6V/12V 4A Automatic Smart Battery Charger Maintainer with Cable Clamps Smart Repair Charger for Car Boat Lawn Mower Sealed Lead Acid Battery Repair Battery

I had a Schumacher battery charger that would report that my battery was 'bad' and needed replaced after after running for a while. The battery had sat in a riding mower for a couple of years and was nearly completely dead. The battery was 4 years old so I figured it did need replaced. I bought this charger because I wanted to compare. This battery charger had a much more informative display. It showed the battery was nearly completely dead. I held down the 'repair' button on the charger until it started the repair cycle and went in the house. Next morning I came out and the display said 'full'. I couldn't believe it. The 80's craftsman tractor mower has a twin cylinder, and it cranked perfectly. Had I trusted the Schumacher battery charger, I would be buying a new battery. I wish I would have known that my old battery charger was costing me money, I would have replaced it years ago. I plan to buy another one of these because I have plenty of batteries around the barn and in trucks that sometimes need charging.

Works fine, unless the battery voltage drops below 8 volts. Then it thinks you are on a 6 volt battery and will not charge. other than that, works fine.

Lohotek - Model R12-US The following is my experience with using this charger to repair a car battery that had been allowed to sit up for several months, was deeply discharged and would not take a proper charge by normal means. The starting voltage of my deeply discharged car battery was around 2.1v. I had to "trick" the charger into starting its charge cycle by using jumper cables connected from a good battery to the discharged battery to convince the charger into believing it was connected to a serviceable 12v battery. Before I did that, the charger thought it was connected to a 6v motorcycle battery because the voltage was below 6v. There is a "Mode" button that should manually change between 6v and 12v without the need to resort to such trickery, but apparently, this button will only change between "Motor Cycle" battery and "Car" battery, and even then, the button only works -before- you plug in the A.C. power and not afterward. It took me a while to figure that one out. At first I thought the Mode button did absolutely nothing since I was trying to change the mode while it was plugged in, which is impossible. This is very puzzling behavior because the most practical use for such a button would be to change between 6v and 12v and not "Motor Cycle" battery and "Car" battery. The Chinglish manual holds no answers (big surprise), but I read somewhere on the Internet that the button wasn't used because the charger chose the battery voltage and type automatically. This would be great and all, except for the fact that the charger often gets it wrong when a battery has been badly depleted, and guess what? You usually need to use a battery charger when a battery has been badly depleted!!! Grrr. The manual also doesn't tell what, if any, practical value there is to changing between "Motor Cycle" battery and "Car" battery. I can only assume that the charge cycle is longer and/or more aggressive, or more likely done at a higher amperage level for a "Car" battery than it would be for a "Motor Cycle" battery. This is because a car battery is larger and can therefor withstand a higher amperage level without overheating. Would the makers of this charger care to leave a comment and enlighten us all as to what this setting actually does in practical terms? After charging the battery for a couple of hours, I was able to then disconnect the charger, reconnect the charger, and then start the "Repair" cycle. After charging for a couple of hours, the battery was finally at a high enough voltage to be detected as a 12v battery instead of a 6v battery. The meter on the charger says "PUL" for "Pulse" when it enters the repair cycle. This "repair" cycle is really just a Desulphator or Desulfator (Both spellings are common on the Internet) cycle that uses pulsed electrical charges to try to clean off the plates so that they will take a proper charge from then on. Variations on this technology have been around for decades now but it is surprising how few battery charges sold today have this very useful function built in, especially at this low price range. It took nearly 24 hours for the charger to complete the "Repair" cycle. It took about 8 hours to get past the first bar, then it took the next 8 hours to reach 4 bars and then it took about the next 7-8 hours to finish the 5th and final bar and to be fully charged/repaired. After the light came on indicating it was fully charged, the internal voltage meter in the charger fluctuated between 13.0 and 13.1v, but mostly stayed at 13.1v. My good test meter read 13.11v so I know that the internal voltage meter is accurate to within very close to 1/10th of a volt, which I would consider adequate for a device such as this. The following is a log of the charge levels that I recorded for 10 days, without the battery connected to anything, to prove whether or not the battery was actually repaired or whether it would quickly self-discharge in a few days. All voltage readings were taken with the internal voltage meter with the charger unplugged. If anyone tries to replicate this test, make sure to not leave the meter connected in between tests as it is constantly drawing power all the time it is connected. Day 1 = 13.1v Day 2 = 13v Day 3 = 12.9v Day 4 = 12.8v Day 5 = 12.8v Day 6 = 12.8v Day 7 = 12.7v Day 8 = 12.7v Day 9 = 12.7v Day 10 = 12.7v A fully charged, good 12v battery will read 12.6v with no load attached. As you can see, once most of the "surface charge" is removed, the battery settles down to close to its true charge level at 12.7v, which indicates that it only has .1v of surface charge left in it. After being allowed to sit for 10 days and still have some surface charge, I am confident that this battery has been properly charged and repaired. You can also remove the surface charge by running a heavy load on the battery for a few minutes, such as running your car headlights until the battery reaches 12.6v. It's not very healthy for the battery to keep its surface charge for a prolonged period of time so this is probably the best practice if the battery will be stored for a period of time. I only left the surface charge on this battery as a test and I would not recommend anyone to do this normally as it is not good for the battery and will shorten its life. Conclusion: Since I've only had this charger for a short time, it is too early to tell how long it might last, but as it currently stands, this seems to be a really good charger for the relatively low price for which it is currently selling. I paid 30 for it here, but I have seen it as low as 25. I am removing 1 star for the mode button that does not allow you to manually change from 6v to 12v like most other battery chargers would allow. This is a great inconvenience to have to find a good battery to trick it into believing it is connected to a 12v battery when dealing with a very deeply discharged battery. I'm also displeased with the poorly translated and incomplete English manual. Even though poorly translated Chinglish manuals are par for the course these days, I still find it unacceptable since it could be so easily remedied by simply having a native English speaker proof read and correct at least the most egregious mistakes.

I have no idea if this thing is broken or just doesn’t have a viable function. READ THE PRODUCT DESCRIPTION CAREFULLY, maybe that’s where I erred. Every battery I place this on causes a fault with the unit. If you put it on a charged battery it will not fault but after a few moments reveal “FULL” tell me something I don’t know.

With heavy duty clamps and easy to use guage, this is a quality product for charging a battery. I use it for my John Deere rider mower during the offseason or winter.

It came defective so I returned it and order a different one.

I thought I'd be able to use this to bring my old car battery up to snuff. Apparently this is only good to help maintain a battery that has no problems. I'm sure this would be good for somebody but it's just no good for me.

I bought this charge to charge my mom car battery, she drives short distance daily basic, this is not good for the battery, the driving time is not long enough to charge the battery, she kills the battery ever 2 to 3 years. I planning to use this charger to charge her battery monthly to hope it keep the battery life longer. I used it once today on her card, it took 8 hours to fully charge.