Summer heat can weaken truck batteries long before winter temperatures expose the damage, while new battery monitoring technologies are helping fleets identify electrical problems before they cause no-starts. But vocational trucks face additional challenges, with demanding duty cycles, frequent stops, and auxiliary equipment placing even greater strain on batteries and charging systems.

High demands

Work trucks will typically have much higher electrical demand than on-highway tractors, noted International’s Anthony Tondola. “Trucks used in vocational applications like snowplows, refuse hauling, utilities, and others operate hydraulic systems, lift gates, warning lights, camera systems, spreaders, and power-take-off (PTO) driven equipment while spending extended time at idle,” he said. “These extra electrical loads, along with severe duty cycles, can create situations where electrical demand can exceed charging system output and lead to battery undercharging.

“For a vocational vehicle application, fleets should ensure that battery quantity and sizing, alternator sizing, and idle management strategies are appropriate,” Tondola added. “Regular inspection of battery connections, grounds, and charging system performance is especially important for equipment operating in severe environments.”

A key differential for vocational vehicles can be exposure to short trip usage patterns, which is very taxing on batteries, noted Jim O’Hara at Clore Automotive. “In these scenarios, this usage pattern can result in significant battery pack depletion, so we suggest overnight or off-shift charging to bring the packs back to full charge when not in use.”

There are other unique considerations for batteries on work trucks and vocational vehicles, according to Jim Bevan at Enersys. “These vehicles are typically subject to an above-average amount of corrosion due to substantial exposure to salt, harsh chemicals, and other dirt and debris. Their more extreme use cases also typically result in more starts than other vehicles, frequent stopping, and more vibration. These characteristics put more loads on the batteries and starting and charging systems.

“Duty cycle and alternator sizing are critical considerations for preventing battery undercharge in vocational vehicles,” Bevan added. “There is also a misconception that vocational trucks only need a starting battery because they don’t have traditional hotel loads. However, vocational trucks typically have moderate cycling application needs due to engine-off accessories that can be used by a driver. As such, dual-purpose cycling batteries are optimal.”

Liftgates can place significant electrical demand on a truck, particularly when they are operated repeatedly without enough time to replenish the battery bank, noted Wade Seaburg at Dragonfly.

“In traditional configurations where the liftgate and chassis starting batteries are tied together, repeated liftgate use can draw down the starting bank far enough to create starting issues,” Seaburg said. “Separating the liftgate load with a dedicated auxiliary battery bank helps preserve the energy needed to start the vehicle while allowing the equipment to operate independently.”