Battery Desulfation, Does It Work?

[lapeer20m]

The alternator gave up the ghost in my snow car, a 1990 eagle talon tsi awd. I was just too busy with other things, so it sat with a dead battery for a couple of weeks. I finally got an alternator installed only to find that my battery is now junk. She'll start with a jump and run just fine. If i shut her off, she won't start again. Tested the alternator, and it is definitely working.

I bought this charger a few years ago. It's the best battery charger i've ever had, and i absolutely love it! It's started a bus with a dead battery many times, also powers all my 12 volt appliances when i'm parked at a party.....i digress.

This fancy charger has "desulfate" mode. the original directions are long gone, but were written poorly in chinese to english conversion anyhow.

I started the desulfate yesterday evening, and it'll run until tomorrow morning...so for at least 36 hours.

Anyone think this will work, or have any experience with battery desulfation. I wonder if this concept is just snake oil? I figure the battery in the talon is junk anyhow, so this can't hurt.

If it seems promising, i'd like to find another "junk" battery or two and do a little scientific test. Maybe charge the battery and see how long it will run a particular device like a 100 watt light bulb. Then desulfate, charge, and see if things improve.

 

[bbbrt76]

there are many desulfation techniques that will return the function of a sulfated battery, the problem is that most dead batteries are not due to sulfation, although your description does indicate that yours could be, and all desulfation techniques remove material from the plates, reducing capacity and battery life, which if the battery is useless anyway then no big deal, the following is copied from an electric vehicle forum I frequent and is their usual recommendation for attempting to save lead acid batteries that have been left dead for a long time


Since they were very dead, a normal charging regimen will not recover
very much capacity. The cells will be seriously out of balance (some
half charged, some totally dead).

You should apply a higher-than-normal voltage (16-24v) through a
resistor that limits current to about 1% of the battery's rated amphour
capacity (1 amp for a 100 amphour battery).

Check the current occasionally. It should start low, gradually increase,
reach a peak, and then falls again. Leave it on until the current passes
its peak and has stopped falling. This may take hours, or even days!

At that point, disconnect the charger, and let the battery rest 8-24
hours. The voltage should be in the normal "charged" range, 12.5-13v.
Remove this temporary charger, and finish chargeing it with a normal
charger such as you described. If the battery has recovered, it should
behave relatively normally.

You'll then need to cycle the battery a few times. Discharge it to
10.5v, measure the amps and time, and multiply them together to get
amphours. Recharge it using your normal charger. Discharge it again, and
see if you get more amphours. Repeat as long as the amphours keep
increasing by a significant amount on each cycle.