Are my lead acid batteries damaged?

Try trickle charging them over a period of days. I would run an equalization charge as well but sometimes the slow-&-low will be enough.

HOW are you charging them? With what kind of apparatus? Some "smart" converter chargers are so stupid they couldn't find their --- with both hands.

Okay. . .the batteries are two 12's in parallel.
My gosh, they are heavy. . .about 60 pounds each.

Label on battery says they are Deep Cycle RV/Marine - Interstate Batteries
30-month pro-rated.

They've been charging for two days. . .the camper meter said 13.1 volt this morning.
They started charging at 13.4 volts two days ago.

I took both batteries out and separated them.
No wait time.
Checked voltage - both batteries had an identical 13.02 volt reading.

Checked specific gravity in each cell with a cheapie battery hydrometer.
Cell readings are between 50-percent and 75-percent.

It appears the batteries are nearing the end of their useful life from my point of view.
Opinions?

Thicker is better. Like when someone is shooting at you.

If they are deep cycle you have lost a bit of life.. Not enough to really notice.

If they are Marine/Deep cycle.. I'd try recharging but no guarantees

If they are Starting batteries.... Prepare for the worst.

This is one of the reasons I prefer six volt pairs over 12 volt. The most common six volt is a DEEP CYCLE.. Though you can get true DEEP CYCLE 12 volt.. They are not easy to find or easy to pay for.

They are two 12's in parallel.
I'll remove the camper cover and pull the batteries tomorrow to have a look and test with a hydrometer.

They should be fully charged by then.

X2 MEX

Without TESTING them, you'll need a gypsy and an Ouija board to determine if they have lost too much to bear the brunt of another trip. Who knows how much was "left" to begin with after 5 years of service before they endured a full-pack 20 mile forced march?

A hydrometer check will reveal any cloudiness, smoky color in the electrolyte after the batteries have been "fully recharged". That and acid density inequality.

Then a full load 1/2 of CCA rating discharge should be performed. If the voltage droops to 9.6 or below, that alone is enough to give them the last rites.

1. Electrolyte density
2. Electrolyte color and clarity
3. 1/2 CCA load test for 15 seconds.

I have 4 6 volts with a May-05 sticker on each one....Still going strong. I'd charge & see.

RichieC wrote:
The two lead acid batteries in my truck camper were down to 11.7 volts when I returned from a two months travel.

The AC power to the camper went out (GFI tripped by the gardner) sometime during my absence.
So no charge.

The batteries are 2008 - five years old.

Do you think that they are compromised for sure and should be replaced?
Or wait and see. . .maybe I can get another couple of years out of them?

Rich,

I'd recharge them and wait and see. 11.7 isn't that bad. If they got there slowly and didn't sit there real long, they are probably no worse off than any other five year old batteries.

You say batteries.....
Are they 12s in parallel or 6s in series?
If they are 12s, break them apart and recharge them separately. Yes, there is a reason for this. Lead/Acid batteries do not play well together and the one with the lower internal resistance will increase its density before the other can draw on the charger enough and only one will come up to full density.

Matt