City Transit Bus Battery System
Over their lifetime, batteries for the engine starting of a city transit bus must consistently deliver high cold cranking amps, which can be especially challenging during extremely cold weather. With the engine off, a high cycle reserve capacity is required to support loads such as interior lighting, blower fans, dash and monitoring systems, chair lifts and fare boxes. The alternator is the sole charging source for transit bus batteries, and undercharging is expected due to overloading the alternator. City transit bus batteries will often need to accept a high charge current after spending extended overnight periods in a discharged state. Alternator voltage is often poorly regulated, which may cause long-term damage to the batteries.
Battery failure is most commonly caused by acid stratification, extreme temperatures and destructive over-the-road vibration. Acid stratification naturally occurs in flooded lead-acid batteries and leads to a decline in capacity and charge acceptance. AGM technology and acid mixing technology for flooded lead-acid will mitigate acid stratification. A maintenance-free spill-proof battery is highly desirable.