WHILE INVERTERS have improved life on the road for drivers, they pose a potential predicament for fleet operators. Most fleet owners realize they can attract and retain drivers by allowing inverters on their trucks. They also realize that unauthorized or improper use of inverters can lead to expensive electrical problems.
Inverters, which convert stored energy from a truck's batteries into AC electrical power, enable drivers to use electrical conveniences such as laptop computers, entertainment systems, and cooking appliances in their cabs.
Such benefits have caused inverter sales to surge. Inverter sales are growing 20%-30% per year, and sales exceeded 200,000 units in 2002, according to J Stanley Saunders, marketing director-aftermarket for Delco Remy America Inc.
But problems can arise when a driver operates an inverter that lacks protective safeguards or installs it improperly. “A lot of drivers don't know to look for inverters that have battery protection,” said Saunders. “This simple feature shuts the inverter off before battery levels get too low. Without this feature, the inverter sucks the life out of the battery.”
According to Saunders, each time battery voltage drops below a recommended level, battery life is shortened considerably. “If your battery is taxed by heavy drawdowns, then your starter works harder, and so does your alternator,” he says. “All three devices end up wearing out faster.”
To combat these problems, fleets adopt various policies. Many impose a “no-inverter” policy for their trucks, believing that by prohibiting the product they can prevent the problem. Some drivers buy the inverters anyway. Drivers frequently attempt to hide inverter use by removing the devices before turning in a truck, according to Bob Jeffries, regional sales and service manager for Delco Remy.
“By following a no-inverter policy, fleets are helping to create an underground where drivers make temporary installations,” Jeffries said. “Unfortunately, electrical problems are resulting from these jerry-rigged installations. The average fleet jump-starts 10% of its trucks each month. Furthermore, an average of 15% of those jump-starts are due to excessive electrical loads in the cab.”
Fleets should select — or allow their drivers to buy — an inverter that offers a low-voltage battery cutoff, which shuts down the AC power before the battery is depleted.
Look for other safety features such as ground fault circuit interruption. Another important feature is rating the wattage at “continuous” power rather than “peak” power designed to handle a power surge.
The most popular inverter with drivers is a 300-watt unit that costs about $40 at truckstops. Drivers often plug the device into the cigarette lighter to power appliances. “The problem is a cigarette lighter is designed for plug-ins of up to 150 watts,” Jeffries said. “When the load exceeds that, electrical problems can arise.”