System and methods for evaluating a charge state of a battery are provided.
A light source is configured for emitting light through an electrolyte contained
within the battery. An optical element determines the charge state based on the
light passing through the electrolyte. The optical element may comprise an optical
sensor such as a CCD. Such a CCD may be used to determine the location of light
impinging the surface of the CCD. In one embodiment, the system includes a processor
for determining the index of refraction for the electrolyte based on the location
where refracted light impinges a CCD. From that index of refraction, a specific
gravity of the electrolyte may be calculated to determine the charge state of the battery.
