Review on 🔋 Schumacher 15 Amp/3 Amp Fully Automatic Battery Charger and Maintainer for Marine and Automotive Batteries - 6V/12V by Nate Jenkins

I used this to charge my car battery after it ran out. I recommend reading the instructions, but they're pretty easy to use. Connect, first connect the positive pole, then the negative pole, then press the start button. The screen will show the current voltage and percent charge and should slowly increase. Eventually, however, the screen turns off because I suspect it's in sleep mode. You can turn the screen back on by pressing Start again, but don't trust the readings just yet. Mine got stuck at 80% after leaving the screen on for more than an hour. I eventually unplugged it and plugged it back in the next morning to test again and it was 96%. Also, the fan in the device turns on after a few minutes and runs about 90% of the time. It's pretty loud. It cannot jump on your car. I didn't see it advertised anywhere so it's not a disappointment but some reviews said they saw it in an ad and were pissed it wasn't there. I've only used it once, so I can't comment. to its longevity, but my battery drained like a nail to 96% with no issues.