I've got the name brand "Battery Tender" and have been using it for years. In the past, I've always used the alligator clips to charge my batteries but with my new sled (Polaris VR1) it has the built in bullet connector, so I'm plugged into that now. I've had batteries take a few days to get the green light indicator to come on, but I'm going on Day #5 with this one and it's still solid red. Turning the key on, and looking at the voltage reading, I was at 11.4 yesterday (haven't looked yet today) .... but I would have expected it to be CLOSE by now and in that low 13.x range. Maybe I should just disconnect the bullet connector and go back to the clips and see if that makes a difference, but curious what kind of feedback others have seen regarding how long it takes to get to a full charge?