update on stinky battery.

I finally got around to removing the battery caps and all the cells were a little low on water, the plates on one cell was almost exposed. So I filled battery, used about a pint of distilled water. The cell that I added the most water showed discharge with hydrometer, the rest showed full charge. I would expect that.

Now here is the brain teaser. Both are marine type batteries. One is the original in dump trailer, the other I used occasionally on my electric wench and trolling motor. The original battery measured around 835 cca when it was newer. Today it measured in at 650cca and 12.79v after being off the crapsman smart charger a few days. The smart charger didn't turn off cooking the HS(hydrogen sulfide) out of battery.

I removed the second marine battery that was in parallel with the first. The second battery is a cheap excide. It measured in at 530 cca and 12.77v. All cells passed the hydrometer test. When new, the battery measured in around the same cca.

Now go figure, Stinky battery shows better cca than newer excide, slightly better voltage, nothing to brag about.

Now is the time to connect my batteryminder 12248 to the stinky battery and run it through many desulfating cycles to see just how good the charger is and what it does to the dry cell. I'll report back. I have never seen battery bring a battery back from the dead. Not sure my smelly battery is completely dead. Just have to wait and see.
George

Food for thought: In my limited experiences, any time two batteries are in parallel and one gets a little weak, the charging circuits will give more to the bad battery, in effect short charging the good one and later, making the good battery go bad while the weak one will keep puttering along. I have seen this over and over on vehicles with two batteries. I always replace both if one starts failing. Two cheap batteries that are matched will out perform a mixed pair if one is suspect.

Just my opinion and subject to be corrected.

I might add that the batteries of today and those of 30 40 years ago are not really comparing apple to apples either. Five years usage is pretty much all I get now on most any of them, no matter the application.

I've already came to the same conclusion. I plan
to remove the parallel connection while charging
and only use both batteries when I'm using the
dump trailer. I wire both batteries to truck or
tractor battery to charge when not dumping. Don't
plan to let batteries get completely drained when
using.

Now I'm going to experiment to see if the
batteryminder can do some good.

This has been my experience too. If one battery
tests bad, replace them all or you will be replacing
them soon anyway. Don't know why that is exactly,
but it holds true for me all the time. I had a
battery go bad on my truck just before the end of
the warranty, the other 3 tested fine, so they only
replaced the one. In only a few months I ended up
replacing all 4 at my expense because the warranty
had expired by then.

One big battery solves a lot of problems bought one from battery center called a Bus Battery had more CCA that 3 12 volts never had another battery problem

I think you are right about charging 2 batteries at
same time. The larger marine battery after being on
smart charger went to the desulfate mode, all cells
showed 3/4 charge with hydrometer. So I started
charger over in the 8 amp AGM mode. See what
happens later.