically topped out at 13.6V which only was able to charge battery to 70% state of charge (via measuring specific gravity of cells). Continually only charging to 70% will lead to premature battery death. I bought a NoCo Genius Charger to insure fully charging batteries on shore power and generator. I put it into Cold 12V mode, and top off with a few repair cycles. This gets batteries to 100% state of charge (specific gravity measurements).

marknjudy

That could be the issue. Water levels are great. No phantom draws with Battery Switch off. @aldebaranmodel did you choose? A quick look showed quite a selection and price ranges.