Need some advice please. running 1100v motors kk2.1.5 board at this time using 2200 turniguy 2200 mah 20 30c discharge. i have found that two of the batteries have puffup and getting very hot to touch. i was wondering if i could use a 4000 mah. and would i need a new charger. i have a duratrax li 24. thanks