Gregg I run one single 4s 5000mah lipo velcro'd down with a strap over it for safety.. its really unneeded. Just incase I come off " THE BIG ONE" and land funny. I learned from the last 3 electric buggies... velcro your batteries down and they wont move AT ALL In fact its kinda a P.I.T.A to get them out after a good run.