VTEC
im not sure about wireing them together.
you can buy a pack for like 20.00 bux.
7.4 volt 2 cell 250 mah.
http://www.hobby-lobby.com/etec.htm
you can just chek it every once in a while on your charger.
just get used to the runtime and youll be able to keep it above its cutoff.
i dont like to let my packs go below 11 volts because then you have to start balance charging them to keep em tip top.
o and fritz.
i have the 7.4 250 etec. and even if i remove the covering i still dont see how i can fit it in there