We use a remote, hand held, battery pack, that weighs 10 lbs with cables and alum box. Most JrFuel cars use 24 volt battery because of the high compression and magneto.
The light weight battery pack because it's a lot faster/ easier than jocking the tow truck around to get it in the right spot to start. Because it is hand held, the cables are just 3 feet long. The battery is just charged at home, and don't need to charge at the races unless we have to spin the motor over a bunch because of some problem.
Jon Hansen