Nickel-cadmium battery state-of-charge measuring method

Patent · Tue Feb 17 04:00:00 EST 1987

OSTI ID:6743930

Brown, H B

A method is described for determining the state of charge of a nickel-cadmium battery, which comprises discharging the battery through a low impedance path at the rate of about 50 to 80 amperes for a pulse discharge period of about one millisecond, measuring the highest battery terminal voltage sustained during the major portion of the discharge period, wherein the battery terminal voltage is stored in a capacitor which is connected across a battery current path concurrently with the pulse discharge period, and wherein the charge remaining in the capacitor is measured subsequent to the termination of the discharge period, wherein the low impedance path includes a resistor of relatively low impedance and wherein the high impedance path includes a resistor of relatively high impedance, wherein the resistors are in parallel to the battery throughout the pulse discharge period and for time intervals preceding the pulse discharge period, further including the step of shorting to the high impedance resistor throughout the pulse discharge period.

• Assignee: Applied Electro Mechanics, Inc., Alexandria, VA
• Patent Number(s): US 4644245
• OSTI ID: 6743930
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
250902* -- Energy Storage-- Batteries-- Performance & Testing
CAPACITORS
CHARGE STATE
CONDUCTOR DEVICES
CONNECTORS
ELECTRIC BATTERIES
ELECTRIC CONTACTS
ELECTRIC DISCHARGES
ELECTRIC IMPEDANCE
ELECTRIC POTENTIAL
ELECTRICAL EQUIPMENT
ELECTROCHEMICAL CELLS
EQUIPMENT
IMPEDANCE
MEASURING METHODS
METAL-METAL OXIDE BATTERIES
NICKEL-CADMIUM BATTERIES
PERFORMANCE TESTING
PULSES
RESISTORS
TESTING
TIME DEPENDENCE