Battery charging method and apparatus therefor

• US 20050285568A1
• Filed: 06/25/2004
• Published: 12/29/2005
• Est. Priority Date: 06/25/2004
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Froding, Emil, Jorgensen, Frank, Hansen, Stig Rafn
• Granted Patent: US 7,301,307 B2
• Time in Patent Office: Days
• US Class Current: 320/128
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence

Abstract

By determining charging current I_char and then subsequently utilising that determination of charging current I_char in relation to battery current I_bat and load current I_load as a result of operation of a phone or other electronic device it is possible periodically to adjust the necessary charging current in order to operate the device in terms of recharging the battery to a target charging voltage, as well as providing adequate electrical current for operation of the associated phone or other electronic device.

Claims

1. A battery charging method for a portable hand held device, the method comprising applying a charging current across a battery for charging of the battery to attain a charging voltage and determination of load current by periodic interruption in application of the charging current whereby the charging current for the battery is adjusted towards a defined target value for the charging voltage between determinations of the load current for sustained charging of the battery despite variation in load current requirements.

2. A method as claimed in claim 1 wherein the adjustment towards the defined target value is for consistent battery charging irrespective of load current requirements.

3. A method as claimed in claim 2 wherein charging voltage is maintained up to a pre-determined limit value for the load current.

4. A method as claimed in claim 1 wherein the periodic interruption is in the order of every sixty seconds.

5. A method as claimed in claim 1 wherein the interruption lasts for a time period of one second.

6. A method as claimed in claim 1 wherein the charging current is applied by pulse width modulation (PWM) of that current.

7. A method as claimed in claim 1 wherein the method is only performed upon attainment of a minimum battery charge voltage by the battery for subsequently further charging of the battery to a target value for the charging voltage.

8. A battery charging apparatus comprising means to couple a battery to the apparatus, means to apply a charging current to the battery to attach a charging voltage and means to determine load current by periodic interruption in the application of the charging voltage whereby the charging current is adjusted towards a defined target value for the charging voltage between determinations of the battery load current.