Charge control device, battery pack, and charger

Patent metadata

Field	Value
Publication number	US-9784795-B2
Application number	US-201514741788-A
Country	US
Kind code	B2
Filing date	Jun 17, 2015
Priority date	Jun 23, 2014
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A charge control device of one example of the present invention comprises a temperature detection unit, a storage unit, and an upper limit setting unit. The storage unit stores a reference current characteristic and at least one of a first current characteristic and a second current characteristic as a charging current characteristic, and stores a reference voltage characteristic and at least one of a first voltage characteristic and a second voltage characteristic as a charging voltage characteristic. The upper limit setting unit selects a characteristic used to set upper limits of a charging current and a charging voltage to the battery from among a plurality of the charging current characteristics and a plurality of the charging voltage characteristics stored in the storage unit.

First claim

What is claimed is:

1. A charge control device comprising:
a temperature detection unit that detects a battery temperature;
a storage unit that stores a charging current characteristic indicating relationships between the battery temperature and an upper limit of a charging current, and a charging voltage characteristic indicating relationships between the battery temperature and an upper limit of a charging voltage; and
an upper limit setting unit that sets each of the upper limits of the charging current and the charging voltage from a charger to a battery on a basis of the battery temperature detected by the temperature detection unit and the charging current characteristic and the charging voltage characteristic stored in the storage unit,
wherein the storage unit stores, as the charging current characteristic, a reference current characteristic and at least one of a first current characteristic having a current value larger than that in the reference current characteristic with respect to the battery temperature and a second current characteristic having a current value smaller than that in the reference current characteristic with respect to the battery temperature, and also stores, as the charging voltage characteristic, a reference voltage characteristic and at least one of a first voltage characteristic having a voltage value larger than that in the reference voltage characteristic with respect to the battery temperature and a second voltage characteristic having a voltage value smaller than that in the reference voltage characteristic with respect to the battery temperature, and
wherein the upper limit setting unit selects the charging current characteristic and the charging voltage characteristic used to set the upper limits of the charging current and the charging voltage to the battery from among a plurality of the charging current characteristics and a plurality of the charging voltage characteristics stored in the storage unit.

2. The charge control device according to claim 1 ,
wherein the upper limit setting unit selects the charging current characteristic and the charging voltage characteristic on a basis of a parameter related to a value of the charging current from the charger to the battery.

3. The charge control device according to claim 2 ,
wherein the upper limit setting unit selects the charging current characteristic and the charging voltage characteristic on a basis of a value of an outputtable current capable of being supplied from the charger to the battery.

4. The charge control device according to claim 3 ,
wherein the upper limit setting unit selects, as the charging current characteristic and the charging voltage characteristic, the first current characteristic and the second voltage characteristic in a case where the value of the outputtable current is larger than the upper limit of the charging current obtained on a basis of the battery temperature detected by the temperature detection unit and the reference current characteristic stored in the storage unit.

5. The charge control device according to claim 1 ,
wherein, in the first current characteristic and the first voltage characteristic, a temperature range in which the upper limits of the charging current and the charging voltage are set to permit charging is wider than a temperature range in the reference current characteristic and the reference voltage characteristic.

6. The charge control device according to claim 5 ,
wherein, in a case where the upper limit setting unit selects, as the charging current characteristic and the charging voltage characteristic, the first current characteristic and the first voltage characteristic, respectively, and sets the upper limits of the charging current and the charging voltage within a temperature range other than the temperature range in the reference current characteristic and the reference voltage characteristic on a basis of the selected first current characteristic, the selected first voltage characteristic, and the battery temperature detected by the temperature detection unit, the upper limit setting unit informs a user of that effect.

7. The charge control device according to claim 1 , comprising a first charge prohibition unit that prohibits the charger from charging the battery in a case where a value of an outputtable current capable of being supplied from the charger to the battery is equal to or larger than the upper limit of the charging current obtained on a basis of the battery temperature detected by the temperature detection unit and the first current characteristic.

8. The charge control device according to claim 7 , comprising a second charge prohibition unit that prohibits the charger from charging the battery in a case where the value of the outputtable current is not acquired.

9. The charge control device according to claim 7 , comprising a charge permission unit that permits the charger to charge the battery by setting values set in advance as the upper limits of the charging current and the charging voltage in a case where the value of the outputtable current is not acquired, provided that the battery temperature detected by the temperature detection unit is within a specified chargeable temperature range.

10. The charge control device according to claim 1 , comprising a determination unit that determines a temperature range of the battery temperature in which charging of the battery is started, on a basis of the value of the outputtable current capable of being supplied from the charger to the battery and the first current characteristic.

11. The charge control device according to claim 10 ,
wherein the storage unit is provided to the battery, and the determination unit is provided to the charger, and
wherein the determination unit acquires the first current characteristic from the storage unit provided to the battery and determines the temperature range.

12. The charge control device according to claim 2 ,
wherein the upper limit setting unit detects an actual charging current supplied from the charger to the battery, compares a value of the detected actual charging current with the upper limit of the charging current under a present temperature condition obtained from each charging current characteristic, and selects the charging voltage characteristic suitable for passage of the actual charging current on a basis of a comparison result.

13. The charge control device according to claim 12 ,
wherein the upper limit setting unit selects, as the charging voltage characteristic, the second voltage characteristic having the lowest upper limit of the charging voltage when charging of the battery by the charger is started.

14. The charge control device according to claim 13 ,
wherein the upper limit setting unit selects, as the charging voltage characteristic, the second voltage characteristic in a case where the battery temperature detected by the temperature detection unit is within a specified chargeable temperature range to cause the charger to start charging the battery, and subsequently, selects the charging voltage characteristic using the value of the actual charging current, thereby to set the upper limit of the charging voltage and to extend a temperature range in which charging of the battery is performed.

15. A battery pack comprising:
a battery; and
a charge control device comprising:
a temperature detection unit that detects a battery temperature;
a storage unit that stores a charging current characteristic indicating relationships between the battery temperature and an upper limit of a charging current, and a charging voltage characteri

Assignees

• Makita Corp

Inventors

• Umemura Takuya
• Kobayakawa Tadahiko
• Suzuki Hitoshi

Classifications

• H02J7/875

  Charging or discharging for charge maintenance, battery initiation or rejuvenation · CPC title

• H02J7/731

  specially adapted for holding portable devices containing batteries (H02J7/751 takes precedence) · CPC title

• H02J7/485

  with provisions for charging different types of batteries · CPC title

• H02J7/445

  in response to measured battery parameters, e.g. voltage, current or temperature profile · CPC title

• H02J7/92

  with prioritisation of loads or sources · CPC title