TWI901111B - Charging apparatus - Google Patents

Abstract

A charging apparatus functions in charging a rechargeable battery system, and includes a AC/DC converter, a controller, a DC output unit and a communication unit. The communication unit functions in receiving a current state of health (SOH) percentage and a current state of charge (SOC) percentage associated with the rechargeable battery system. The controller determines a selected SOC percentage from a plurality of predetermined SOC percentages in accordance with the current SOH percentage and a relationship stored therein. The controller controls the AC/DC converter to covert an AC power into a charging DC, and to output the charging DC to the DC output unit to charge the rechargeable battery system until the current SOC percentage equals the selected SOC percentage.

Description

Charging device

The present invention relates to a charging device for charging a rechargeable battery system, and more particularly to a charging device capable of automatically adjusting a selected battery state of charge (SOC) percentage to charge the rechargeable battery system.

Regarding the charging of rechargeable battery systems such as lithium-ion batteries, the optimal battery capacity for current rechargeable battery systems falls between 20% and 80%. Factors that affect the service life of rechargeable battery systems are temperature and charge capacity. In terms of charge capacity and taking lithium-ion batteries as an example, most current rechargeable battery systems set the single charge capacity at 80%. This is because the service life of a rechargeable battery system when the charge capacity is reached to 80% is nearly five times that of a rechargeable battery system when the charge capacity is reached to 100%. Please refer to Figure 1, which is a charging curve diagram of a rechargeable battery system in the prior art, showing the relationship between the battery state of charge (SOC) and the battery state of health (SOH) of the rechargeable battery system. As shown in Figure 1, as the battery state of health (SOH) percentage of a rechargeable battery system falls below 100%, the optimal battery capacity of the rechargeable battery system also changes.

However, current charging devices charge rechargeable battery systems to a predetermined battery state of charge percentage each time, for example, the SOC percentage is set to 80%.

Therefore, one of the technical problems to be solved by the present invention is to provide a charging device that can automatically adjust the selected battery state of charge percentage to charge a rechargeable battery system. In this way, the service life of the rechargeable battery system can be increased.

According to the first preferred embodiment of the present invention, the charging device is used to charge a rechargeable battery system. The rechargeable battery system includes a battery management system and a first communication unit. The first communication unit is electrically connected to the battery management system. The battery management system calculates the current battery health status percentage and the current battery charge status percentage of the rechargeable battery system. According to the first preferred embodiment of the present invention, the charging device includes an AC/DC converter, a controller, a DC output unit and a second communication unit. The AC/DC converter is used to receive AC power. The controller is electrically connected to the AC/DC converter. The controller stores therein a relationship between a plurality of predetermined battery charge status percentages and a plurality of predetermined battery health status percentages. The DC output unit is electrically connected to the AC/DC converter and the controller, respectively. The DC output unit is also electrically connected to the rechargeable battery system via a cable. The controller controls the DC output unit to turn on or off. The second communication unit is electrically connected to the controller. The second communication unit can communicate with the first communication unit and is used to receive the current battery health status percentage and the current battery charge status percentage via the first communication unit. The controller determines the selected battery charge status percentage from a plurality of predetermined battery charge status percentages based on the current battery health status percentage and a relationship. The controller controls the AC/DC converter to convert AC power into charging DC power and transmit it to the DC output unit. The controller also controls the DC output unit to output charging DC power to charge the rechargeable battery system until the current battery state of charge percentage is equal to the selected battery state of charge percentage.

Furthermore, the charging device according to the first preferred embodiment of the present invention further includes a detection unit. The detection unit is electrically connected to the controller and electrically coupled to the cable. The detection unit is used to detect the charging voltage and charging current. The controller controls the DC output unit to adjust the output voltage and current of the charging DC power based on the charging voltage and charging current.

In one embodiment, the relationship is stored in the controller in the form of a lookup table.

According to the second preferred embodiment of the present invention, a charging device is used to charge a rechargeable battery system. The rechargeable battery system includes a battery management system and a first communication unit. The first communication unit is electrically connected to the battery management system. The battery management system calculates the current battery charge status percentage of the rechargeable battery system. According to the second preferred embodiment of the present invention, a charging device includes an AC/DC converter, a controller, a DC output unit, and a second communication unit. The AC/DC converter is used to receive AC power. The controller is electrically connected to the AC/DC converter. The DC output unit is electrically connected to the AC/DC converter and the controller, respectively. The DC output unit is also electrically connected to the rechargeable battery system via a cable. The controller controls the DC output unit to turn on or off. The second communication unit is electrically connected to the controller. The second communication unit can communicate with the first communication unit and is used to receive the current battery state of charge percentage via the first communication unit. The controller determines whether the number of times the first selected battery state of charge percentage is selected is equal to N based on a plurality of previous charging information, where N is an integer greater than 1. If the controller determines that the number of times the first selected battery state of charge percentage is selected is equal to N, the controller determines the second selected battery state of charge percentage and controls the AC/DC converter to convert AC power into charging DC power and transmit it to the DC output unit. The controller also controls the DC output unit to output charging DC power to charge the rechargeable battery system until the current battery state of charge percentage is equal to a second selected battery state of charge percentage. The second selected battery state of charge percentage is greater than the first selected battery state of charge percentage.

