EP is Electric Powered GP i not sure maybe it meant the GP brand of rechargeble batteries .
My own 3s 5000mah lipos are really fully bloated and hard and i'm thinking of throwing it away after i get replacement before it turn my truck into a big fireball . And my lipo's are also getting longer and longer to balance charge . Simply love 3s 5000mah lipos as they leave a dust cloud behind my truck when it runs at full speed .
I also noticed that now my esc will cut off my lipo's at 7.6v for 2 s and 11.7 for 3s lipo's . I wonder why also .