Review on ABLY Car Battery Charger: 12V/8A 24V/4A Automatic Smart Charger with LCD Display and Pulse Repair - for Car, Lawn Mower, Motorcycle, Boat, SUV and More by Jeremy Tyson

The instruction manual is a bit sparse, so here's what I found out. There is a glowing button that looks like a fingerprint. Pressing this button toggles between wet, gel, motorcycle and repair functions. It automatically uses the battery you charge to power the display and show battery voltage and temperature. I used the previous charger with desulfurization (recovery) setting. My experience is that you have a really good battery if it recovers in about 4-8 hours. The full cycle takes 24 hours. You can run it 3 more times to max out the repairs and after that it's as repaired as it gets. Please note that this charger will not work if the battery is almost empty. If you plug in an old-fashioned "dumb" charger that pumps current into the battery, you can switch to that charger for repairs. I had a lawn mower battery that went dead pretty much every spring, but I was able to use it for 10 more years before I sold the mower. There's no reason to replace something like a lawnmower battery.