A method for determining the state of a battery, or battery pack, that is
independent of the type of battery technology under test. The method
employs one or more charging and discharging cycles, and measures one or
more parameters of battery voltage, temperature, charging time, and
charging cycle counts to produce a test value that is compared to
empirical data. Based on the comparison, the state is determined, for
example, on a pass/fail basis. The method may be embodied as instructions
stored in memory and implemented by means of a microprocessor coupled to
the memory. In another embodiment, the empirical data is stored within
another memory located internal to the battery pack under test.