Furthermore, if the controller determines that the first selected battery state of charge percentage has been selected a number of times less than N, the controller controls the AC/DC converter to convert AC power into charging DC power and transmit it to the DC output unit, and controls the DC output unit to output the charging DC power to charge the rechargeable battery system until the current battery state of charge percentage equals the first selected battery state of charge percentage.

Furthermore, the battery management system detects a battery cell pressure difference of the rechargeable battery system. The second communication unit can be used to receive the battery cell pressure difference via the first communication unit. The controller also determines whether the battery cell pressure difference is equal to or greater than a first threshold value. If the controller determines that the battery cell pressure difference is equal to or greater than the first threshold value, the controller determines a second selected battery state of charge percentage and controls the AC/DC converter to convert AC power into charging DC power and transmit it to the DC output unit to charge the rechargeable battery system until the battery cell pressure difference is less than the second threshold value and the current battery state of charge percentage is equal to the second selected battery state of charge percentage.

The charging device according to the third preferred embodiment of the present invention is used to charge a rechargeable battery system. The charging device according to the third preferred embodiment of the present invention includes an AC/DC converter, a controller, a DC output unit, a detection unit, and a selection unit. The AC/DC converter is used to receive AC power. The controller is electrically connected to the AC/DC converter. The controller stores therein a relationship between a plurality of predetermined charging voltages, a plurality of predetermined charging currents, and a plurality of predetermined battery charge status percentages. The DC output unit is electrically connected to the AC/DC converter and the controller, respectively. The DC output unit is also electrically connected to the rechargeable battery system via a cable. The controller turns the DC output unit on and off. The detection unit is electrically connected to the controller and electrically coupled to the cable. The detection unit is used to detect charging voltage and charging current. The selection unit is electrically connected to the controller. The selection unit is operated by a user to input a command. In response to the command, the controller determines a selected battery state-of-charge percentage and determines the current battery state-of-charge percentage from a plurality of predetermined battery state-of-charge percentages based on the charging voltage, charging current, and a relationship. The controller controls the AC/DC converter to convert AC power into charging DC power and transmit it to the DC output unit, and controls the DC output unit to output the charging DC power to charge the rechargeable battery system until the current battery state of charge percentage is equal to the selected battery state of charge percentage.

In one embodiment, the relationship is stored in the controller in the form of a lookup table.

Unlike prior art, the charging device of the present invention can automatically adjust the selected battery state of charge percentage to charge the rechargeable battery system. Thus, by using the charging device of the present invention to charge the rechargeable battery system, the service life of the rechargeable battery system can be increased.

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the accompanying drawings.

Please refer to FIG2 , which schematically shows the structure of a charging device 1 and a rechargeable battery system 2 charged by the charging device 1 according to the first preferred embodiment of the present invention.

As shown in FIG2 , a charging device 1 according to a first preferred embodiment of the present invention is used to charge a rechargeable battery system 2. Rechargeable battery system 2 includes a battery management system 20 and a first communication unit 22. First communication unit 22 is electrically connected to battery management system 20. Battery management system 20 calculates the current battery state of health (SOH) percentage and the current battery state of charge (SOC) percentage of rechargeable battery system 2.

As shown in FIG2 , the charging device 1 according to the first preferred embodiment of the present invention includes an AC/DC converter 10 , a controller 12 , a DC output unit 14 , and a second communication unit 16 .

The AC/DC converter 10 is used to receive AC power. The controller 12 is electrically connected to the AC/DC converter 10. The controller 12 stores therein a relationship between a plurality of predetermined battery state of charge percentages and a plurality of predetermined battery health status percentages.

The DC output unit 14 is electrically connected to the AC/DC converter 10 and the controller 12. The DC output unit 14 is also electrically connected to the rechargeable battery system 2 via a cable 15. The controller 12 controls the DC output unit 14 to turn on and off. The second communication unit 16 is electrically connected to the controller 12. The second communication unit 16 is capable of communicating with the first communication unit 22 and is used to receive the current battery health percentage and the current battery charge percentage via the first communication unit 22.

