Charging method and portable electronic device using the same

Patent metadata

Field	Value
Publication number	US-2016218531-A1
Application number	US-201615003779-A
Country	US
Kind code	A1
Filing date	Jan 21, 2016
Priority date	Jan 23, 2015
Publication date	Jul 28, 2016
Grant date	—

Abstract

A charging method of a portable electronic device, adapted to charge a battery module of a portable electronic device, the charging method comprising detecting a battery voltage and a charging current of the battery module; determining whether the portable electronic device operates at a constant current mode according to the battery voltage; entering an over voltage protection charging loop while the portable electronic device operates at the constant current mode and allows the battery module to be charged up at a maximum charging voltage, and leaving the over voltage protection charging loop while the charging current is smaller than a predetermined current, wherein the maximum charging voltage is gradually decreased according to a comparison result between the battery voltage and an overcharging protection voltage; and setting the maximum charging voltage as a full charge voltage while leaving the over voltage protection charging loop.

First claim

What is claimed is:

1 . A charging method of a portable electronic device, adapted to charge a battery module of a portable electronic device, the charging method comprising:
detecting a battery voltage and a charging current of the battery module; determining whether the portable electronic device operates at a constant current mode according to the battery voltage; entering an over voltage protection charging loop while the portable electronic device operates at the constant current mode and allows the battery module to be charged up at a maximum charging voltage, and leaving the over voltage protection charging loop while the charging current is smaller than a predetermined current, wherein the maximum charging voltage is gradually decreased according to a comparison result between the battery voltage and an overcharging protection voltage; and setting the maximum charging voltage as a full charge voltage while leaving the over voltage protection charging loop.

2 . The charging method of the portable electronic device according to claim 1 , wherein the step of entering the over voltage protection charging loop while the portable electronic device operates at the constant current mode and allows the battery module to be charged up at the maximum charging voltage, and leaving the over voltage protection charging loop while the charging current is smaller than the predetermined current further includes:
setting the maximum charging voltage according to the full charge voltage, an impedance compensation voltage, and an impedance compensation coefficient; decreasing the impedance compensation coefficient while the battery voltage is larger than or equal to the overcharging protection voltage, and setting the maximum charging voltage again according to the decreased impedance compensation coefficient, the full charge voltage, and the impedance compensation coefficient; or setting the maximum charging voltage again while the maximum battery voltage is smaller than the overcharging protection voltage; and leaving the over voltage protection charging loop while the charging current is smaller than the predetermined current.

3 . The charging method of the portable electronic device according to claim 2 , wherein the step of decreasing the impedance compensation coefficient while the maximum charging voltage is smaller than or equal to the overcharging protection voltage and setting the maximum charging voltage as the full charge voltage while leaving the over voltage protection charging loop includes:
stopping charging the battery module; determining whether the impedance compensation coefficient is smaller than or equal to a presetting value; decreasing the impedance compensation coefficient by one unit while the impedance compensation coefficient is larger than the presetting value and setting the maximum charging voltage again according to the decreased impedance compensation coefficient, the full charge voltage; and setting the maximum charging voltage while the impedance compensation coefficient is smaller than or equals to the presetting value.

4 . The charging method of the portable electronic device according to claim 2 , wherein the impedance compensation voltage is calculated according to the charging current and a preset compensation impedance.

5 . The charging method of the portable electronic device according to claim 1 , further comprising:
determining whether the battery voltage and the charging current meets a full charge requirement; entering the over voltage protection charging loop again while at least one of the battery voltage and the charging current does not meets the full charge requirement; and stopping charging the battery module while both the battery voltage and the charging current meets the full charge requirement.

6 . The charging method of the portable electronic device according to claim 5 , wherein the step of determining whether the battery voltage and the charging current meet the full charge requirement includes:
determining whether the battery voltage is larger than or equals to the full charge voltage and determining whether the charging current is smaller than a full charge current.

7 . The charging method of the portable electronic device according to claim 1 , wherein the step of determining whether the portable electronic device operates at the constant current mode according to the battery voltage includes:
determining whether the battery voltage is within a preset voltage range.

8 . The charging method of the portable electronic device according to claim 1 , wherein after the portable electronic device is determined to operate at the constant current mode, the charging method further comprises:
executing a soft start before entering the over voltage protection charging loop.

9 . A portable electronic device, comprising:
a function module; a battery module coupled to the function module, configured to charge the function module; and a charging control module coupled to the battery module, configured to charge the battery module, wherein the charging control module detects a battery voltage and a charging current of the battery module and determines whether the portable electronic device operates at a constant current mode according to the battery voltage, while the portable electronic device operates at the constant current mode, the charging control module enters an over voltage protection charging loop and allows the battery module to be charged up at a maximum charging voltage, the charging control module leaves the over voltage protection charging loop while the charging current is smaller than a predetermined current, and the maximum charging voltage is set as a full charge voltage while the over voltage protection charging loop, wherein in the over voltage protection charging loop, the charging control module gradually decreases the maximum charging voltage according to a comparison result between the battery voltage and an overcharging protection voltage.

10 . The portable electronic device according to claim 9 , wherein the charging control module comprises:
a power converting circuit configured to receive a DC power source and convert the DC power source to an operation power source; a power switch coupled to the power converting circuit, configured to receive the operation power source and switch according to a control signal to control the operation power source provided to the battery module; and a control circuit configured to control a power switching of the power converting circuit and provide the control signal to control switching of the power switch, wherein the control circuit detects the battery voltage and the charging current of the battery module to control the control signal according to the detected battery voltage and the detected charging current.

11 . The portable electronic device according to claim 9 , wherein the charging control module sets the maximum charging voltage according to the full charge voltage, an impedance compensation voltage, and an impedance compensation coefficient in the over voltage protection charging loop, and then determines whether the battery voltage is larger than the overcharging protection voltage, while the battery voltage is larger than or equal to the overcharging protection voltage, the charging control module decreases the impedance compensation coefficient to charge the battery module via the corresponding maximum charging voltage.

12 . The portable electronic device according to claim 11 , wherein while the battery voltage is smaller than the overcharging protection voltage, the charging control module determines whether the c

Assignees

• Asustek Comp Inc

Inventors

• Li Ching-Han
• Hung Hsiang-Jui
• Tu Wei-Chen
• Tsai Ming-Ting

Classifications

• H02J7/92

  with prioritisation of loads or sources · CPC title

• H02J7/64

  against overvoltage · CPC title

• H02J7/61 Primary

  against overcharge · CPC title

• H02J7/0057

  Electricity · mapped topic

• H02J7/0029 Primary

  Electricity · mapped topic