Ok, well did you use a 6 amp charge? Also, did it count down from 6 to 5.9...5.8..5.7...4.5..4..3...2.5..2...1.. like that ?

It should automatically select the right setting so you don't have to worry about it but I usually manually select mine. You probably didn't have much more to go if you stopped it at 3.70v . Next one you charge, measure the whole 4 cell pack and see if it stop at 14.88v . that's what mine does.