4-Amp Fully-Automatic Smart Car Battery Charger & Maintainer - 6V/12V Portable Automotive Charger with Temperature Compensation - AGM, Deep Cycle Battery Desulfator & Trickle Charger - Perfect for Cars, Motorcycles, RVs & Seasonal Vehicle Storage

Very Happy with This Purchase. On our 22-year-old Toyota, we revived a couple of years-old battery. We weren't sure if the problem was with the battery, the alternator, or something else. We tried the Manusage charger before spending money on a battery, knowing it would be useful to have for our other cars, especially when batteries "die" on winter days.Our battery tester produced no results. The dead battery was charged in a matter of hours after a simple hookup procedure. After reading other reviews, we assumed we'd need to keep it running at least overnight and into the next day. We expected to have to remove the battery and use the Repair mode, but we were fortunate this time.One overnight cycle took battery back to life, payed for itself!it worked once and error code came up and it never worked againThese are devices you plug into batteries that might be struggling or aren't used as frequently, such as a motorcycle battery during the winter. It's not going to jump a battery in anything bigger than a small car or 4-wheeler, but it can keep batteries from overcharging as a tender.At its current price of 60 I'd say it's a better deal than most of the others in its price point. The original price of 99 was too high. If I was going to drop 99, I'd get a NOCO Genius.I really had hoped this would be as simple as my Noco brand smart charger, but there was a little bit of a learning curve to use it. The manual could be better.Okay, so this review took me a while to put up because I had to read through the whole manual like three times and I was still a little nervous to use this because I've never used a device like this before. But, my Saturn ion has been refusing to turn over, and I was at first concerned maybe the charging feature didn't work or wasn't strong enough, so I took it to my neighbor's house and we tested it out on his truck and it worked just fine. And it does in fact diagnose accurately. I have theorized that my ion might have a alternator problem, because the battery is new as of like only a couple months ago, so still under warranty. The digital diagnosis is easy to read, and it does show that there's not an issue with my battery. And this little device is powerful enough that I almost got a crank out of the car when having it hooked up to my roommate's little Ford escort via jumper cables did nothing. So that definitely says something. All in all, as someone who is not an expert on cars, I think that this is definitely a handy thing to have but it has a learning curve. If you are really familiar with devices like this or with other similar handheld diagnostic devices or jumper devices, I would highly recommend it, I think that something this versatile is useful and definitely worth the price point. I got this as a part of the Amazon Vine program but I looked at it separately to see the price which I believe at the time that I ordered it was about $60? A friend of mine has just a plain battery jumper that is probably three times this size that takes up more trunk space and is more of a pain and it was like 65. So this is really compact, convenient for any size car, and it's definitely something that I would recommend if you're going to be investing in something to jump your car, it's smaller than your average set of Jumper cables, not that much more expensive than even a cheap set of Jumper cables, and about the same price as a heavy duty set, fits easily into any vehicle without taking up a lot of space or being Tangled and has the added bonus of not needing a second car, and also having a plain digital display to help diagnose the issue. Like I said if you're a car newbie and you're not particularly familiar with diagnostics those might not help you a whole lot, but if you read the manual carefully, it kind of helps you through that process as well.Honestly just for something that is versatile enough to jump anything from a 4-cylinder to a 12 cylinder vehicle including Marine vehicles and is water resistant, and as compact as it is, I would choose this basically any day over its competition.I meant to take pictures when I was doing the diagnosis on my ion but I got caught up trying actually work on the car and figure out the different functions of the device and consult the manual back and forth and forgot to. So I don't have any photos but I would definitely recommend it.This is great for batteries that don't get used often so that they don't completely discharge. It's good for seasonal equipment or second car or motorcycle. Batteries are very expensive, not to mention bad for the environment to just be thrown out. That makes this the most inexpensive item you can get