SLA Maintenance - Science vs BS?

I have a few different 12v Lead Acid batteries, mostly SLA AGM but a few old school FLA with the water caps.

Is there quick and simple guide to how to take care of these guys, that is based on science as opposed to marketing BS? Specifically about maintenance, reconditioning, desulfation / desulfating, or whatever you want to call it.

With NiCDs and NiMHs it is pretty straightforward -- memory effect, need to be charge cycled on occasion.

With Lithium it is also straightforward -- make sure you have an umbrella policy :lol:

With LA it is... not straightforward. And becomes even more confusing with wet, AGM, and "gel" batteries

Hehe... Don't often see "SLA" and "maintenance" in the same sentence? Maybe see also the word "oxymoron"?

Sorry. Might be "old school". But trying to keep up with the "younger generation". Last time I looked at lead-acid was for stationary cells (glass cases, and "heavy"...) used to store solar electric energy. :wink:

LockH said:

Sorry. Might be "old school". But trying to keep up with the "younger generation". Last time I looked at lead-acid was for stationary cells (glass cases, and "heavy"...) used to store solar electric energy. :wink:

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Very similar to my intended use case, plus I own 3 cars and a few other devices (uninterruptible power supply) that have regular 12v lead acid batteries.

This community seemed like the best source of research for how to take care of them. Or perhaps the best place to ask for a link to such a source



my e-bike project will certainly not have any lead in it.... well except maybe the paint

Once you get into sealed, then there really isn't any reconditioning or equalizing. I have some advanced lead chargers that have a crazy high voltage setting for desulphating, but it's only for refillables, and requires monitoring the specific gravity of the fluid and replacing what boils off. With AGM in particular the only way to extend the life is following the proper charging procedure.

Voltron said:

Once you get into sealed, then there really isn't any reconditioning or equalizing. I have some advanced lead chargers that have a crazy high voltage setting for desulphating, but it's only for refillables, and requires monitoring the specific gravity of the fluid and replacing what boils off. With AGM in particular the only way to extend the life is following the proper charging procedure.

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Any tips on an affordable charger that will do things properly?

Does the desulfating actually do anything? I know there are a few patents and some anecdotes, but peer-reviewed or otherwise professional studies proving it does work?

most maintenance issues with SLA can be done very fast: take them out of the device and bring them to the local recycling place for processing and buy a replacement lipo or lifepo4. you dont even need specialised equipemnt, just a car.

if that fails you can always go for a spearate charger, a higher spec CTEK charger is a solid choice. try looking for a MXS 5.0 for example.

but the most ideal case would be to have direct access to the cells. so you can hook up balance leads to the cells.

GeriatricGeoffrey said:

LockH said:

Sorry. Might be "old school". But trying to keep up with the "younger generation". Last time I looked at lead-acid was for stationary cells (glass cases, and "heavy"...) used to store solar electric energy. :wink:

Click to expand...

Very similar to my intended use case, plus I own 3 cars and a few other devices (uninterruptible power supply) that have regular 12v lead acid batteries.

This community seemed like the best source of research for how to take care of them. Or perhaps the best place to ask for a link to such a source

my e-bike project will certainly not have any lead in it.... well except maybe the paint

Click to expand...

Hehe... Last time checked, ONE manufacturer in China still makes lead-acid in glass cells.

Ebikes are like Glyphosate? Hehe

Desulphating definitely works in it's basic form, but most of the patented revive your battery stuff is hogwash. If you have a giant bank of batteries, or a golf cart fleet to keep running, or on a boat far from new batteries it's worth it. But for many, the time cost makes it worth it to just get a new battery. And again, it only works on flooded type.
For chargers, some have selector switches for the different types, and an equalizing setting, but they're not cheap. The cheap multi battery type usually has a profile that's safe for them all, but not optimised for each type, so it raises recharge times and subtly shortens the lifespans.

The most basic maintenance is to keep them charged to their normal full voltage, whatever it says on the label. Further you let it drop from that, the more sulfation that will happen, and the longer they sit the more permanent that becomes.

FLA maintenance is whatever the manufacturer recommends (because they dont' all make them exactly the same...so one brand's way may not have the same results on another brand). Mostly keeping it topped off at the right concentration of electrolyte, keeping terminals clean, etc.

SLA and Gel maintenance...there isnt really any. They're sealed, so anything you do inside that is going to break that seal, which is outside of the manufacturer expectations and recommendations. Some people have done stuff that revives dead ones, or refills boiled-off ones...but those come with no guarantee of success.




Sulfation itself...is sometimes reversible, and sometimes not. There's a number of ways people have used to do it, but I think it depends on what exactly happened inside the cell whether each different way actually works.

Sometimes crystals grow across and short between plates. SOmetimes a high current deforms a plate and makes it touch another one. Sometimes the sulfation is "hard" and doesnt' decrystalize. Etc.

There's lots of anecdotal stuff out there, and various sites that claim they have the true data on what happens and what to do about it (and each one has stuff that matches some results I've seen), but I don't know of any scientific-method research study that's publicly published with a definitive result.

Back in the daze of SLAs... motto was to "Charge Early and Charge Often"... to NOT leave any partly discharged batt to sit for any length of time. Always carried a charger with me, and always stopped beside an electrical outlet I could use. :wink:

I used the" get a really big battery and small solar cell and just use them up" method. Lasted 8 years. 4 trojan T-105's and a 60 watt solar cell through a 20 amp controller.

I would really appreciate any info on lithium replacement. Need 200 amp peak C to power purchased used 1000w full sine wave inverter not yet installed

Thanks

What voltage? 12, 24 or 48?

Back in the day we take the cap off we put a hydrometer in there and check for 1275 if it was too low that sell was dead but these days they can put pulses of high-voltage low amp or something like that to dissolve the sulfates on the plates it's all kinds of writings about it and probably a lot stuff that is pure junk. Whats the voltage ? Charge each one up if it get hot it's. Done

How old are they ?

they are ten years old and were even run quite dry. Never equalized. I'm running on a wheelchair battery now used when I got it.
Either you maintain them or not only kinda extends capacity life and not Chronological life. I chose to go with a high capacity and milk them down.
Maybe I should just go with 2 Trojan T-105's and a higher wattage solar cell.

I was also thinking of lithium because I could extend the life of the solar cell. I have the less efficient type that looses voltage sooner.

A 3s system of 3.7 volt nominal lithium and 12.6 max charge would be great if I didn't pull the voltage to inverter below LVD when pulling 200 amps surge. 100 amp nominal.

I am using a 400w mod. sine wave inverter and I had to pull the bonding screw on the AC wiring panel so that it would work.
Also batteries are in an inside closet that is not vented.