HULKMAN Sigma 1 Car Battery Charger - 1A 6V/12V Automatic Smart Trickle Charger, Battery Maintainer, and Desulfator with Intelligent Interface

Due to long periods of neglect my battery went to levels I didn't know were possible (3.7v). So, it came down to the point where a jump-start was required every single time I shut off my car as that would jolt the voltage high enough to switch over to my 2 aux batteries, with the length of time increasing every time.The 'repair' function didn't do anything other than beep and tell me the battery is funked, but did raise the voltage to 5.29v although it took 48-51 hrs. On the bright side, it seemed to stop drawing power to attempt charging once it threw up the warning of not holding a charge, but drew enough power to beep until the end of time. So, that's a cool feature. At least it seems to know when it's doing something that is inefficiently working, where any continuation won't do anyone any good and stop itself. "smart" charger for sure.Since the intended use for this product it's low-amp trickle charging and not the "repair" mode, I popped off the battery caps and refilled each one with distilled water mixed with a dash of epsom salt, clamped the correct battery posts, set mode to normal (the first one), confirmed current output (~1.5A) from power source, and prayed that this works or look stubbornly stupid.A day and a half later, the battery measured 12.1v.More importantly, even though there's some hesitation, the car turns on by itself!After charging 2-3 times overnight, the battery seems fully grown (12.9v) and has had no problems turning over with voltage holding around 14.1-14.3 , occasionally dropping to as low as 13.5 if I'm running electronics that suck a lot like headlights, the sound system, 10A charger for generator, 2A charger for phone, etcBut even when put under that much stress at any speed, there's no headlights dimming, car rumbling down, head banging on steering wheel so yahtzee! it works!I'm not sure if this speaks to the quality of the charger or the battery for bringing it back from the point most people (including the 'repair mode' message) would buy a new battery-which isn't wrong by any means.I would've bought a new battery myself if I didn't have to choose between that and food. Damn cheese is expensive.But thanks to the quality products offered by HULKMAN and battery by Dyno (yay USA), you made it possible for me to have my cake and eat it too. Even though there are countless other companies that I could've chosen, it seems I made the right call choosing you [pikachu]!Thanks HULKMAN (somewhere on earth, probably China) and Dyno Battery (Seattle, WA).

This trickle charger has saved my almost 7 year old optima yellow top battery that had depleted to 8.4 volts! I first tried the 12v agm charge after 2hrs it said battery bad, then tried 12v repair, again after 2 hrs said battery bad. So said to myself why not try repair one more time if it stops in 2hrs (which it did and said bad battery) i would have the full 4hrs total of repair mode. After the failed repair mode attempts i put it on 12v agm again and this time i stopped charging at 8hrs and at 12.2v and did repair mode again. This time it did the full 4hrs but at the end said bad battery. I put on 12v agm and let it charge 24hrs to 12.8v and tried repair mode again and finally it did not say bad battery! I put it on 12v agm to full charge, took another 18hrs. After fully charged i did another repair mode. Picture is 8hrs off the charger. My optima holds a charge for at least a week!(how long its been) Time and time again i have heard trickle charge to save old depleted and solfated batterys is the only way, i think the 32ah rating for this charger is under rated and is for thoughs who dont understand battery charging do's and do not's, safty, and things to keep an eye on, and also that trickle charging can and will take a long time. I have put this thing to the test and it performed flawless and exceded my expectations of saving an optima yellow top and is a grate tool in my garage. Not only did it save my yellow top but also saved my riding lawnmower battery as well, along with charged up my 65ah motorcraft battery, with prices of batteries these days it has saved me 10 times the amount i paid for it and is a must have! I also have the Hulkman 85 jump pack, i used on the optima yellow top to start my 6.8L v10 ford 350 several times. Do wish the sigma 1 charger manual had more info in it, that is something i hope hulkman addresses, but its nothing google cant help with. Do keep in mind this is a 9 month ownership review. I do expect these products to last a long time with the grate quality and experience i have had. Hulkman is a grate company with great quality products!

I leave this attached to my AGM while the car sits in the garage over winter. It performs an initial conditioning then maintains voltage at 13.5 volts. Its a really nice design, and I trust the computer settings within it. My battery will not overcharge.I initially purchased it when my previous AGM battery died during our sever cold spell last winter. It was too far gone. The HULKMAN could not bring it back. But now I keep my new battery charged and believe it can work with batteries that are degraded, but no fully dead batteries.