Written By: Randy Anderson, Technical Sales & Training Manager
Over the past 20 years we have witnessed significant changes in the transportation industry from fuel efficiency, power requirements, safety features, onboard electronics and the list goes on. While in many cases the traditional electrical power requirements for these vehicles has diminished due to solid state circuitry and LED lighting the addition of creature comforts and on board electronics has in many vehicles surpassed that of the energy saving components.
There is no better example of this than Urban Transit Vehicles. Todays buses are generally diesel powered or hybrid diesel electric and in many jurisdictions it is required that the engine be shut off when the bus is making stops longer then 3-5 minutes. During these engine off-stops, the 12 volt electrical loads consisting of fare boxes, lighting, destination boards and heating or cooling loads must be picked up by the vehicle batteries. This shift of power has created a challenge for most bus starting batteries as traditional lead acid engine starting batteries are not designed to be cycled or discharged and recharged multiple times, these batteries are simply designed to provide power to start the engine and then be quickly recharged by the vehicle charging system.
Change is now required in the types of batteries that are used in these applications. Hybrid or Deep Cycle batteries must now be substituted in place of the starting batteries that were once common to all buses, these batteries are built to withstand the multiple cycles they may encounter during a normal shift. Another remedy that is not widely accepted yet in the industry is to leave the traditional starting batteries to perform engine starting duties and move all off key electrical loads to a set of auxiliary or house batteries. These batteries would be deep cycle and designed for the sole purpose of multiple discharges and recharges, this would ensure that the starting batteries were always in a full state of charge and “no starts” would be avoided.
In many cases transit operators have chose to stick with the traditional starting batteries because they are less expensive to purchase than hybrid or deep cycle batteries under the belief that they are saving money in up front costs. This short-term thinking then places the burden on the maintenance departments as they deal with increased labour costs associated with changing out batteries, dealing with buses that won’t start on the road and schedule irregularities due to buses being down for unscheduled repairs.
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