(EDITOR's NOTE: Ground Support Worldwide welcomes back Todd Allen, Allen Energy, who returns to write a monthly blog on electric ground support equipment.)
TRUE OR FALSE: You must fully discharge a battery or it will develop a “memory.”
FALSE: Industrial lead-acid batteries found in electric ground support equipment do not develop a memory. Many people believe that if you only partially discharge a battery, it will “remember” a typical discharge level. And then it will not go past that level when you need more power.
I believe this myth originated during a period of time when Nickel-Cadmium and Nickel Metal Hydride batteries were popular in consumer electronics. People would charge their devices after a short period of use and they quickly discovered that the battery developed a memory effect and had significantly reduced capacity.
This myth continues on today even though it is not true for lead-acid or other battery technologies such as lithium. Particularly in fast-charge and opportunity-charge applications, it is perfectly acceptable to partially discharge and plug back in. There will be no loss of capacity.
However, there are a two cautionary notes I'd like to add: Do not over-discharge or under-charge.
- Do not over-discharge: You shouldn’t over discharge your lead-acid battery. It is very important for battery performance and life to limit the discharge to 80 percent of the battery’s capacity. The vehicle controller should manage this automatically, but they are often out of calibration. Or more often, operators find a way to over-ride the controller.
- Do not under-charge: Also, you should charge your battery to 100 percent state-of-charge regularly – daily if possible. Failure to do this will also reduce battery performance and life.
Return back next month with Battery Myth No. 2
