Abstract: A battery charging system (200) includes a field-effect transistor (212) as a current discharge protection device in order to prevent current from flowing from battery (222) to charger (202) when charger (202) is not charging or discharging battery (222). The field-effect transistor (212) also protects battery (222) in the case that the battery contacts are inadvertently shorted. When charger (202) is charging battery (222), field-effect transistor (212) is turned on, providing for reduced voltage drop across the device due to its low on resistance, and also allows for charger (202) to charge and discharge (condition) battery (222).

Abstract: A battery having a self testing feature for its intrinsic safety circuitry is provided. The battery uses light emitting diodes to indicate the operation of safety circuit in the battery. The safety circuitry of the battery may be tested by providing a short across the battery terminals, if the associated circuitry is operational the light emitting diode will light. This feature will also indicate, when the load across the battery is shorted.