Cell type determination of battery under charge conditions
AssigneeHewlett-Packard Company
InventorsCharles S. Stephens, Dennis Schloeman
Life of this patent
Estimating the term…
Abstract
The cell type (i.e. alkaline, Ni-Cd, etc.) of a battery is determined by reference to characteristics of its electrical behavior during charging. Exemplary characteristics include the magnitude of the initial voltage rise and the rate of initial voltage rise. Depending on the outcome of this determination, the charging conditions can be changed (e.g. the charging current can be interrupted if the cell is determined to be a non-rechargeable type). The invention finds particular utility in connection with electronic products such as calculators and portable computers.
Claims21
A method for determining the cell technology of a battery when charging, comprising:
- applying a DC charging current to the battery;
- monitoring the terminal voltage of the battery to determine an initial charging characteristic of the battery terminal voltage relating to the applied DC charging current;
- correlating the characteristic with known characteristics of at least first and second cell technologies;
- and
- producing an output signal responsive to said correlation to indicate the cell technology of the battery.
An apparatus for determining the cell technology of a battery being charged, comprising:
- a current source connectable to a battery for applying a DC charging current thereto;
- monitoring circuitry adapted for coupling to the battery and for monitoring an initial electrical parameter thereof relating to the applied DC charging current;
- comparator circuitry coupled to the monitoring circuitry for comparing the monitored parameter with a reference parameter;
- and
- indicating circuitry coupled to the comparator circuitry for producing an indication of whether the monitored parameter corresponds to first or second cell technologies.
A method for determining the cell technology of a battery when charging, comprising:
- applying a substantially constant charging current to the battery;
- monitoring the terminal voltage of the battery to determine an initial charging characteristic of the total battery terminal voltage relating to the substantially constant charging current;
- correlating the characteristic with known characteristics of at least first and second cell technologies;
- and
- producing an output signal responsive to said correlation to indicate the cell technology of the battery.
A method for determining the cell technology of a battery when charging, comprising:
- applying a substantially constant charging current to the battery;
- monitoring the terminal voltage of the battery to determine a characteristic of the initial rise of battery terminal voltage after the charging current is applied;
- correlating the characteristic with known characteristics of at least first and second cell technologies;
- and
- producing an output signal responsive to said correlation to indicate the cell technology of the battery.
Dependencies are inferred from the claim text.