Charging control method and charging assembly

A charging assembly and a charging control method are provided for charging a battery pack according to an actual voltage of a battery in a battery pack. The charging assembly includes a battery pack having a battery with a rated charging current, a charger having a charging module for outputting an output voltage and an output current, and a charging circuit between the charging module and the battery. A method of operation includes: detecting the output current and the output voltage; calculating an actual voltage value on the battery; and determining whether to decrease or keep the output current or increase the output current of the charging module.

RELATED APPLICATION INFORMATION

This application claims the benefit of CN 201310733942.6, filed on Dec. 26, 2013, the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to charging control methods and charging assemblies.

BACKGROUND OF THE DISCLOSURE

As types of chargers available in the market are increasing, competition between products gets intensified. The length of the charging duration of chargers with the same power is directly associated with user experience, so there is a pressing need to improve the charging efficiency.

The charging procedure of an ordinary charger comprises two phases, namely, a constant-current phase and a constant voltage phase. According to a control method employed by an ordinary charger, due to inaccuracy of detection and compensation method, a constant preset charging voltage cannot be accurately applied on a battery cell assembly in the constant voltage phase of the charging procedure so that the battery cell assembly is always charged with a voltage smaller than the preset charging voltage, thus the charging efficiency is reduced relative to a preset time.

SUMMARY

In one aspect of the disclosure, a charging assembly is provided for increasing charging efficiency. The charging assembly comprises a battery pack comprising a battery with a rated charging current, a charger comprising a charging module for outputting an output voltage and an output current, and a charging circuit between the charging module and the battery.

Preferably, the charger further comprises a control module electrically connected with the charging module, a voltage detecting module for detecting the output voltage of the charging module, and a current detecting module for detecting the output current of the charging module.

The voltage detecting module and the current detecting module are electrically connected to the control module; the charging module is capable of applying a charging voltage on the battery, and the control module is capable of controlling the charging module to adjust the charging voltage on the battery according to an equivalent resistance value of the charging circuit between the charging module and the battery.

Preferably, the charging circuit comprises a first charging circuit for connecting the charging module to the positive electrode of the battery, and a second charging circuit for connecting the charging module to the negative electrode of the battery.

Furthermore, the first charging circuit may comprise a first charger circuit in the charger and a first battery circuit in the battery pack; and the second charging circuit comprises a second charger circuit in the charger and a second battery circuit in the battery pack.

Furthermore, the control module may be provided with a self-check mode which is capable of detecting equivalent resistance value of the first charger circuit and the second charger circuit by controlling the voltage detecting module and the current detecting module when the first charger circuit and the second charger circuit connected with each other by a user.

In another aspect of the disclosure, a charging control method is provided for controlling the assembly described above. The method comprises: detecting the output current value I1and the output voltage value U1of the charging module; calculating an actual voltage value U2on the battery according to U2=U1−I1×R, wherein R is a equivalent resistance value of a charging circuit between the charging module and the battery; determining whether the actual voltage value U2is higher than or equal to a preset charging voltage value; if yes, decreasing or keeping the output current of the charging module; if no, increasing the output current of the charging module.

The drawings described herein are for illustrative purposes only of exemplary embodiments and not all possible implementations, and are not intended to limit the scope of the claims hereinafter presented. Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the scope of the invention as claimed, its application, or uses.

As shown inFIG. 1, an exemplary charging assembly100mainly comprises a battery pack10, a charger20and a charging circuit30.

The battery pack10comprises a battery11with a rated charging current. The battery11consists of at least one battery cell111.

The charger20comprises a charging module21for outputting an output voltage and an output current, a control module22electrically connected with the charging module21, a voltage detecting module23for detecting the output voltage of the charging module21, and a current detecting module24for detecting the output current of the charging module21.

The voltage detecting module23and the current detecting module24are electrically connected to the control module22; the charging module21is capable of applying a charging voltage on the battery11, and the control module22is capable of controlling the charging module21to adjust the charging voltage on the battery11according to an equivalent resistance value of the charging circuit30between the charging module21and the battery11.

Preferably, the control module22comprises a MCU chip with a clock frequency is in a range of 32 KHz-24 MHz.

Preferably, the charging circuit30between the charging module21and the battery11comprises a first charging circuit31for connecting the charging module21to the positive electrode of the battery11and a second charging circuit32for connecting the charging module21to the negative electrode of the battery11.

Specifically, the first charging circuit31comprises a first charger circuit311in the charger20and a first battery circuit312in the battery pack10; and the second charging circuit32comprises a second charger circuit321in the charger20and a second battery circuit322in the battery pack10.

The equivalent resistance value of the charging circuit30is to be detected and stored in the control module22when the charger20and the battery pack10are fabricated.

In another way, the control module22is provided with a self-check mode which is capable of detecting an equivalent resistance value of the first charger circuit311and the second charger circuit321by controlling the voltage detecting module23and the current detecting module24when the first charger circuit311and the second charger circuit321are connected with each other by a user.

Generally, the equivalent resistance value of the first battery circuit312and the second circuit is far less than the equivalent resistance value of the first charger circuit311and the second charger circuit321, so the self-check mode is provided for collecting a data of an equivalent resistance value which is approximately equal to the actual equivalent resistance value of the charging circuit30between the charging module21and the battery11.

As shown inFIG. 2, an exemplary charging control method comprises the following steps:

S1: detecting the output current value I1and the output voltage value U1of the charging module21by a current detecting module24and a voltage detecting module23.

S2: calculating an actual voltage value U2on the battery11according to U2=U1−I1×R by a control module22, wherein R is an equivalent resistance value of a charging circuit30between the charging module21and the battery11which is stored in the control module22.

S3: determining whether the actual voltage value U2is higher than a preset charging voltage value by the control module22, and proceeding to step S4if yes, or proceeding to step S5if no.

S4: decreasing the output current of the charging module21, and returning to step S1.

S5: determining whether the actual voltage value U2is equal to the preset charging voltage value by the control module22, keeping the output current of the charging module21and returning to step S1if yes, or proceeding to step S6if no.

S6: increasing the output current of the charging module21, and returning to step S1.

Preferably, the output current of the charging module21is decreased by 0.3%-10% of the rated charging current every time in step S4by the control module22, and the output current of the charging module21is increased by 0.3%-10% of the rated charging current every time in step S6by the control module22.

As shown inFIG. 3, another exemplary charging control method comprises the following steps:

S1: detecting the output current value I1and the output voltage value U1of the charging module21by a current detecting module24and a voltage detecting module23.

S2: calculating an actual voltage value U2on the battery11according to U2=U1−I1×R by a control module22, wherein R is an equivalent resistance value of a charging circuit30between the charging module21and the battery11which is stored in the control module22.

S3: determining whether the actual voltage value U2is higher than a preset charging voltage value by the control module22, and proceeding to step S4if yes, or proceeding to step S5if no.

S4: decreasing the output current of the charging module21, and returning to step S1.

According to the above methods, the effect of charging with the preset charging voltage can be accurately achieved even in a dynamic charging procedure.

Experimentation was carried out on several sets of identical charger20sand battery pack10s, with identical power quantity standard as full-charge standard. By comparing the method according to the above embodiment with the ordinary charging method with the preset charging voltage value U, the time saved by the method according to the present invention is about 20% of the total time used by the ordinary charging method. Therefore, the method of the present invention can effectively reduce the charging time and improve the charging efficiency.

The above illustrates and describes basic principles, main features and advantages of the present invention. Those skilled in the art should appreciate that the above embodiments do not limit the present invention in any form. Technical solutions obtained by equivalent substitution or equivalent variations all fall within the scope of the present invention.