02 April 2008
Lead batteries come in two basic types: starter batteries, which are made for maximum CCA (cold cranking amp), and deep cycle batteries designed for a maximum capacity and high cycle count.
Deep cycle batteries are the type found on scissor lifts and other battery run pieces of access equipment. Battery run time is dependent on capacity: capacity defines the energy a battery can hold and is specified in ampere hours.
There are several ‘health' measures for batteries: SoC (state of charge), capacity and mismatching.
• LOW CHARGE Low charge reduces the drive power and the battery appears weak. If you check the battery with a discharge unit a false low capacity will show. A rapid tester such as the Spectro CA-12 unit can measure capacity with an SoC of as little as 40%. If the charge is lower the instrument will give a prompt to charge and retest.
• LOW CAPACITY A low capacity battery with a build up of ‘rock‘ is likely to have good conductivity and a strong torque. The voltage appears fine and everything seams normal except for the short runtime. Knowing the capacity of an aging deep cycle battery is very important because it is the best indication of when a battery should be replaced.