Battery charger with transducer for controlling charge rate

Abstract

Disclosed herein is an apparatus for charging a battery including a case containing at least one cell formed of a pair of electrodes immersed in an electrolyte. The apparatus includes a transducer associated with the battery and operable without sensing gas pressure in the battery case for providing a variable signal output in response to electrolyte gassing within the battery case. The apparatus also includes a control circuit arrangement coupled to the signal output for providing a variable control output in response to the signal output, and a battery charger connected to the battery electrodes and operable for charging the battery at a rate subject to the variable control output. In one embodiment of the invention, the transducer is a sound transducer, preferably a ceramic microphone, which provides a variable signal output in response to sound generated within the battery case. In another embodiment, the transducer is a fluid vibration transducer, preferably utilizing a piezo-electric element, which provides a variable signal output in response to fluid vibration in the battery electrolyte. In another embodiment, the battery charger includes a battery temperature detector, preferably utilizing a thermistor, which prevents the battery charger from charging the battery when the temperature of the battery electrolyte exceeds a predetermined upper limit or electrolyte level is low.

Dependencies are inferred from the claim text.