US 6,388,426 B1 · Battery power source protecting device for an electromotive device

Abstract

A control circuit measures the battery voltage, intermediate voltage and discharge current of a rechargeable battery comprising a plurality of cells connected in series, at prescribed time intervals, and detects values for these parameters based on running averages for a prescribed number of measurement operations, while also detecting the battery temperature. If the battery temperature becomes equal to or greater than a prescribed temperature, or if the discharge current is an excessive current equal to or greater than a prescribed value, or if the battery voltage is equal to or less than a prescribed value, or if it is judged, from detection of the intermediate voltage that the balance between cell capacities has declined, then the control circuit halts discharge from the rechargeable battery by switching an FET to OFF.

Claims22

Dependent claims

A battery power source device comprising:

a rechargeable battery having a discharge circuit;
and
a discharge control device that controls discharge of said rechargeable battery, wherein said discharge control device measures the voltage and discharge current of said rechargeable battery a prescribed number of times at prescribed time intervals, detects a battery voltage value and a discharge current value for each of said prescribed number of measurement operations from running averages for said measurement operations, detects the battery temperature of said rechargeable battery, and shuts off the discharge circuit of said rechargeable battery, when said battery voltage value, discharge current value and battery temperature satisfy any one of the following conditions:
(1) when said battery voltage value at most equal to a predetermined undercut voltage value is detected consecutively for at least a prescribed number of measurement operations;
(2) when said discharge current value at least equal to a predetermined excessive current value is detected consecutively for at least a prescribed number of measurement operations;
and
(3) when said battery temperature is at least equal to a predetermined temperature.

4 more elements

A battery power source device comprising:

a rechargeable battery, in which a discharge circuit is formed, said rechargeable battery comprising a plurality of cells connected in series;
and
a discharge control device that controls discharge of said rechargeable battery, wherein said discharge control device measures unit voltages of each cell and each block of a plurality of cells, and the voltage and discharge current of said rechargeable battery, a prescribed number of times at prescribed time intervals, detects unit voltage values, a battery voltage value and a discharge current value respectively for each of said prescribed number of measurement operations from running averages for said measurement operations, detects the battery temperature of said rechargeable battery, and shuts off the discharge circuit of said rechargeable battery, when said unit voltage values, battery voltage value, discharge current value and battery temperature satisfy any one of the following conditions:
(1) when the difference between the smallest value and the next to smallest value of the respective unit voltage values, which is at least equal to dedetermined allowable value, is consecutively detected for at least a prescribed number of measurement operations;
(2) when said battery voltage value at most equal to a predetermined undercut voltage value is consecutively detected for at least a prescribed number of measurement operations;
(3) when said discharge current value at least equal to a predetermined current value is consecutively detected for at least a prescribed number of measurement operations;
and
(4) when said battery temperature is at least equal to predetermined temperature.

5 more elements

An electromotive device using a battery power source device as a driving power source to drive a motor in rotation, said battery power source device comprising a rechargeable battery having a discharge circuit:

and
a discharge control device that controls discharge of said rechargeable battery, wherein said discharge control device measures a voltage and discharge current of said rechargeable battery a prescribed number of times at prescribed time intervals when said electromotive device is in an ON state, detects a battery voltage value and a discharge current value for each of said prescribed number of measurement operations, from running averages for each of said measurement operations, detects the battery temperature of the rechargeable battery, and shuts off the discharge circuit of the rechargeable battery, when said battery voltage value, discharge current value and battery temperature satisfy any one of the following conditions:
(1) when said battery voltage value at most equal to a predetermined undercut voltage value is detected consecutively for at least a prescribed number of measurement operations;
(2) when said discharge current value at least equal to a predetermined current value is consecutively detected for at least a prescribed number of measurement operations;
and
(3) when said battery temperature is at least equal to a predetermined temperature.

3 more elements

and
a discharge control device that controlls discharge of said rechargeable battery, wherein said discharge control device measures unit voltages of one of each cell and each block of a plurality of cells, and the voltage and discharge current of said rechargeable battery, a prescribed number of times at prescribed time intervals, when said electromotive device is in an ON state, detects unit voltage values, a battery voltage value and a discharge current value for each of said prescribed number of measurement operations from running averages for said measurement operations, detects the battery temperature of the rechargeable battery, and shuts off the discharge circuit of said rechargeable battery, when said unit voltage values, battery voltage value, discharge current value and battery temperature satisfy any one of the following conditions:
(1) when the difference between the smallest value and the next to smallest value of the respective unit voltage values, is at least equal to a predetermined allowable value, is consecutively detected for at least a prescribed number of measurement operations;
(2) when said battery voltage value equal to at most a predetermined undercut voltage value is consecutively detected for at least a prescribed number of measurement operations;
(3) when said discharge current value at least equal to a predetermined current value is consecutively detected for at least a prescribed number of measurement operations;
and
(4) when said battery temperature is at least equal to a predetermined temperature.

4 more elements

Dependencies are inferred from the claim text.

Battery power source protecting device for an electromotive device

Life of this patent

Battery power source protecting device for an electromotive device

Life of this patent

Abstract

Claims22