House Batteries

[dhwort]

I have a 2015 Thor Palazzo.
Our batteries will not stay charged in storage. Neither house or engine. I finally installed charger/maintainers to both house and engine bats. These will charge to full and then stop charging. Then when charge drops will turn on again till 12v is reached. I don’t know if they are available for 6v.

[RVGeek]

There are two types of popular testers. The hydrometer is best and measures the specific gravity. The second is a 100 A battery load tester and Harbor Freight (a.k.a, the Candy Store) has a decent one for $20.

Originally Posted by JGallagher

Thanks everyone for all of your replies and suggestions.

I will likely do what RVGeek suggested and purchase 2 new group 27 batteries from Walmart or BJ's and be done with things.

I am waiting to receive my battery tester from Amazon just to see what the individual cells read before I buy the new batteries.
Unfortunately, tester not scheduled to arrive until early May.
Doesn't really matter though, nowhere to go!

I'll report my findings once the tester arrives.

[JGallagher]

Hi RVGeek,
I just received an update from Amazon that my hydrometer should arrive Tuesday.
I'll post some results later this week.

James

[petefoss]

Do we really think the 100 amp load test is the right measurement? How long is the load applied? I would think a load discharge curve at a moderate current would be a better test.

[Bob Denman]

Have you checked the water level in them?

[RVGeek]

Hydrometer is best. Messy, but quantitative.

One could measure the capacity with a lighter load. The ampere-hour, AH, rating of a battery is based on a 20-hour discharge with a constant current (AH/20, e.g., a 100 AH battery would be discharged at a 5 A rate.) until the battery reaches 10.5 volts and that is the most accurate means of testing the capacity, but shouldn't be done often as it will shorten the life of the battery. It's sort of like testing to determine how good the battery WAS. The 100 A load tester is usually applied for 10 seconds and gives an indication of the reserve capacity in a less destructive way. It's not very quantitative, but will indicate a weak battery.

[JGallagher]

After 4 hours of charging, ONE cell out of 12 tested good with the hydrometer.

I knew that batteries were done but just had to confirm it to myself.

Strangely, the acid in one of the cells was brownish, almost muddy. The rest were clear.

Thanks again for all of the helpful replies.

[RVGeek]

The cloudy electrolyte indicated that cell is sulphated and that battery is DOA. All cells should charge at approximately the same rate, as indicated by the specific gravity reading. It sounds like both batteries should be replaced.Sorry!

When my 23U was delivered, both batteries were sulphated (all cells showed cloudy electrolyte) and I contacted the battery manufacturer, who denied the claim stating that the batteries had been drained and left uncharged at Thor. (He had had several similar complaints.)With some effort, and a convincing technical argument, Thor paid for a new set.

Originally Posted by JGallagher

After 4 hours of charging, ONE cell out of 12 tested good with the hydrometer.

I knew that batteries were done but just had to confirm it to myself.

Strangely, the acid in one of the cells was brownish, almost muddy. The rest were clear.

Thanks again for all of the helpful replies.