Originally Posted by
Skynet
Sorry I didn't mention, but the battery need to be a hardcase as Roar and Efra only accept these type of packs.
One note that if you are going by ROAR rules then it has to be an approved hard case pack. So a hard case pack from HobbyKing will probably not work for you as I don't believe they have been approved by ROAR. You are pretty much stuck with the more expensive name brand car oriented packs.