CN111064247A

CN111064247A - Battery state detection method for battery charging

Info

Publication number: CN111064247A
Application number: CN201911309418.XA
Authority: CN
Inventors: 王磊
Original assignee: Southchip Semiconductor Technology Shanghai Co Ltd
Current assignee: Southchip Semiconductor Technology Shanghai Co Ltd
Priority date: 2019-12-18
Filing date: 2019-12-18
Publication date: 2020-04-24

Abstract

The invention discloses a battery state detection method for battery charging, which mainly solves the problem that a power supply chip is possibly burnt due to the fact that the battery state cannot be effectively detected in the battery charging process of the conventional electronic equipment. The battery state detection method of the invention judges whether the battery exists before charging, if the battery exists, the normal charging is carried out, if the battery does not exist, the charging is stopped and the battery state is periodically detected until the battery is correctly inserted to carry out the normal charging process. Avoid charging circuit to produce heavy current in the twinkling of an eye, ensure charging chip's safety, extension battery life. Therefore, the method is suitable for popularization and application.

Description

Battery state detection method for battery charging

Technical Field

The invention relates to the technical field of battery charging, in particular to a battery state detection method for battery charging.

Background

Batteries are an essential part of modern electronic devices, and in many applications, the batteries are removable, whereas the presence of external devices, such as chargers, is not clear. Fig. 1 shows the whole process of charging the battery by the charger. The charger can set different currents to charge the battery according to different voltages of the battery, but the voltage of the battery needs a certain time from different states to the next state. When the battery exists, the battery is equivalent to a large capacitor, and the voltage at the battery end does not change greatly in the conversion time; if the battery is charged when the battery is detached, the charger may not respond in time and may have a large instantaneous current, so that the output voltage of the charger may be instantaneously flushed to a higher value. The chip directly supplying power to the battery terminal may exceed the withstand voltage value, resulting in the burning of the relevant chip.

Disclosure of Invention

The invention aims to provide a battery state detection method for battery charging, which mainly solves the problem that a power supply chip is possibly burnt due to the fact that the battery state cannot be effectively detected in the battery charging process of the conventional electronic equipment.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a battery state detection method for battery charging, comprising the steps of:

(S1) performing a power-on reset or battery voltage triggered charging of the battery charging circuit;

(S2) starting a 10mA current source to discharge the battery, and simultaneously starting a 1S timer;

(S3) when the timer reaches 1S, detecting the battery voltage, judging whether the condition for starting the charging of the charging chip is met or not according to the battery voltage, and if the condition is met, starting the charging chip to normally charge the battery; if not, the step is proceeded to (S4);

(S4) turning off the 10mA current source, turning on the 100mA current source to charge the battery, and simultaneously starting a 0.5S timer;

(S5) when the time is up to 0.5S, the charging current source is closed, the voltage of the battery is detected, whether the charging condition of the charging chip is met or not is judged according to the voltage of the battery, and if the charging condition is met, the charging chip is started to normally charge the battery; if not, the 100mA current source is turned off to stop charging;

(S6) repeating the steps (S2) to (S5) until the charging chip is activated to normally charge the battery.

Further, in step (S3), it is judged whether or not the condition for starting the charging of the charging chip is satisfied: when the timer reaches 1S, whether the battery voltage is less than 2V/node or not is judged, if not, the conditions are met; otherwise, it is not satisfied.

Further, in step (S5), it is judged whether or not the condition for starting the charging of the charging chip is satisfied: when the timer reaches 0.5S, whether the battery voltage is less than 4.2V/node or not is judged, if not, the battery voltage is satisfied; otherwise, it is not satisfied.

Compared with the prior art, the invention has the following beneficial effects:

the invention judges whether the battery exists before charging, if the battery exists, the normal charging is carried out, if the battery does not exist, the charging is stopped and the battery state is periodically detected until the battery is correctly inserted to carry out the normal charging process. Avoid charging circuit to produce heavy current in the twinkling of an eye, ensure charging chip's safety, extension battery life.

Drawings

Fig. 1 is a schematic diagram of a prior art charger charging a battery.

FIG. 2 is a flow chart of a battery status detection method according to the present invention.

Fig. 3 shows the relationship between the battery detection state and the battery terminal voltage at the time of 100mA charging.

