Truck OEMs such as Peterbilt and Kenworth have recently made ultracapacitor engine start modules (ESM) available as a factory-installed option. The ultracapacitor replaces one traditional battery dedicated to starting the vehicle.
The ESM gives fleets assurance their engines will start reliably, especially for operations with multiple starts and stops per day or that use the lift gate or other auxiliary battery-powered equipment while the truck is off. Additionally, the ultracapacitor is not affected by hotel loads—lights, HVAC, television and other in-cab or sleeper-powered devices—which can drain power during extended use.
“Because an ultracapacitor-based starting system allows separation of the electrical loads of the truck into two systems—starting and parasitic—the batteries can be discharged independently of the power source used to crank and start the engine,” said Mark Burnside, Maxwell Technologies’ senior product manager of engine starting products. “As a result, the batteries can be discharged to a much lower level than before the installation of the ultracapacitor system without affecting the ability of the engine to start. Additionally, the truck’s batteries can now be replaced with true deep-cycle batteries, which provide substantially more run time for the parasitic loads than with standard SLI batteries.”