I have an Optima AGM deep cycle battery that is taking a charge but not holding it. From what I read I might be able to bring it back with a battery charger with desulfate feature. Does anybody have any experience with this good or bad? If good what worked for you. TIA

 

Desulfation has been around for a few years in a few forms. The current technology works by applying very high frequency pulses of voltage to dissolve the lead sulfate crystals. The former technology used high voltage pulses that accomplished desulfation but damaged the battery over time.

Some chargers have a desulfation step that activates every time the charger is activated. It stops as soon as there is zero sulfation. I have a three CTEK chargers that do this. On a good battery the CTEK desulfation step lasts less than a second.

I've used the oldest of these chargers for about 10 years on a single battery and the battery still works fine. So, I can say that the CTEK desulfation step does not appear to harm the battery.

And the theoretical basis appears correct to accomplish desulfation but I don't have specific experience with using CTEK on a sulfated battery.

 

I bought a Pulse Tech XTREME CHARGE XC100-P on a recommendation from a co-worker. I have been using it as a maintainer so as yet I have no experience with recovering a battery with it, but my co-worker said he has recovered a couple.

https://www.impactbattery.com/pulset...r-xc100-p.html

 

I will probably buy one of the ones suggested just because I need a maintainer anyways. I read on another forum that I may be able to revive my battery some just by running it down to 11.5v then recharge it a few times. I did that this weekend six times and it does appear to have worked some. Right now my battery takes a full charge but quickly drops down to 12.45v before it was dropping down 12.31v. I will probably try that a few more times and see if it keeps improving. If I can get it to 12.6 I should be good.

 

Deep discharge and recharge cycles are the major factor in reducing battery life. Don't do the discharge-recharge program.

What deep discharge-recharge does is to mix the acid in the cells. Old batteries tend to accumulate a greater concentration of acid at the bottom of the cell, which reduces battery capacity.

Modern chargers, such as CTEK, have a program to mix acid in wet batteries. It's done with a short, controlled overcharge to produce gassing. The bubbles mix the acid without such a severe reduction in battery life as doing the mixing with deep discharge-recharge.

These comments only apply to wet batteries. If you buy an AGM battery, they do not have a need to ever mix acid. And they last longer because they are much more resistant to deep discharge-charge degradation. As an example, the Odyssey AGM in my Challenger is 11 years old (80,000 miles).

But most AGMs do require a higher charge voltage than a wet battery, so review the charger you will be buying to make sure it has a charge profile for AGM as well as for wet batteries.

 

Thanks for the info. My battery is an Optima Yellow top deep cycle AGM battery and my charger has an AGM setting. The discharge recharge cycles were mentioned by an Optima rep specifically regarding Yellow top deep cycle AGM batteries like the one I have. Are you saying that AGM batteries don’t sulfate, or that they can’t be desulfated with these chargers?

 

Joel, I apologize, I blew by the part about your having an AGM battery. Yes, take the advice of the battery rep. Yellowtops are made for charge-discharge.
Gary

 

No worries Gary, I breeze right past pertinent info on posts all the time too. I have done around 15 discharge cycles and it appears to be getting better every time. I am now holding a charge at 12.58v. I will probably do a few more as long as the numbers keep
going up. I would like it to be at least 12.6 but it would be nice if I could
get it up to 12.8 or more.