Apparatus for refreshing batteries

• US 20030178968A1
• Filed: 03/24/2003
• Published: 09/25/2003
• Est. Priority Date: 03/25/2002
• Status: Active Grant

• Current Assignee: Makita Corporation
• Original Assignee: Makita Corporation
• Inventors: Sakakibara, Kazuyuki, Muramatsu, Tomoo, Okabayashi, Hisakazu
• Granted Patent: US 7,030,590 B2
• Time in Patent Office: Days
• US Class Current: 320/110
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation

Abstract

Battery charger (10) may include a power source circuit (22) for charging rechargeable batteries (58) when a battery pack (50) is connected directly to the battery charger or is connected thereto with an adapter (30) interposed therebetween. The adapter may include a discharging circuit (42) for discharging the rechargeable batteries. The adapter may also include a switch (48) for alternatively connecting the rechargeable batteries with the discharging circuit or the charging circuit of the battery charger. The battery pack may have a memory (61) storing a flag indicating whether a refresh process is required. The adapter may further include a control portion (41) for controlling the switch. When the battery pack has been connected to the battery charger via the adapter, the control portion may preferably controls the switch on the basis of the flag stored in the memory of the battery pack.

Claims

1. An apparatus comprising:

a battery charger comprising a charging circuit for charging rechargeable batteries of a battery pack;

an adapter capable of being connected with the battery pack and the battery charger, the adapter comprising a discharging circuit for discharging the rechargeable batteries, a switch for selectively connecting the rechargeable batteries with the discharging circuit or with the charging circuit of the battery charger when the battery pack is connected with the battery charger via the adapter, and a microprocessor for controlling the switch on the basis of a flag stored in a memory of the battery pack when the battery pack is connected with the battery charger via the adapter, wherein the flag indicates whether a refresh process is required.

2. An apparatus as in claim 1, wherein the battery pack is capable of being connected directly to the battery charger, the battery charger charging the rechargeable batteries of the battery pack when the battery pack has been directly connected to the battery charger.

3. An apparatus as in claim 1, wherein the microprocessor is capable of communicating with the memory of the battery pack, whereby the microprocessor reads the flag from the memory and determines whether the refresh process is required.

4. An apparatus as in claim 1, wherein the memory further stores a total number of charges of the battery pack, wherein the microprocessor determines based upon the total number of charges and the state of the flag whether the refresh process is required.

5. An apparatus as in claim 4, wherein the flag indicates whether the refresh process is required in a first period during a former half of the preset refresh cycle, or a second period during a latter half of the preset refresh cycle, the flag indicating at least six states:

(1) a first state indicating that the refresh process is required in the first period and that the refresh process has not yet been performed;

(2) a second state indicating that the refresh cycle has been performed in the first period;

(3) a third state indicating that the refresh process is not required in the first period;

(4) a fourth state indicating that the refresh process is required in the second period and that the refresh process has not yet been performed;

(5) a fifth state indicating that the refresh process has been performed in the second period;

(6) a sixth state indicating that the refresh process is not required in the second period.

6. An apparatus as in claim 5, wherein the microprocessor performs the following:

(1) if it is determined from the total number of charges that the battery pack is in the first period, and the flag indicates the first state, the fourth state, or the sixth state, the microprocessor causes the refresh process to be performed on the battery pack, and changes the flag to the second state after the refresh process is completed;

(2) if it is determined from the total number of charges that the battery pack is in the first period, and the flag indicates the fifth state, the microprocessor changes the flag to the third state;

(3) if it is determined from the total number of charges that the battery pack is in the second period, and the flag indicates the first state, the third state, or the fourth state, the microprocessor causes the refresh process to be performed on the battery pack, and changes the flag to the fifth state after the refresh process is completed;

(4) if it is determined from the total number of charges that the battery pack is in the second period, and the flag indicates the second state, the microprocessor changes the flag to the sixth state.

7. An adapter comprising:

a first electrical contact capable of connecting with rechargeable batteries of a battery pack;

a second electrical contact capable of connecting with a charging circuit of a battery charger;

a discharging circuit for discharging the rechargeable batteries;

a switch selectively connecting the first electrical contact with either the discharging circuit or with the second electrical contact;

a microprocessor electrically connecting the switch and a memory of the battery pack, the memory stores a flag indicating whether the refresh process is required, wherein the microprocessor reads a flag from the memory and controls the switch on the basis of the read flag when the rechargeable batteries has been connected with the first electrical contact and the charging circuit has been connected with the second electrical contact.