The controller 12 determines a selected battery state of charge percentage from a plurality of predetermined battery state of charge percentages based on the current battery state of health percentage and a relationship. The controller 12 controls the AC/DC converter 10 to convert AC power into charging DC power and transmit it to the DC output unit 14. The controller 12 also controls the DC output unit 14 to output the charging DC power, thereby charging the rechargeable battery system 2 until the current battery state of charge percentage equals the selected battery state of charge percentage. This increases the service life of the rechargeable battery system 2.

Furthermore, the charging device 1 according to the first preferred embodiment of the present invention further includes a detection unit 18. The detection unit 18 is electrically connected to the controller 12 and electrically coupled to the cable 15. The detection unit 18 is used to detect the charging voltage and charging current. The controller 12 controls the DC output unit 14 to adjust the output voltage and current of the charging DC power based on the charging voltage and charging current.

In one embodiment, the relationship is stored in the controller 12 in the form of a lookup table. In another embodiment, the relationship is stored in the controller 12 in the form of an equation. An example of a relationship in the form of a lookup table is shown in Table 1.

Table 1 Predetermined SOH percentage Predetermined SOC percentage 100% 80% 95% 85% 90% 90% 85% 95% 80% 100%

According to the example shown in Table 1, when the current SOH percentage is 100%, the controller 12 determines the selected SOC percentage to be 80%. When the current SOH percentage is 90%, the controller 12 determines the selected SOC percentage to be 90%. When the current SOH percentage is 80%, the controller 12 determines the selected SOC percentage to be 100%.

Please refer to FIG3 , which schematically shows the structure of a charging device 3 and a rechargeable battery system 4 charged by the charging device 3 according to the second preferred embodiment of the present invention.

As shown in FIG3 , a charging device 3 according to a second preferred embodiment of the present invention is used to charge a rechargeable battery system 4. The rechargeable battery system 4 includes a battery management system 40 and a first communication unit 42. The first communication unit 42 is electrically connected to the battery management system 40. The battery management system 40 calculates the current state of charge (SOC) percentage of the rechargeable battery system 4.

As shown in FIG3 , the charging device 3 according to the second preferred embodiment of the present invention includes an AC/DC converter 30 , a controller 32 , a DC output unit 34 , and a second communication unit 36 .

The AC/DC converter 30 receives AC power. A controller 32 is electrically connected to the AC/DC converter 30. A DC output unit 34 is electrically connected to the AC/DC converter 30 and the controller 32. The DC output unit 34 is also electrically connected to the rechargeable battery system 4 via a cable 35. The controller 32 controls the DC output unit 34 to turn it on and off. A second communication unit 36 is electrically connected to the controller 32. The second communication unit 36 can communicate with the first communication unit 42 and receives the current battery charge percentage via the first communication unit 42.

The controller 32 determines whether the number of times the first selected battery state percentage has been selected is equal to N based on a plurality of previous charging information, where N is an integer greater than 1. If the controller 32 determines that the number of times the first selected battery state percentage has been selected is equal to N, the controller 32 determines a second selected battery state percentage and controls the AC/DC converter 30 to convert AC power into charging DC power and transmit it to the DC output unit 34. The controller 32 also controls the DC output unit 34 to output charging DC power to charge the rechargeable battery system 4 until the current battery state percentage is equal to the second selected battery state percentage. The second selected battery state percentage is greater than the first selected battery state percentage. In this way, the service life of the rechargeable battery system 4 can be increased.

In one example, the first selected battery state percentage is 80%, and the second selected battery state percentage is 100%.

Furthermore, if the controller 32 determines that the number of times the first selected battery state of charge percentage has been selected is less than N, the controller 32 controls the AC/DC converter 30 to convert AC power into charging DC power and transmit it to the DC output unit 34. The controller 32 also controls the DC output unit 34 to output the charging DC power to charge the rechargeable battery system 4 until the current battery state of charge percentage equals the first selected battery state of charge percentage.

