In their catalog, they have a pack designed for some sub-c batteries that attaches to the starter. The Sullivan website.

"PowerPac Battery Case. Holds 12 Sub-C NiCad batteries, providing 14.4V of high amperage power. The PowerPac will deliver as much torque as a motorcycle battery.

Fits all Sullivan Starters as well as most other brands (may require minor bracket modification). For 24V applications, two PowerPacs and be connected in series. For installation instructions on the Dynatron starter, click here.

The case features glass filled resin construction, cooling slots and bronze contacts (no soldering is required). Includes UL listed trickle charger. NiCad batteries and starter not included. Uses twelve 1200 mAH or higher Sub-C NiCad batteries. For installation instructions follow this link. No. S640."

http://www.sullivanproducts.com/Star...sMainFrame.htm