CHARGER SYSTEM FOR RECHARGEABLE LITHIUM BATTERIES UTILIZING POWER SUPPLY TERMINAL AS INITIAL CHARGING MEANS, AND COMPLETING CHARGING VIA INTERNAL CONSTANT-VOLTAGE CHARGER

• US 20100090662A1
• Filed: 01/16/2009
• Published: 04/15/2010
• Est. Priority Date: 10/09/2008
• Status: Abandoned Application

• Current Assignee: Celxpert Energy Limited, Advance Smart Industrial Limited (Celxpert Holdings Ltd.)
• Original Assignee: Celxpert Energy Limited, Advance Smart Industrial Limited (Celxpert Holdings Ltd.)
• Inventors: OKUTO, Tadashi
• Application Number:
  US12/354,858
• Publication Number:
  US 20100090662A1
• Time in Patent Office: Days
• US Class Current: 320/164
• CPC Class Codes: H02J 7/0018 using separate charge circuits

Abstract

The present invention discloses a charger system for rechargeable lithium batteries, which comprises a power supply terminal, a first switch device, a second switch device, a charging unit, a DC/DC converter, and a controller. The power supply terminal provides power with two ends thereof respectively coupled to the first switch device and a protection circuit. The first switch device is coupled to the second switch device. The first switch device and the second switch device are respectively coupled to the protection circuit. The charging unit is coupled to the protection circuit and the second switch device and has a plurality of charging bays. The charging bays respectively receive lithium batteries and are respectively parallel coupled to constant-voltage chargers to charge the lithium batteries. The DC/DC converter is coupled to the constant-voltage chargers. The controller is coupled to the DC/DC converter, the charging unit and the protection circuit respectively.

Claims

1. A charger system for rechargeable lithium batteries, comprising:

a power supply terminal providing power;

a first switch device coupled to a second switch device, wherein said first switch device and said second switch device are respectively coupled to a protection circuit and power supply terminal;

a charging unit coupled to said protection circuit and said second switch device, having a plurality of charging bays, wherein said charging bays respectively receive lithium batteries and are respectively coupled to constant-voltage chargers to charge said lithium batteries;

a DC/DC converter coupled to said constant-voltage chargers;

a controller coupled to said DC/DC converter, said charging unit and said protection circuit respectively; and

the controller monitors the voltages of the lithium batteries and controls the DC/DC converter to charge the lithium batteries,

wherein the second switch device is turned off when one of said lithium batteries reaches a voltage of 4.2V, and each of all said constant-voltage chargers charges a corresponding one of said lithium batteries until said corresponding one of said lithium batteries reaches a voltage of 4.2V.

2. The charger system for rechargeable lithium batteries according to claim 1, which applies to portable computers, portable multimedia players, mobile phones, and lithium battery chargers.

3. The charger system for rechargeable lithium batteries according to claim 2, wherein said controller is coupled to a portable computer and shows residual capacities of lithium batteries on a screen of said portable computer.

4. The charger system for rechargeable lithium batteries according to claim 1, wherein said first switch device and said second switch device are metal oxide semiconductor field effect transistors (MOSFET).

5. A method of recharging lithium batteries, comprising,

charging the lithium batteries by an external charger;

charging the lithium batteries by internal chargers when any one of said lithium batteries reaches a voltage of 4.2V charged by the external charger.