I would say, its not normal for all three lights to go green in 5 minutes. At the risk of being Capt. Obvious, there is likely something wrong with the charger or batteries. When the lights go green, if you disconnect the charger and put a volt meter on your batteries, you should get a reading which would tell you whether they are charged or not. In my case, after fishing all day, the lights will turn green on my trolling motor batteries in about2-3 hours. My Pm1 will take 6-7 hours before the light turns green. This is using a Noco Genius charger.