BATTERY CONDITIONING

1/10/2003

Battery Conditioning is a form of black magic that purports to improve the storage capacity of batteries by manipulating the charge and discharge of batteries through one or more charge/discharge cycles. The theory behind conditioning appears to be sound. It is not certain that conditioners always achieve what they claim. Conditioning addresses two issues.

Dendrites are crystalline growths that may form in the electrolyte of batteries. The dendrites act as electrically conductive, but non-energy storing, extensions to the electrodes. They also tend to plug the pores of separators that are intended to keep electrodes apart while permitting current flow. In the worst case, dendrites may short out the cell. Once formed, the only established method of removing them is by discharging a large capacity capacitor through the cell. That procedure probably will not work for all chemistries; is not suited to multi cell batteries; and may damage even single cells. It is asserted that a series of properly controlled charge and discharge cycles can reduce the size of dendrites.

Batteries with Lithium compound anodes are subject to another condition. "Lithium" batteries have a longer shelf life than many other modern portable equipment batteries. This is due to the spontaneous formation of a "passivation layer" of Lithium Chloride that prevents self discharge. Unfortunately, the passivation layer has to be removed by forward current flow before the cells can deliver their full voltage and current. This results in an initial period of low voltage when a device using a Lithium battery is turned on. It may also limit the storage capacity of the battery. In the worst case, safety circuitry required in some Lithium batteries may shut the cell off because the initial voltages delivered are too low. It is asserted that properly controlled charge and discharge cycling can control the extent and other properties of the passivation layer.

Commercial battery conditioners are available. Different conditioning cycles are surely needed for different battery chemistries, and quite possibly for different internal physical features as well. There is no real proof that battery conditioners work any better than baldness cures. Failure to use the proper conditioner for a specific battery type (and possibly specific internal construction) could, in principal, lead to damage to the battery, the conditioner, and potentially -- should the battery explode -- to the operator, facility, household pets, etc. Destruction of civilization, the planet or galaxy through use of the wrong conditioning cycle is unlikely.