I purchased several used 12v gel cell batteries that needed deep charging. A few of the chargers I owned did not work. It was either properly dispose the batteries or try this charger. I used the same brand for a 6v light bike light system before LED's in the 1990's. This charger recovered all but one battery that was bad. It can take 2-3 days for a near dead battery to charge. A red to green indicator allows you to monitor the charge.
Good product and excellent service!
Can put a PS 1270F1 battery on the charger and forget it until I need the battery. If I had electricity to the feeder, I could hookup the installed battery and keep it hot instead of changing batteries when the installed battery goes down. Have used solar chargers but have had limited success with them.