+1 on going 6v for all Spektrum equipment. Also, all receiver plugs currently manufactured are the same, so there's no need to worry about polarity on the packs. If it's in your budget to include a computerized charger, I'll suggest getting one and going with a Lipo battery attached to your starter. It's so much more convenient to handle it as a unit than to lug a 12v lead battery out and have the cord to deal with.