Must-do truck battery maintenance in the shop
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Must-do truck battery maintenance in the shop

Jason Morgan is the content director of Fleet Equipment.


You want to catch as many potential truck battery problems before they happen as you can, and that means checking the truck electrical system during preventative maintenance. Here’s how to get started.

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First, safety.

“Technicians should always follow the shop rules for PPE equipment,” said Larry Rambeaux, sales application engineer for Purkeys.

“The most obvious is safety glasses; a shield is even better,” said Steven Keuss, engineering manager for Associated Equipment Corp. “Another safety practice I like to follow is to avoid tools that can accidentally short between battery posts; for instance, long metal wrenches used under the hood. A battery can turn something as innocuous as a wrench into a welding rod really quickly.”

“Technicians should be trained on proper battery training and testing,” Rambeaux agreed. “A battery that is low on electrolyte or has been overcharged can be very dangerous, as the battery can give off pure hydrogen and pure oxygen that is in a perfect mixture to be very explosive, and the liquid is highly corrosive.”


“A smock is also a good idea to save clothing and uniforms from being damaged by battery acid or other residues,” Keuss said.

“Rubber gloves should also be worn,” said Vicki Hall, director of transportation technical solutions for EnerSys, “as some batteries contain liquid electrolyte [sulfuric acid]. Technicians should always use insulated tools to avoid short-circuiting the battery. And they should never smoke near the batteries or place metal objects on the tops of the batteries.”

Once outfitted for the job, charging plays a large role in preventative maintenance. When a truck is in a bay, that’s a charging opportunity.

“Opportunity charging is recommended during any PM or service,” said Jeff Muir, director of original equipment sales, commercial and outdoor power equipment for East Penn. “Place a charger that is equal to or more than the amperage being drained while being serviced or repaired. This act will help to recharge the battery pack and offset loads while the truck is being worked on.”

Be sure to use a charger that’s designed for that battery type. “Most shop chargers are designed for flooded lead batteries,” Muir said. “However if using AGM batteries, the charger must be AGM compatible. Using the wrong charge profile will overcharge an AGM battery.”


Muir went on to also advise the following:

  • If a no-start or jump start occurs, remove the batteries and charge with an external charger. To prevent a repeat occurrence, ask why the batteries may have been discharged.
  • If an excessive discharge event occurs, recharge promptly with an external charger to minimize degradation. Recharge effectively to restore performance, i.e. sufficient amp hours.
  • To maintain battery connections:
    1. Clean connections by removing any type of dirt, grime or corrosion;
    2. Coat unsealed battery connections with dielectric grease only after the connections are made. (Note: you never want grease in between the connections, as this would allow the connection to become loose and then create resistance);
    3. Check and confirm torque values of the group 31 nuts based on BCI standards; and confirm security of the hold downs.

Read our in-depth story on how summer heat drains your truck batteries (and what you can do about it) here.

Fleet Equipment Magazine