Fig. 4 is a relationship between a battery detection state and a battery terminal voltage at the time of starting a discharge current source.

Fig. 5 is a diagram illustrating a battery removal state detection.

Detailed Description

The present invention will be further described with reference to the following description and examples, which include but are not limited to the following examples.

Examples

Referring to fig. 2, in the method for detecting battery state for battery charging according to the present invention, the condition for triggering battery detection is a charging threshold for powering up and triggering battery charging, a 10mA current source is first started to discharge the battery, and a 1S timer is started, and when the timer reaches 1S, it is detected whether the battery voltage is less than 2V/node. If the voltage of the battery is more than 2V/node, the battery is considered to exist, and the charging chip can be started to normally charge the battery. Since the battery may be unused for a long time, the battery itself has been over-discharged, and the battery voltage has been less than 2V/node. Then the 100mA current source is turned on to charge the battery, and simultaneously the 0.5S timer is started, and simultaneously the high voltage at the battery end is prevented from clamping the voltage at the battery end by 4.25V/node. And when the time is up to 0.5S, closing the charging current source, judging whether the voltage of the battery is greater than 4.2V/node, and if the voltage of the battery is greater than 4.2V/node, determining that the battery does not exist. If the voltage of the battery is less than 4.2V, the battery is determined to exist, and the charging circuit is started to normally charge the battery. If the current does not exist, the 100mA current source is closed to stop charging, the 10mA discharging current source is restarted, and the process is repeated until the battery is placed into the battery to be normally charged.

As shown in fig. 3, when the 100mA charging is started, the relationship between the battery detection state and the battery terminal voltage. The battery detection firstly starts a 10mA current source to discharge, because the battery does not exist, a 1S timer is started, when the timer reaches 1S, a 100mA current source is started to charge the battery, a 0.5S timer is started, the voltage rises, the voltage is finally clamped and then 4.25V, and when the 0.5S timer reaches, the charging current source is closed. The power-up process is repeated. Finally, when the battery is in the 100mA charging, 0.5S timer period, the battery is inserted, and when 0.5S is up, the battery voltage is not more than 4.2/node, and the battery is judged to be present.

As shown in fig. 4, the relationship between the battery detection state and the battery voltage when the discharge current source is activated. When the battery is discharged by a 10mA current source, the voltage of the battery is in a 1S timer and cannot be discharged to be below 2V/node, the existence of the battery is judged, and the battery can be charged normally.

As shown in fig. 5, when the battery is suddenly removed during normal charging, the charging circuit will quickly ramp the battery voltage up to the battery full threshold of 4.25/sec, after which the charging circuit will shut down. Due to the self consumption in the charging chip or the self electric quantity consumption of the battery, the battery voltage can be reduced, and when the battery voltage is reduced to 4.2/time, the battery detection is triggered. Starting a 10mA discharge circuit and a timer 1S, and when the battery voltage drops to 2V/section after 1S, considering that the battery does not exist, and repeating the battery detection process.

Through the design, the invention judges whether the battery exists before charging, if the battery exists, the normal charging is carried out, if the battery does not exist, the charging is stopped and the battery state is periodically detected until the battery is correctly inserted to carry out the normal charging process. Avoid charging circuit to produce heavy current in the twinkling of an eye, ensure charging chip's safety, extension battery life. Therefore, the method has high use value and popularization value.

The above-mentioned embodiment is only one of the preferred embodiments of the present invention, and should not be used to limit the scope of the present invention, but all the insubstantial modifications or changes made within the spirit and scope of the main design of the present invention, which still solve the technical problems consistent with the present invention, should be included in the scope of the present invention.

Claims

1. A battery state detection method for charging a battery, comprising the steps of:

2. The battery state detection method for battery charging according to claim 1, wherein in step (S3), the condition for determining whether the charging of the charging chip is started is: when the timer reaches 1S, whether the battery voltage is less than 2V/node or not is judged, if not, the conditions are met; otherwise, it is not satisfied.

3. The battery state detection method for battery charging according to claim 1, wherein in step (S5), the condition for determining whether the charging of the charging chip is started is: when the timer reaches 0.5S, whether the battery voltage is less than 4.2V/node or not is judged, if not, the battery voltage is satisfied; otherwise, it is not satisfied.