Methods and apparatus for simultaneously charging multiple rechargeable batteries

• US 20050189921A1
• Filed: 02/27/2004
• Published: 09/01/2005
• Est. Priority Date: 02/27/2004
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Purdy, Michael L., Bayne, Ryan Mitchell
• Granted Patent: US 7,116,079 B2
• Time in Patent Office: Days
• US Class Current: 320/138
• CPC Class Codes: H02J 2310/22 The load being a portable electronic device
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits

Abstract

A charger has two or more separate charging ports to which two or more rechargeable batteries can be coupled, respectively. Current from a single current source is allocated to the two or more separate charging ports so that the two or more rechargeable batteries will be fully charged at substantially the same time.

Claims

1. A method comprising:

allocating charging currents from a single current source to two or more separate charging ports having two or more rechargeable batteries coupled respectively thereto so that said two or more rechargeable batteries will be fully charged at substantially the same time.

2. The method of claim 1, further comprising:

determining relative amounts of charge required to fully charge said two or more rechargeable batteries.

3. The method of claim 1, further comprising:

determining a charging current allocated to a particular charging port at least in part on an average current drain during usage of the rechargeable battery coupled to said particular charging port.

4. A charger comprising:

a single current source;

two or more separate charging ports;

a current allocator to allocate charging currents from said single current source to said two or more ports; and

a controller to determine said charging currents so that two or more rechargeable batteries coupled respectively to said two or more ports will be fully charged at substantially the same time.

5. The charger of claim 4, further comprising:

a measurement unit to measure voltage differences at said two or more ports; and

one or more lookup tables,

wherein said controller is to determine from said one or more lookup tables an amount of charge required to fully charge a battery based on said measured voltage difference, a battery type, and an average current drain of said battery during usage.

6. The charger of claim 4, wherein a particular one of said rechargeable batteries is inside a battery-operated device and said controller is to receive a voltage of said particular rechargeable battery from said battery-operated device, the charger further comprising:

one or more lookup tables,

wherein said controller is to determine from said one or more lookup tables an amount of charge required to fully charge said particular battery based on said received voltage, a battery type, and an average current drain of said particular battery during usage.