SLA battery recovery (?)

I’ve been doing the same thing and have seen good results after rehydrating and only a few days on the desulphator. One of the 3 year old 12V 7AH AGM I’m testing now actually read less than 1V initially and the smart charger wouldn’t even start a cycle. After popping the lid, rubber caps and adding a couple of ml of distilled water in each cell, it’s now able to hold over 12.5V and output almost 3Ah discharging through a Sam’s POB 35W HID as measured by a battery analyzer. I plan to leave it on the desulphator for a couple of weeks to see if it improves any more. While 40% capacity doesn’t sound that great, I’m hoping it will improve to over 50%, which is still quite usable for many small 12V applications. It’s definitely better than buying brand new batteries every couple of years when the UPS complains. To think of all the SLAs I could’ve saved and repurposed over the years!

KuoH

Got any pics or description of markings? Just because it says non-spillable doesn’t mean gel cell, it could be AGM and most can be easily rehydrated.

KuoH

I am following this with interest. I have a lot of SLA batteries that have gone dead from not being maintained. I have hesitated throwing them out because I am hoping that some day I will be able to revive them. I visited a battery shop in Sandusky, OH that had a whole array of DeSulfators going non stop, conditioning Lead
Acid batteries. I talked to the owner for some time about SLA’s and he claims he can reclaim them. He would drill holes in the top and add his “secret sauce”. Then on the the Desulfator.
I know enough to be skeptical, but not enough to discredit him. Still I have hope.



these are the 6 batteries I have:
http://www.ritarpower.com/upload/pdf/2013022710181068208411.pdf

Many times in my youth I couldn’t afford batteries but battery acid was available at all auto parts stores, CHEAP!
What a way to get an instant charge… and do roadside weed control at the same time.

“RT series is a general purpose battery with 5 years design life infloat service . It meets with IEC and JIS standards .With up-datedAGM valve regulated technology and high purity raw materials, theRT series battery has reliable standby service life.”

According to the specs, they’re AGM and from the google images I found they are the typical 12V 7/8/9 AH style batery. Just pop off the top plastic cover and you should find 6 rubber caps that can be removed to add water. There are widely different instructions on reviving them available, but no one has published a definitive guide on which is best and why. I chose what I thought was the least risky method, adding only a couple ml of water per cell, go through several slow recharge cycles letting the excess gas vent slowly until there was no more. Some of the more aggressive methods involve filling the cells to the top, then boiling off all the excess water and gas.

KuoH

I’ll be damned… Dry cells! :slight_smile:

Actually, they were maintaining a vacuum!

Now to get some distilled water. How long does water drinking water have to sit to be distilled?

Minerals don’t evaporate out of drinking water, if not become more concentrated.

Distilled water is sold at pharmacies for not much more than bottled water.

Forever if you just leave them in the bottle. I got a gallon jug of distilled water at my local grocery store for a buck or two. But do also hit the pharmacy isle and look for a small syringe to inject the water with. The holes in the battery are small and easy to vapor lock if you just try to pour the water in.

AGMs are not supposed to have any visible water level, that’s what makes them non-spillable. The fiber layers are supposed to be just moist enough to hold the electrolyte and allow for the chemical reactions.

KuoH

Great! Out of 6 cells I only need a reasonable service level from 3 to test the other components (motor and controller at 30 amps) before I splurge on a new set of cells (runtime is kind of important)

Thanks for the insight!

Any reason I don’t just fill it with electrolyte from the auto parts store?

That raises a question I’ve been wondering for a while - those cheap distilled water for drinking - are they really distilled?

Around here they’re priced very closely to filtered water and mineral water. How? I mean, distilling is a very expensive process. How can it maintain similar price against running tap water through a filter?

Makes me wonder if they’re real, and usable a such.

Anybody recommend a ready-to-use desulfator? Or a kit with everything needed to build? For just a single unit I'd really rather not have to go through sourcing all the individual parts.

You’ll have to do some reading to get the complete facts, but from what I understand, SLAs are manufactured with the proper amount of electrolyte for efficient chemical reactions and no excess byproducts. Adding more would just upset that balance, as would letting any leak out. I’m not sure whether it’s the oxygen, hydrogen or both that leaks as a result of overcharging, but adding only distilled water supposedly replenishes that.

As for the purity of store variety distilled water, I don’t know, but the label says the process includes reverse osmosis, distillation, microfiltration and ozonation. I guess I’m not too concerned given the price even if it can only eek out another year or two of useable battery life. Hopefully, it’ll be better than that.

KuoH

There are lots on ebay. I went with one of the cheap ones and I’m happy with it, though I’ve only been at this for a month or so. I figured it wasn’t much to lose if this was all just hogwash.

http://www.ebay.com/itm/Auto-Lead-Acid-Battery-Desulfator-12V-24V-36V-48V-Car-Boat-Forklift-Golf-/231356554456?pt=Battery_Chargers&hash=item35ddecdcd8

I also went with one of these battery analyzers to log what’s being put into and pulled out of the battery.

http://www.ebay.com/itm/Digital-60V-100A-Balance-Voltage-Battery-Power-Analyzer-RC-Watt-Meter-Checker-/400525712095?pt=Radio_Control_Parts_Accessories&hash=item5d41315adf#ht_4206wt_1218

KuoH

Some good information to read on Battery Sulfation before you buy a ton of desulfanators: BU-804b: Sulfation and How to Prevent it - Battery University

One video was saying that rainwater is a great source for distilled water. We’re getting plenty of that in the next few days!

Kids these days, I swear...

no it is not, it is full of particulate and dust and organic chemicals it picks up from the atmosphere

I'm going out on a limb here and guessing they are all toast and nothing you can do will make them worth doing anything more than recycling them .

4 volts sounds really really bad

I’ll pick some up tomorrow at Walgreens and see how it goes.

That little watt meter looks like just the ticket for doing some analysis. Just order the last one out of Cali. Hopefully have it in hand when I start testing.

kuoh, any idea what that 3-pin connector on the side is about?