Back to Basics: Batteries

There’s a certain amount of alchemy at play when dealing with automotive batteries. Even fleet managers with years of experience aren’t always sure if they’re dealing with a battery that needs to be junked or one that can be resurrected to keep delivering dependable service.

At the Technology & Maintenance Council’s Fall Meeting in Cleveland on Sept. 14, a panel of battery experts attempted to demystify batteries and provide some helpful pointers for keeping them in service as long as possible.

Jeff Muir, director, original equipment sales, East Penn. Manufacturing, noted that demands on batteries are only increasing today, as drivers add more electronic devices, such as Crock Pots, TVs, and game consoles. “And that’s on the ‘hoteling’ side of things,” Muir said. “There are also more operational demands on batteries today, such as telematics and over-the-air updates. So, keeping batteries in top condition is more important then ever.”

John Cathey, field sales support manager, original equipment, East Penn. Manufacturing, said that he tells technicians to think of batteries like the fuel tank on a truck: Just because the tank is empty, it doesn’t mean there’s something wrong with the tank.

“If you test a battery and get a reading above 10.9 volts, it’s a good sign you don’t have a dead cell on your hands and you can recharge it,” he explained. “But most technicians don’t understand what has happened when there’s a battery discharge. And if it’s taking a long time to recharge a battery, they just assume it’s dead and replace it.”

Temperature impact

It’s also important to remember that batteries do not like extreme temperatures, Muir noted. Even an increase of 20 degrees F can cause battery life to decrease significantly. But, he added, the best course of action for fleets is to always recharge batteries to a full state charge after a discharge. “If a key or lights are left on, it’s not the batteries fault,” he said. “And it takes time for a battery to recharge after a discharge like that. Don’t let batteries sit long in a low state of charge because its ability to take and maintain a charge will degrade significantly over time.”  

Another important point the panelists drove home was the fact that many fleets do not regularly check and calibrate their battery diagnostic tools to make sure they’re getting accurate readings. They recommended doing so at least once a year. One easy way to do so, Muir said, was to take multiple readings when a pallet of new batteries arrives and check to see if the readings are consistent.

Luckily for fleet managers, the panel noted, TMC has a wide range of Recommended Practices (RPs) to help diagnose, install, and care for heavy- duty batteries in commercial vehicles. Those include:

• RP 129 — Cranking and Charging Requirements
• RP 132b — Battery Charging and Testing
• RP 136b — Managed Isolated Systems for Electric Start
• RP 140 — Understanding Key-Off Parasitic Loads
• RP 158 — Wiring and Circuit Protection Guidelines for 12 Volt Cab and Sleeper Power Outlets
• RP 166 — HD Electrical Repair
• RP 178 —  Battery Management and Cable Guidelines for Meeting Hotel Load Requirements
• RP 179 — Liftgate Charging and Pump Motor Diagnostics and Maintenance

“There are two clocks ticking when you buy a battery,” Muir said. “Cycles and the calendar. You can eventually use a battery up, or it will die of old age. But how long it lasts depends on how well you maintain it during its service life.”