Spec’ing for starting power
“With a large enough parasitic load, even the strongest batteries can be drained,” cautions Travis Down, applications and products engineer for Exide Technologies. That’s why it’s especially important to spec the right type of battery for your fleet’s needs.
Fleet managers also have the choice between two types of batteries: The classic flooded lead-acid, and the newer absorbed glassmat, valve regulated lead acid (AGM-VRLA). Generally speaking, AGM batteries hold a higher voltage and last longer. On the other hand, they are significantly more expensive than flooded lead-acid batteries. It all depends on the fleet. Fleet managers on the lookout for batteries should make sure they know their needs before making a choice.
One such need has to do with the route the truck drives. Trucks driving routes in very hot or very cold climates are more susceptible to battery failures than most, and there are many significant differences that drivers and fleet managers need to keep in mind when their routes go through these areas of extreme temperature.
“In hot weather, the batteries are easier to recharge, and it does not take as much to drive current back into the batteries,” says Purkey. “In cold weather, the batteries are like a tube of toothpaste: Hard to get anything out and damn near impossible to put anything back in!”
“High temperatures can deliver a perceived increase in battery capacity, however, long life is sacrificed,” notes Brad Bisaillon, Trojan Battery Co.’s director of strategic accounts and transportation sales. “On the other hand, extreme cold can reduce battery capacity, so charging (current and voltage) becomes even more critical as an undercharged battery can possibly freeze leading to a ‘no start.’”
The driver retention factor
“In this highly competitive driver market, driver recruitment and retention is key,” says Bisaillon. “Many fleet operators are using the inverters as a tool to attracting and keeping quality drivers. It is important to note, however, that these inverters need to be high quality with proper controls in place, and the fleet operators must spec the alternator capacity to align with the load profile.”
“It’s expensive to train drivers. It’s important to provide them with not only the tools to do their jobs well, but also to keep them comfortable,” says Essig of EnerSys. “Inadequately outfitting the truck can lead to driver frustration and poor driver retention. Large inverter power loads can drain batteries quickly and potentially cause no-start conditions.”
But Purkey cautions against making too many allowances for drivers: “We all know that drivers want it all and we all need drivers, but if the tractor does not start in the morning, neither the driver or fleet makes any money.”