De-Sulfating Chargers safe for Electronics?

[dickfoster]

What I've always wondered is if AGM batteries need desulfating. Or does it work with AGM batteries if you try. And then where's the proof of course.

I sulphated two AGM batteries at the same time though my own neglect by letting the truck sit unused for long periods of time then driving it only a short distance, maybe 10 or 12 blocks then letting it sit again. After repeated abuse and neglect both batteries got to the point that neither would hold a charge, yes they became sulphated as any lead acid battery can.
I then bought two new batteries and recovered both of the old ones with a pulsing/ desulphating charger. It took several weeks. Now both of the old batteries are as good as new. Any battery can be abused and ruined though neglect, AGM or otherwise.
To prevent future battery problems I installed a solar panel and charge controller in the truck for when it's parked outside and plug it into a desulphating maintenance charger when it's parked in the garage where it spends most of it's time now.

 

[dickfoster]

Same principle in AGM and same "science"'to back it up...
AGM uses the same type of plates...it's the material between the plates that is different-absorbed glass mats vs liquid.

This is 100% correct. If it's a lead acid battery of any kind it can and will suffer the same malady if neglected as the chemistry is the same. AGM batteries usually have more lead of a higher purity. This is because the lead does not need to be alloyed for rigidity so as to support themselves as the plates in a common wet cell do.

 

[Fallon]

Desulfication is the slight overcharge of the battery to try and remove material from the plates. This process is fine for most electronics. It's only a few tenths of a volt over normal charge (13.4-13.6v) and most "12v" systems work from about 10.5v - 14.5v ish.

Sleep well! No worries! If you still can't unhook the battery terminals- it will take about 2'.

No, that is not how it works at all. Lead sulfide crystals (along with most anything) have a resonance frequency. Hit something at or make it vibrate at that frequency & they shatter. I'm not sure if a DC pulse or AC is used, but it's applied at the resonance frequency of lead sulfide. It takes a while, but it will usually remove the lead sulfide. Desulfating is usually done in combination with a trickle charge.

Hitting a battery with high voltage will boil off electrolyte & kill it. There is a lot of science on what voltage to use at what stage. Higher voltage (14v or so) at the bulk charge stage is fine. 13.5v at the trickle charge maintenance stage could boil it.

The RV BATTERY CHARGING PUZZLE << HandyBob's Blog is a great place to learn about battery charging & solar. A little angry & ranty at times, but he knows his stuff.

 

[Industrial Toys]

I came across this interesting article today.

Battery Desulphation


Apparently it states that if the pulses are strong enough (in amplitude) to do any good, damage to equipment can occur.

I still think that fifty cents of chinese electronics sold for forty dollars American, is just a rip off. I have many, many batteries. I wish it was that cheap and easy!

 

[RNeumann]

No, that is not how it works at all. Lead sulfide crystals (along with most anything) have a resonance frequency. Hit something at or make it vibrate at that frequency & they shatter. I'm not sure if a DC pulse or AC is used, but it's applied at the resonance frequency of lead sulfide. It takes a while, but it will usually remove the lead sulfide. Desulfating is usually done in combination with a trickle charge.

Hitting a battery with high voltage will boil off electrolyte & kill it. There is a lot of science on what voltage to use at what stage. Higher voltage (14v or so) at the bulk charge stage is fine. 13.5v at the trickle charge maintenance stage could boil it.

The RV BATTERY CHARGING PUZZLE << HandyBob's Blog is a great place to learn about battery charging & solar. A little angry & ranty at times, but he knows his stuff.

I appreciate the confidence! The pulses can be up to 60v. The frequency depends on the company and the patent. You could "see" the pulses with a oscilloscope but with a "normal" volt meter like a Fluke or some other brand it would show a slightly more voltage. This is why the OP said the manufacture instructions say it's "safe" to leave the battery hooked up as most devices aren't sensitive enough to be affected by the pulses.

One could also look up battery equalization. Another, all be it, "dumber" way to improve or maintain batteries. I don't think anyone was suggesting hammering a battery to the point it would boil out or over heat.

Answer To The Question: Battery Desulfators - Do They Work? - Blog

 

[RNeumann]

This is 100% correct. If it's a lead acid battery of any kind it can and will suffer the same malady if neglected as the chemistry is the same. AGM batteries usually have more lead of a higher purity. This is because the lead does not need to be alloyed for rigidity so as to support themselves as the plates in a common wet cell do.

Good point about higher lead content in AGMs. Hadn't thought about that but it makes sense.

 

[txndncowboy]

I've had 2 de-sulfating maintenance chargers for 30 if not more years. One finally went south on me a few years ago and took the battery with it. Was I mad? At first yes since it was my motorcycle and was going to go ride when I discovered it. But after I came back to my senses I wasn't. That thing saved me at least 10 batteries in it's life. I was only able to get 3 years at most out of a battery before getting those 2. I never new if that de-sulfating worked until I tried it on a battery that it was never ever on and wouldn't hold a charge. I got 2 more years out of a dead battery. Might have got more but that puppy was truly neglected. Adding water was the last thing I every looked at on that thing. So I was pleased as punch to get any more use at all out of it. Let alone 2 years. I bought 2 more of those little things as a result. They are money well spent.

 

[dickfoster]

I appreciate the confidence! The pulses can be up to 60v. The frequency depends on the company and the patent. You could "see" the pulses with a oscilloscope but with a "normal" volt meter like a Fluke or some other brand it would show a slightly more voltage. This is why the OP said the manufacture instructions say it's "safe" to leave the battery hooked up as most devices aren't sensitive enough to be affected by the pulses.

One could also look up battery equalization. Another, all be it, "dumber" way to improve or maintain batteries. I don't think anyone was suggesting hammering a battery to the point it would boil out or over heat.

Answer To The Question: Battery Desulfators - Do They Work? - Blog

I've actually connected a good high speed scope to mine and did not see much. Of course, I used AC coupling, but the low impedance of the battery pretty much gobbles up the pulses so there isn't much left to see on a scope.

 

[Fallon]

One could also look up battery equalization. Another, all be it, "dumber" way to improve or maintain batteries. I don't think anyone was suggesting hammering a battery to the point it would boil out or over heat.

Equalizing is a very different process. Basically it boils your battery. Normally not a good thing, but it has its uses. Sitting around water & acid in a lead acid battery (don't think it's relevant to AGM or gell cell batteries & can blow them up) can separate so you end up with a layer of acid floating over or under (forget which) a layer of water. Not good for its ability to hold a charge or survive cold. Equalizing/boiling for a very short time mixes things back up.

I'm guessing the boiling action might knock some lead sulfide off the plates, but wouldn't count on it.