Battery Problem

[wealthwise]

I have a problem with a starter battery at least I believe it's a starter battery. It shows cold cranking amps so it's got to be a starter battery, it's connected to another battery that's fully charged over 12 volts. I had to add distilled water to the cells I"m not sure if they could be bad, I tried charging it in regular and trickle but I couldn't get past 12.70 volts, last night It was at 12.55 and today it's at 12.12, could this battery be bad? I don't have a hydrometer to test it, do you think it needs to be replaced? Being that's a starter shouldn't it recharge with the alternator or is it controlled by the isolator?
Thanks for any help.

[wealthwise]

One thing I'm trying to figure out is which battery is for what? Is thet sealed battery in the rear the starter battery? Is that how it works which pushers? When I disconnect it the starter does not engage, so then I guess by brilliant deduction that means that the two batteries in the front are house batteries and provide power to the jacks and slide. That's got to be how it is, I can't imagine any other explanation? So if I wanted to test the Alternator does it work the same way with any car, just disconnect the negative cable from the rear battery and if doesn't stall it's fine? I did that and it didn't stall.
Thanks

[wealthwise]

Good to know thanks for the tips.

[westend]

Any battery will work, it's the performance and longevity that are different between different types and sizes of batteries that differ.

If you have another 12v battery, paralleled, that is older and put the new battery in, chances are, the new battery, along with the older one will be toast within a year or two. Mixing different age batteries is to be avoided.

I would count my lucky stars on getting a free battery from W#almart and go right back for a new one of the same make and size. I think you're looking at $80 or so for a new one and it will be worth the longevity and peace of mind.

[tenbear]

Glad you got a new battery. It is the type most rvs come with, a compromise between a starter battery and a deep cycle battery. No reason you shouldn't use it.

In the future, be sure to check the fluid levels regularly and keep the connections tight.

[wealthwise]

Battery was bad had at least 2 cells that were dying, the battery was almost 3 years old and carried a 12 month replacement, Walmart replaced it with the closest possible model, I need to know if there is any reason I can't use the replacement.

Here's the details.

Old Battery- Everstart Marine Deep Cycle
Marine Cranking amps 720
Cold Cranking amps 600
amps 115

Replacement Battery Everstart Marine Deep Cycle
Marnine Cranking amps 690
no cold cranking amps info
101 amps

The battery supplies power to the HWH jacks pump and is connected to the battery next to it by a black wire connected to Neg terminals,, the red terminal has a harness wire connected to it I'm not sure where that goes, in the rear their is a sealed cells heavy duty battery that's by the power supply, but when I disconnect it, the house lights etc, still work, so I guess that battery is supplying power to some of the house, I really need to figure all this out, anyhow will this replacement be ok?
Thanks for the assistance.

[wealthwise]

I will take all these suggestions into consideration.
Thanks

[Ron_Nielson]

You might want to invest in a battery load tester. They're pretty cheap and having one on hand will answer the question very quickly with no need to go to a store/shop. Here's one: Battery Load Tester

[mena661]

I would look up battery shops instead of automotive stores. Maybe call a golf course or two and see who they recommend.

[gatorcq]

Take it to any automotive store. They will check it for free.

[wealthwise]

westend wrote:
Back in my early car and truck repair days, we would test a battery for a bad cell by 1) charging the battery 2) striking an arc across the posts, instantaneously. If the voltage measurement drops significantly, it was indicative of a bad cell.

It's worth a shot, what do I got to lose, thanks for the tip.

[westend]

Back in my early car and truck repair days, we would test a battery for a bad cell by 1) charging the battery 2) striking an arc across the posts, instantaneously. If the voltage measurement drops significantly, it was indicative of a bad cell.

[wealthwise]

I think it may be a dead cell, but then again who knows.
Thanks anyways.

[JamesJudasPries]

Agreed, Voltage drop that fast is probably a bad cell, or a pile of sediment starting to short cells. Just get a new one.

[time2roll]

If the battery was sitting disconnected and dropped from 12.7 to 12.1 one day after charging.... save yourself the testing and get a new battery.