Battery pack and method of protecting battery pack

Patent metadata

Field	Value
Publication number	US-11876190-B2
Application number	US-202017022193-A
Country	US
Kind code	B2
Filing date	Sep 16, 2020
Priority date	Sep 27, 2019
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

A battery pack in one aspect of the present disclosure includes a battery and a controller provided with a counter value. During discharge of the battery pack, the controller calculates an addition value in accordance with a total number of use of the battery pack under a specified condition. The controller updates the counter value by adding the addition value. The controller prohibits the discharge of the battery pack in response to the counter value reaching a protection threshold.

First claim

What is claimed is:

1. A battery pack comprising:
a battery;
a memory storing a map A 1 and a map B 1 , the map A 1 and the map B 1 each indicating a correspondence relation between a discharge current value and an addition value, the addition value in the map B 1 being larger than the addition value in the map A 1 ;
a signal terminal; and
a Main Control Unit (MCU) including an overcurrent counter value and a history counter value,
the MCU being configured to perform a discharge prohibition determination process, the discharge prohibition determination process including:
obtaining the discharge current value in response to an electric working machine being connected to the battery pack;
calculating the addition value corresponding to the discharge current value obtained, by using the map A 1 in response to the history counter value being equal to or less than a setting value;
calculating the addition value corresponding to the discharge current value obtained, by using the map B 1 in response to the history counter value being more than the setting value;
updating the overcurrent counter value by adding the addition value calculated to the overcurrent counter value;
turning ON an overload determination flag increasing the history counter value in response to the overcurrent counter value reaching an overload threshold; and
outputting a discharge prohibition signal via the signal terminal in response to the overcurrent counter value reaching a protection threshold larger than the overload threshold.

2. A battery pack comprising:
a battery; and
a controller provided with a counter value, the controller being configured to:
calculate an addition value during discharge of the battery in accordance with a total number of uses of the battery pack under a specified condition;
update the counter value by adding the addition value during the discharge of the battery; and
prohibit the discharge of the battery during the discharge of the battery in response to the counter value reaching a protection threshold,

the total number of uses including a first number of operations,
the first number of operations corresponding to a total number of operations of the battery pack having the counter value exceeding an overload threshold, and
the overload threshold being set to be smaller than the protection threshold.

3. The battery pack according to claim 2 ,
wherein the controller is configured to calculate the addition value so that the addition value increases in response to the total number of uses increasing.

4. The battery pack according to claim 2 ,
wherein the controller is configured to calculate the addition value that is zero or more in accordance with a discharge current value being equal to or more than a specified value, and
wherein the controller is configured to calculate the addition value that is zero or less in accordance with the discharge current value being less than a specified value.

5. The battery pack according to claim 2 ,
wherein the total number of uses includes a second number of operations, and
wherein the second number of operations corresponds to a total number of operations of the battery pack having a temperature exceeding a specified temperature threshold.

6. The battery pack according to claim 2 ,
wherein the controller is configured to calculate a subtraction value in accordance with the total number of uses during charge of the battery,
wherein the subtraction value is less than zero, and
wherein the controller is configured to update the counter value by adding the subtraction value during the charge of the battery.

7. The battery pack according to claim 6 ,
wherein the controller is configured to calculate the subtraction value so that the subtraction value increases in response to the total number of uses increasing.

8. The battery pack according to claim 2 ,
wherein the controller is configured to set the protection threshold during the discharge of the battery in accordance with the total number of uses.

9. The battery pack according to claim 8 ,
wherein the controller is configured to set the protection threshold so that the protection threshold decreases in response to the total number of uses increasing.

10. The battery pack according to claim 2 ,
wherein the controller is configured to set the overload threshold during the discharge of the battery in accordance with the total number of uses.

11. The battery pack according to claim 10 ,
wherein the controller is configured to set the overload threshold so that the overload threshold decreases in response to the total number of uses increasing.

12. A battery pack comprising:
a battery; and
a controller provided with a counter value, the controller being configured to:
calculate an addition value during discharge of the battery in accordance with a total number of uses of the battery pack under a specified condition;
update the counter value by adding the addition value during the discharge of the battery;
prohibit the discharge of the battery during the discharge of the battery in response to the counter value reaching a protection threshold; and
increase the total number of uses during the charge of the battery, in response to a loaded state of the battery satisfying a specified condition between a previous charge to this charge.

13. A method of protecting a battery included in a battery pack, the method comprising:
calculating an addition value in accordance with a total number of uses of the battery during discharge of the battery, the total number of uses including a first number of operations, the first number of operations corresponding to a total number of operations of the battery pack having a counter value exceeding an overload threshold, and the overload threshold being set to be smaller than a protection threshold;
updating the counter value by adding the addition value during the discharge of the battery; and
prohibiting the discharge of the battery in response to the counter value reaching the protection threshold during the discharge of the battery.

Assignees

• Makita Corp

Inventors

• Kobayakawa Tadahiko
• Uesugi Hiroki
• Kano Hayato

Classifications

• H02J7/977

  of the battery · CPC title

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02J7/865

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H02J7/62

  against overcurrent · CPC title

• H02J7/65

  against overtemperature · CPC title