Disconnecting
Electrical demand is often still placed on the truck’s batteries even when the truck is turned off. One way to control the amount of power being drained is to use low voltage disconnects (LVDs). The main reason for using an LVD is to protect the starting power and life of a primary battery. As the battery runs down, the LVD shuts off power to non-essential (non-safety related) loads to assure that the battery has enough power to restart the vehicle. If the voltage goes above the reconnect voltage, the LVD reconnects the loads automatically.
“The most common components connected to LVDs we see are the manual battery shut downs,” Mitsubishi Electric’s Ritter said. “These completely disconnect the batteries from the truck, thus prolonging battery life. With some electric auxiliary power units [APUs], there is an automated system that shuts down when low battery voltage is reached to protect the cranking cycle. There can also be a split battery system where hotel loads are running from a number of batteries that are separated from the cranking batteries.”
According to Purkeys’ Atkinson, it is important to use LVDs in nearly all cases on non-safety related components. It’s also imperative to understand the true maximum amperage demand of your application in winter and summer and make certain that the chosen alternator is sufficient for the electrical demand.
“Many overlook that [the energy for] today’s add-on equipment comes from the battery pack,” he said. “It must always be protected, managed and never allowed to rest in a discharged state for a prolonged period of time.”
“To get the most miles from your truck’s batteries and electrical system, make a habit of powering down any non-vital accessories when the truck is not running,” Adam Bean, Phillips Industries’ research and development engineer, added.
Empowering maintenance
As with many similar issues, quality maintenance procedures can save you a many headaches down the road. Application is going to determine much of your maintenance operations.
“Each fleet has a different business model, take the length of trips between stops as an example,” said Brad Bisaillon, director of strategic accounts and transportation sales for Trojan Battery Co. “Fleets with longer distances between stops and shut downs will have a better opportunity for their batteries to be fully charged. We recommend going from a three-battery set up to a four-battery set up for additional loads. Also, we recommend ensuring a more robust alternator and cable size to accommodate the additional charge.”
When your trucks do pull into the yard, it’s important to service your truck’s batteries properly.
“Inspect terminals and lugs for gassing residue and corrosion, and connections should be clean and tight,” Phillips Industries’ Bean recommended. “Serviceable batteries need to have the fluid levels checked regularly and only at full charge. Perform a load test every three months to determine if there are any batteries in need of replacement.
“To prevent corrosion of cables on top post batteries,” he continued, “use a small bead of silicon sealer at the base of the post and place a felt battery washer over it. Coat the washer with high temperature grease or petroleum jelly. Then place cable on post and tighten, coat the exposed cable end with the grease. The gases from the battery condensing on metal parts cause most corrosion.”
“Maintenance and more maintenance,” recommended Mitsubishi Electric’s Ritter. “It’s cheaper to do this while the trucks are in your shop. If not, towing bills and battery jump starts are headed your way. Install a battery shut down system on new trucks, and teach your drivers to use them.”
