Method and apparatus for determining the state-of-charge of batteries particularly lithium batteries
First Claim
1. The method of determining the state-of-charge of batteries, comprising the steps:
- (a) measuring the temperature of the battery;
(b) loading the battery with a predetermined load to produce a high discharge for a short predetermined time;
(c) after a short recovery time, measuring the recovered open-circuit-voltage and the corresponding recovery time of the battery; and
(d) determining the state-of-charge of the battery from the measured temperature and measured recovery open-circuit-voltage for the predetermined load and loading time and the recovery time of the particular type battery.
1 Assignment
0 Petitions
Accused Products
Abstract
Method and apparatus for determining the state-of-charge of batteries, particularly lithium batteries, involves the steps of: (a) measuring the temperature of the battery; (b) loading the battery to produce a high discharge for a short period of time; (c) after a short rest period, measuring the open-circuit-voltage of the battery; and (d) determining from the measured temperature and open-circuit-voltage the residual state-of-charge of the battery. Preferably, the residual state-of-charge of the battery is determined by comparing the measured temperature and open-circuit-voltage with reference tables showing the state-of-charge at different temperatures and open-circuit-voltages for the respective battery.
-
Citations
26 Claims
-
1. The method of determining the state-of-charge of batteries, comprising the steps:
-
(a) measuring the temperature of the battery; (b) loading the battery with a predetermined load to produce a high discharge for a short predetermined time; (c) after a short recovery time, measuring the recovered open-circuit-voltage and the corresponding recovery time of the battery; and (d) determining the state-of-charge of the battery from the measured temperature and measured recovery open-circuit-voltage for the predetermined load and loading time and the recovery time of the particular type battery. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. Apparatus for determining the state-of-charge of betteries, comprising:
-
(a) means for measuring the temperature of the battery; (b) means for loading the battery to produce a high predetermined discharge for a short predetermined time; (c) means effective, after a short recovery time, for measuring the recovered open-circuit-voltage and the corresponding recovery time of the battery; and (d) means for determining the state-of-charge of the battery from the measured temperature and the measured recovery open-circuit-voltage for the predetermined load and loading time and the recovery time of the particular type battery. - View Dependent Claims (12, 13, 14, 15, 16, 17)
-
-
18. Apparatus for determining the state-of-charge of a bettery, comprising:
- a temperature sensor for sensing the temperature of the battery;
a load resistor for connection across the terminals of the battery for loading same with a predetermined load;
measuring circuit means for measuring the temperature and also the battery voltage;
a timer circuit;
a display; and
a control system effective;(a) to connect said temperature sensor to said measuring circuit for measuring the temperature of the battery; (b) to thereafter connect said load resistor across the terminals of the battery for loading same for a short time interval as predetermined by said timer circuit; (c) after a short recovery time as determined by said timer circuit, to connect the battery to said measuring means to measure the battery recovery open-circuit-voltage; and (d) to display a value corresponding to said measured recovery voltage on said display. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26)
- a temperature sensor for sensing the temperature of the battery;
Specification