Abstract: A method and apparatus for charging nickel-cadmium batteries with a current greater than 2C rate. The cell temperature or both the temperature and voltage thereof are monitored, and the charging operation is halted upon detection of a moment when the rate of temperature increase of the cell became at least twice as great as the rate of temperature increase that was measured just before, or of a moment at which the above phenomenon took place and a moment at which the rate of voltage increase has declined immediately following a period during which the rate of voltage increase has continually risen.

Abstract: A device for and a method of indicating the residual capacity of a secondary cell, that needs be recharged using a simply constituted device, correctly and within a short period of time.