High Battery Specific Gravity

[gypsmjim]

Here’s one for you battery experts…

I always disconnect the shore power when we leave the trailer, disconnect the battery and turn on the solar panel. For the first time ever, I left the battery in all Winter.

The battery was at 100% all Winter. In February we camped in the snow for a weekend. When we left I screwed up – I left the battery “on” and forgot to turn on the solar. So the battery was subjected to the parasitic drain with no charging capabilities.

Late March the voltage had dropped to 12.0 and the sp.g was at 1.15. When I discovered my mistake I turned the battery off and put the solar back on. It’s now a month later.

Today the battery was at 12.7 volts, but I couldn’t get an accurate reading on the sp.g. The needle was over the top – the highest reading my hydrometer shows is 1.3. Typically all my batteries show about 1.275 when fully charged. I would guess it was in the 1.35-1.4 range. All the cells were the same and all had water above the plates.

Do I have a problem? (that solar panel sure works good…..LOL)

[Mustang65]

Originally Posted by gypsmjim

Here’s one for you battery experts…

I always disconnect the shore power when we leave the trailer, disconnect the battery and turn on the solar panel. For the first time ever, I left the battery in all Winter.

The battery was at 100% all Winter. In February we camped in the snow for a weekend. When we left I screwed up – I left the battery “on” and forgot to turn on the solar. So the battery was subjected to the parasitic drain with no charging capabilities.

Late March the voltage had dropped to 12.0 and the sp.g was at 1.15. When I discovered my mistake I turned the battery off and put the solar back on. It’s now a month later.

Today the battery was at 12.7 volts, but I couldn’t get an accurate reading on the sp.g. The needle was over the top – the highest reading my hydrometer shows is 1.3. Typically all my batteries show about 1.275 when fully charged. I would guess it was in the 1.35-1.4 range. All the cells were the same and all had water above the plates.

Do I have a problem? (that solar panel sure works good…..LOL)

My first question will be, "What is the temperature of the battery?"
Secondly... Is it a quality hydrometer? (not the one with all the colorful balls in it?)

The1.275 is based on a battery temperature of 70 degrees. There are different formulas you need to use if the battery is not at 70 degrees.

Don

[gypsmjim]

The hydrometer is one like this:

http://www.ebay.com/itm/HYDROMETER-B...MAAOSw7NNUEddm

I hadn't thought about the temperature. I would guess it was about 50 F. It was probably about the same temp a month earlier when I got the 1.15 reading.

(the link above got screw

[Mustang65]

If you use the general calculation, you subtract .03 for each 10 degrees below 70 degrees F.

As mentioned, the battery temperature was about 50 degrees and the SG was 1.35sg - .06 = 1.29SG

I guess that the numbers are not that far off... based on the current results

Don

My Registry

RVing with SOLAR

[gypsmjim]

Thanks.....I should have thought of that.