George we use a second battery to start our car. We use a small battery on board for the transbake and recorder. It is enough of a battery to start the dragster if I stall it after the burnout, but it struggles to do it.
We use a heavy duty cable connector like you would have for a blower starter or winch. It is mounted at the rear of the car just under the seat near the lower wheelie bar mount. We use a battery cart with either 1 or 2 batteries to start the car and then just disconnect and pull forward. The small battery stays on the charger while in the pits. We run a mag usually but will be using our MSD ignition on the engine in the car now.
We do have a new 16V battery that was given to us by one of our sponsors, BUT WOW are the chargers expensive.
I need to stop being cheap and just get one.