i made my own battery pack here:
http://www.cheapbatterypacks.com/i used elite 2000mah 9.6v(8cell) crane stock configuration
its tricky to place it in the crane stock but can be done
or if you dont want the hassle
http://eliteairsoftbatteries.com/produc ... -pack.aspxbut it is only a 7.2v
the 9.6v will most likely be too long for the cranestock but use the measurements they give you and compare it to your stock
http://eliteairsoftbatteries.com/produc ... -pack.aspxnot sure what wire gauge their using on their premade ones but you can always make one yourself and use the gauge you want.
PS: oh theyve also premade what i made before:
http://eliteairsoftbatteries.com/produc ... -pack.aspxPSS: 2000mah and the 2100mah are practically the same thing