I have charged it with a very long extension cord which it said not to do - red and green light after 24 hours of both being on. I unplugged it, plugged it back in and got a green light. After that use I used a much shorter cord, left it for a couple days pulled the plug without checking the charge, checked the meter on the motor and it was 50%. I have a 24v 80lb trolling motor w/guest charger on my 2012 targa. The dealer is an hour away and don't want it sitting there for a week for them to change a fuse (which were all ok). 50% = 1 battery? Any ideas? Thank you!