Furthermore, the battery management system 40 detects the cell voltage differential of the rechargeable battery system 4. The second communication unit 36 is configured to receive the cell voltage differential via the first communication unit 42. The controller 32 determines whether the cell voltage differential is equal to or greater than a first threshold. In one embodiment, the first threshold is 80 mV. If the controller 32 determines that the cell voltage differential is equal to or greater than the first threshold, the controller 32 determines a second selected battery state-of-charge percentage and controls the AC/DC converter 30 to convert AC power into charging DC power and transmit it to the DC output unit 34 to charge the rechargeable battery system 4 until the cell voltage differential is less than the second threshold and the current battery state-of-charge percentage is equal to the second selected battery state-of-charge percentage. In one embodiment, the second threshold is equal to 15 mV. Please refer to FIG. 4 , which shows a charging curve diagram of an example of charging the rechargeable battery system 4 using the charging device 3 according to the second preferred embodiment of the present invention. According to the charging curve shown in Figure 4, when the controller 32 determines that the cell voltage differential is greater than 80mV, the controller 32 controls the AC/DC converter 30 to reduce the charging current and cooperates with the internal balancing mechanism of the rechargeable battery system 4 to gradually reduce the cell voltage differential during low-current charging. When the cell voltage differential is less than 15mV, the controller 32 controls the AC/DC converter 30 to resume normal current charging and controls the charging of the rechargeable battery system 4 until the current battery state of charge percentage equals a first selected battery state of charge percentage (for example, the first selected SOC percentage is 100%). In one embodiment, the second threshold value is less than the first threshold value.

Furthermore, the charging device 3 according to the second preferred embodiment of the present invention further includes a detection unit 38. The detection unit 38 is electrically connected to the controller 32 and electrically coupled to the cable 35. The detection unit 38 is used to detect the charging voltage and charging current. The controller 32 controls the DC output unit 34 to adjust the output voltage and current of the charging DC power based on the charging voltage and charging current.

Please refer to FIG5 , which schematically shows the structure of a charging device 5 and a rechargeable battery system 6 charged by the charging device 5 according to the third preferred embodiment of the present invention.

As shown in FIG5 , the charging device 5 according to the third preferred embodiment of the present invention is used to charge the rechargeable battery system 6.

As shown in FIG5 , the charging device 5 according to the third preferred embodiment of the present invention includes an AC/DC converter 50 , a controller 52 , a DC output unit 54 , a detection unit 56 , and a selection unit 58 .

The AC/DC converter 50 is used to receive AC power. The controller 52 is electrically connected to the AC/DC converter 50. The controller 52 stores therein a relationship between a plurality of predetermined charging voltages, a plurality of predetermined charging currents, and a plurality of predetermined battery state of charge percentages.

The DC output unit 54 is electrically connected to the AC/DC converter 50 and the controller 52. The DC output unit 54 is also electrically connected to the rechargeable battery system 6 via a cable 55. The controller 52 controls the DC output unit 54 to turn it on and off. The detection unit 56 is electrically connected to the controller 52 and electrically coupled to the cable 55. The detection unit 56 is used to detect the charging voltage and charging current. The selection unit 58 is electrically connected to the controller 52. The selection unit 58 is operated by the user to input commands. In response to the command, the controller 52 determines a selected battery state-of-charge percentage and determines the current battery state-of-charge percentage from a plurality of predetermined battery state-of-charge percentages based on the charging voltage, charging current, and a relationship. The controller 52 controls the AC/DC converter 50 to convert AC power into charging DC power and transmit it to the DC output unit 54. The controller 52 also controls the DC output unit 54 to output the charging DC power to charge the rechargeable battery system 6 until the current battery state-of-charge percentage equals the selected battery state-of-charge percentage. This increases the service life of the rechargeable battery system 6.

In one embodiment, the relationship is stored in the controller 52 in the form of a lookup table. In another embodiment, the relationship is stored in the controller 52 in the form of an equation.

From the above detailed description of the present invention, it is clear that the charging device according to the present invention can automatically adjust the selected battery state of charge percentage to charge the rechargeable battery system. Thus, by using the charging device according to the present invention to charge the rechargeable battery system, the service life of the rechargeable battery system can be increased.

The above detailed description of the preferred embodiments is intended to more clearly illustrate the features and spirit of the present invention. It is not intended to limit the scope of the present invention to the preferred embodiments disclosed above. Rather, it is intended to encompass various modifications and equivalent arrangements within the scope of the patent application for the present invention. Therefore, the scope of the patent application for the present invention should be interpreted broadly based on the above description to encompass all possible modifications and equivalent arrangements.

