12 Volts Lead Acid Battery Maintainer & Desulfator Assembled Kit Repair

I had a car in my garage for over a year without being started, including one winter in northern Ohio. When I finally had the repairs nearly done I checked the battery and it was reading less than one volt and it wouldn't accept a charge.I knew what desulfators were and bought this one because it was cheap. Mounted it on a wood scrap and hooked it up along with a trickle charger: had to use the trickle charge 'cause the thing takes its' power from the battery it's hooked up to.At any rate, the condition of the battery began improving after several days as judged by increasing battery voltage to several volts. Left it connected about ten days when the battery voltage was up to around 9 volts at which point I switched from the trickle charger to a more powerful 3 amp 12 v charger.After being connected about three weeks I measured the battery voltage again (as I'd been doing twice a day since the start) and found the 1/2 hr after disconnecting the charger the battery was measuring the proper 12.6 volts. At that point I turned the car lights on for about ten minutes and then started the car without problems. Did this several more times over the next 30 minutes without any issues.Looks to me like this little device saved me about $150 or more ...

I used this on around 3-4 batteries that were used in hybrid vehicles. I because these batteries were not put under heavy load, I did a heavy charge, then discharge, then charged again, and then put this device on until it was down to around 11.4 volts. Repeated 3 times and every one of the batteries recovered. The 4th battery was below 10 volts, so I would charge it up and put this device on it before it bleadoff to 10.4 then 10.8 then finally 11.4.All in all 4 batteries came out ok. I had to add a fuse and diode as I almost connected it by accident backwards a few times.

What a disappointment! I have several of these that were purchased from different vendors; but, with the same PC board, same circuit and same components (quality of components - I don't know) but what a puny pulse!Using the same battery under the same conditions, the other units produce a positive-going spike at around 2kHz that varies in amplitude from 7 to 9 volts above the battery level (in my case, about 12.6v.) barely produces 1 VOLT. The battery used for testing was a small lawnmower type, connected to nothing else for the comparison.I may try to find out what's wrong with it if I find the time... guess I can't complain since the seller doesn't actually give a minumum pulse height. Probably crappy inductors or maybe a cheapo, P-channel FET.You might compare this to pill containing less than 20% of the typical life-saving active ingredient. I certainly wouldn't use it to protect a battery I depended on from sulfating.My advice: DO NOT DEPEND ON THIS POS TO PROTECT YOU.

Restored an older car battery I was about to give up on and send in as a trade-in battery core. So glad I tried this as a Hail Mary attempt to get it back up. The old battery held 8.5 volts, after 3 separate overnight attempts to trickle-charge with a 2Amp charger plus this desulfator connected in parallel. After the 4th night's charging session, the old battery maintained 11.7 volts before hooking it up for the 5th night. I'm going to let the old battery sit for several days after the 5th session, and if it holds 11.7 volts or better, I'm sold.One caveat: As another reviewer pointed out, this device KILLS FUSES, so be sure to have a supply of 20mm fuses. I use 250v, 3A fast-blow fuses, and have gone through 3 fuses in total. (I didn't read the original fuse's specs, and these are what I happen to have in stock).I'm tempted to just install a similar-rated thermal resistor as a permanent solution if the old battery I'm working on holds its "good charge".

Tried it on a AGM gel cell and saw no improvement on the battery, still low voltage. Haven't tried it on a lead acid battery without the gel feature.

So I put a scope on the battery terminals while this was running. It makes a series of very short chrips in to the battery that ring at around 10mhz, which I guess there's some fundamental frequency in lead acid batteries at 12 mhz, which could be snake oil, but at least everybody's drinking the same kool-aid. The voltage of the pulses only manages to increase the voltage on the entire battery by 5V, so a little under 1V per cell. Crappier batteries may well have a higher impedance, so your voltage might be a lot more. That's not a good thing.Worst case, you have a cute little blue LED for your battery that will explode a fuse if you reverse the polarity. That's the reverse polarity protection - A diode will short the input and the fuse will pop, which is preferable to smoke and fire. I don't know if I'd get the case version or not. I'm not a big fan of leaving the bare PCB hanging out near the batteries, nor am I cool with leaving a metal box anywhere near the wiring. I put alligator clips on my two units and just connect them during long term storage.

This desultor worked great. My car battery wouldn't hold a charge. The charger would shut off indicating the battery was fully charged. I'd turn the key, full instrument panel lights would come on, and as soon as I put a load on the battery by trying to crank the engine, the battery would act as if it were disconnected. Everything would go dark, and not so much as a click when I turned the key. I hooked this desultory to my battery for two days while connected to a charger, and the next time I tried cranking the engine, it started the car. I've bought several more of these and absolutely love how strong my vehicles start now. My diesel truck batteries were holding about 11.8v to 12.1v before, and now they both hold at about 12.2v to 12.4.