I thought I'd buy a better charger for the new best Nortstar AGM battery. Not as much. Despite all the talk about this charger not being designed to charge batteries, it did just that. (Northstar AGM27F, 92AH battery for my Tacoma). It's a bit wacky, but I've never had another charger do this, and I've had a few - first time use, left it in the garage for an hour or two, went out for another reason and when I got this next time the battery went i heard a gurgle, a bad sign of an AGM battery. You can google. I left it running for a while in case it was something temporary, but it persisted so of course I turned it off. Who knows what damage it has done in that time, but I wouldn't trust leaving it on even overnight. I have a few other chargers, just needed another one and thought I was getting "the best". Well it isn't. I'm about to order another Noco in the same size after I'm done with this one. The 7200 did the job perfectly, I don't know why I decided to try something else.