How To: Maintain batteries
Despite improvements in manufacturing and materials, it’s important to stay on top of your batteries’ condition to prevent premature failure.
Thanks to improvements in manufacturing and materials, the number of threats to battery longevity has been reduced from three to one. Unfortunately, the remaining problem isn’t going away anytime soon.
battery longevity has been reduced from three to one. Unfortunately, the remaining problem isn’t going away anytime soon.
Not long ago, the life of many truck batteries was cut short by vibration, overheating or deep discharging, a.k.a. deep cycling. Only the last causes much trouble nowadays, but that’s little comfort to truckers who accidentally have left on-board appliances running while their trucks are shut down for a few days, prompting an unscheduled trip to a battery dealer.
Even when current drain is stopped before replacements are needed, deep cycling can cause permanent damage, says Gale Kimbrough, technical services manager for Interstate Batteries in Dallas.
“Every time you take a starting battery below 50 percent depth of discharge, you’ve eliminated hundreds of normal starting cycles,” Kimbrough says. “Deep cycling deteriorates the batteries’ paste material, which is the chemical substance that actually creates electricity.”
Kimbrough advocates low-voltage-disconnect devices to prevent such problems. These cut the power supply to cab fixtures and outlets when battery voltage falls below a set limit, usually 12.2 to 12.3 volts. A lot of company trucks are fitted with LVDs, much to the disappointment of drivers whose electrical creature comforts occasionally are shut off. Normal current is restored as soon as an afflicted truck’s engine is started.
Battery failures seem to occur most frequently in winter, when starting-power demands increase and battery-power output decreases, the result of slower chemical reactions. Oddly, though, low temperature usually does not harm batteries. It just makes their job more difficult. High temperature is the real killer, says John Miller, senior director of product engineering for Exide Technologies in Alpharetta, Ga.
“I’d bet that most of the batteries dying in winter were severely wounded during the previous summer,” he says. “Heat is really tough on battery components.”
Manufacturers have been able to reduce this problem by using different chemistry. “Within the past five or so years, most heavy-duty battery makers moved to calcium-based or calcium-tin-based alloys,” Miller says. “That’s offered extra protection against overcharging, heat and gassing, which leads to electrolyte loss.”
Buyers can further avoid heat-related trouble by selecting the correct batteries for their operating environment. Doug Merrill, product specialist for ACDelco in Grand Blanc, Mich., warns against buying batteries with excessive cold-cranking amps. “High CCA capacity is important to truckers in extremely cold climates, but it can be detrimental for others,” he says. “Cold cranking output is achieved with additional internal plates. But more plates means more heat.” Ask a reputable dealer for advice on battery selection, Merrill suggests.
The number of batteries on a truck is an equally important consideration, says Interstate’s Kimbrough. “With the types of accessory loads trucks carry today, four-battery sets are better than those with three,” he says. “For example, three 950-CCA batteries will deliver 2,850 cold cranking amps and have about nine hours of reserve capacity [at 3 hours each]. However, four 700-CCA batteries will offer 2,800 cold cranking amps, plus three extra hours of reserve capacity.”