Bad Battery - Good Battery !!! ???

[Rbertalotto]

So I bought a used Pop up Truck Camper. And it came with a deep cycle battery that was bought two years ago. The battery LOOKED like new.

But it was totally discharged.

I hooked up my Super Duper, computer controlled battery charger maintainer that I bought from Sears last year:



After being on this charger for a few hours, the charger then said "BAD". This means the battery is dead. But it did have 11.6 volts when I checked it with a digital volt meter.

So I did what I've done before. I hooked up my old "Sportsman 10" battery charger (1972 era ) and set the timer for 4 hours @ 10 amps.



I then checked the voltage.....12.8V...!!

I disconnected it and left it for two days. Checked voltage again and it was 12.7V.

I hooked it back up to the Sears "Super Duper" and it went up to 13.3V and then went into the maintain mode. No BAD indication.

So what do you think, did I "save" this battery?

 

[wrcsixeight]

The battery lost some capacity. You will have to see how it performs under load to know how much capacity it lost.
Proper full charge voltage does not indicate capacity loss. It indicates that no cell is shorted.

An aged or abused battery is like a gas tank which just keeps getting smaller. You can still fill it up, it just takes less to do so, and has less to give afterward.

 

[Rbertalotto]

Thanks.......I'll keep an eye on it and see how it goes.

 

[G35Vortec454]

My suggestion is charge it at a very low rate, say 2 amps on manual, for a week.

 

[dr350jja]

Think it's time to get rid of the Super Duper, computer controlled battery charger maintainer!

 

[4x4junkie]

^^
What they said.

A discharged battery rapidly builds up lead sulphate on the plates. It can still read full voltage, but will drop very rapidly with any load put on it. You could still get lucky though and get some use out of it if it didn't sit like that for too long.

 

[bj70_guy]

Have it load tested.

 

[Rbertalotto]

One of the battery chargers I have (Optimate) has a "desulphate" function where I believe it cycles the battery with reversed polarity very rapidly and "shakes" the sulphate off. I know it has "saved" a few motorcycle batteries for me.

But I wasn't sure what type of Deep Cycle battery I have.

Do AGM batteries have "plates" that can sulphate?

 

[4RunAmok]

All of the typical automotive batteries have lead plates. AGM is just a type of lead-acid elctrolyte, Wet cell vs Dry cell vs Absorbed Glass Mat.

 

[wrcsixeight]

Manual chargers are almost a necessity in trying to restore as much battery capacity as possible. The longer they are left on, the higher the voltage rises the higher the temp rises, and the more likely the plate occluding sulfates will be reabsorbed into the electrolyte.

With flooded batteries a temp compensated hydrometer should be considered a necessary tool when applying equalization voltages. When the specific gravity stops rising, or battery cell temp exceeds 115F, stop the charge cycle. Do not try equalization charges on AGM batteries, though Lifeline has a specific 'Conditioning' procedure which is similar.

Automatic chargers are not these magic super duper magical battery restorers despite their claims and the claims of those justifying their purchases. Pulse desulfation chargers are considered pure hokum by many.

While one can often get more life out of an abused battery by manual equilization charges or pressing the "magical" desulfate button on an automatic charger, restoring one to near new capacity is simply not going to happen.

You can't counteract battery neglect and abuse, and battery abuse can defined as a heavy prolonged discharge.

 

[highdesertranger]

has anybody tried epsom salt to desulfate or is this just a urban myth. highdesertranger

 

[LR Max]

My suggestion is charge it at a very low rate, say 2 amps on manual, for a week.

X2. 2 amp trickle charge ******. I've done it multiple times on my Optimas and extended their lives by years. However you need to realize that in a year or two it'll need to be replaced.

 

[Rbertalotto]

Im the OP on this thread...........

I have now had the battery charged with a full 10amp charger. Then I put the battery back into the camper and hooked it to the inverter for a day. Finally I had it on a Deltran Battery Tender for a couple days.

I disconnected it and read the voltage at 12.9V..........three days later it is at 12.9V........I used the lights in the camper for a few hours and the voltage went to 12.1V, hooked it back up to the Deltran and it went up quite rapidly to 12.9 again. Disconnected it for two days and it is still at 12.9.

Seems I've "Saved" this battery............We'll see!