1: Charging device 10: AC/DC converter 12: Controller 14: DC output unit 15: Cable 16: Second communication unit 18: Detection unit 2: Rechargeable battery system 20: Battery management system 22: First communication unit 3: Charging device 30: AC/DC converter 32: Controller 34: DC output unit 35: Cable 36: Second communication unit 38: Detection unit 4: Rechargeable battery system 40: Battery management system 42: First communication unit 5: Charging device 50: AC/DC converter 52: Controller 54: DC output unit 55: Cable 56: Detection Unit 58: Selection Unit 6: Rechargeable Battery System

Figure 1 is a charging curve diagram of a prior art rechargeable battery system. Figure 2 is a schematic diagram of the architecture of a charging device according to a first preferred embodiment of the present invention and a rechargeable battery system it charges. Figure 3 is a schematic diagram of the architecture of a charging device according to a second preferred embodiment of the present invention and a rechargeable battery system it charges. Figure 4 is a charging curve diagram of an example of a rechargeable battery system being charged by the charging device according to the second preferred embodiment of the present invention. Figure 5 is a schematic diagram of the architecture of a charging device according to a third preferred embodiment of the present invention and a rechargeable battery system it charges.

1: Charging device

10: AC/DC converter

12: Controller

14: DC output unit

15: Cable

16: Second communication unit

18: Detection Unit

2: Rechargeable battery system

20: Battery Management System

22: First Communication Unit

Claims (7)

A charging device for charging a rechargeable battery system, the rechargeable battery system comprising a battery management system and a first communication unit, the first communication unit being electrically connected to the battery management system, the battery management system calculating a current battery state of charge percentage of the rechargeable battery system, the charging device comprising: an AC/DC converter for receiving AC power; a controller for The first communication unit is electrically connected to the AC/DC converter; the second communication unit is electrically connected to the AC/DC converter and the controller, the DC output unit is electrically connected to the rechargeable battery system via a cable, wherein the controller controls the DC output unit to be turned on or off; and the second communication unit is electrically connected to the controller, the second communication unit can communicate with the first communication unit. The controller is configured to communicate with the first communication unit and receive the current battery state percentage via the first communication unit, wherein the controller determines whether a first selected battery state percentage has been selected a number of times equal to N based on a plurality of previous charging information. If the controller determines that the first selected battery state percentage has been selected a number of times equal to N, the controller determines a second selected battery state percentage and controls the AC/DC converter to convert the AC power into a charging DC power and transmit it to the DC output unit, and controls the DC output unit to output the charging DC power to charge the rechargeable battery system until the current battery state percentage is equal to the second selected battery state percentage, where N is an integer greater than 1, and the second selected battery state percentage is greater than the first selected battery state percentage. A charging device as described in claim 1, wherein if the controller determines that the number of times the first selected battery state of charge percentage has been selected is less than N, the controller controls the AC/DC converter to convert the AC power into the charging DC power and transmit it to the DC output unit, and controls the DC output unit to output the charging DC power to charge the rechargeable battery system until the current battery state of charge percentage is equal to the first selected battery state of charge percentage. The charging device as described in claim 1 further includes: a detection unit electrically connected to the controller and electrically coupled to the cable, the detection unit being used to detect a charging voltage and a charging current, wherein the controller controls the DC output unit to adjust an output voltage and an output current of the charging DC power according to the charging voltage and the charging current. A charging device as described in claim 1, wherein the battery management system detects a battery cell pressure difference of the rechargeable battery system, the second communication unit can and is used to receive the battery cell pressure difference via the first communication unit, and the controller determines whether the battery cell pressure difference is equal to or greater than a first threshold value. If the controller determines that the battery cell pressure difference is equal to or greater than the first threshold value, the controller determines the second selected battery state of charge percentage and controls the AC/DC converter to convert the AC power into the charging DC power and transmit it to the DC output unit to charge the rechargeable battery system until the battery cell pressure difference is less than a second threshold value and the current battery state of charge percentage is equal to the second selected battery state of charge percentage. The charging device as described in claim 4, wherein the second threshold value is smaller than the first threshold value. A charging device for charging a rechargeable battery system, the charging device comprising: an AC/DC converter for receiving AC power; a controller electrically connected to the AC/DC converter, the controller storing therein a relationship between a plurality of predetermined charging voltages, a plurality of predetermined charging currents, and a plurality of predetermined battery state of charge percentages; a DC output unit electrically connected to the AC/DC converter and the controller, the DC output unit being electrically connected to the rechargeable battery system via a cable, wherein the controller controls the DC output unit to be turned on or off; a detection unit electrically connected to the controller and electrically coupled to the cable, the detection unit The controller includes a detection unit for detecting a charging voltage and a charging current; and a selection unit electrically connected to the controller, the selection unit being operated by a user to input a command, wherein the controller determines a selected battery state-of-charge percentage in response to the command, and determines a current battery state-of-charge percentage from the plurality of predetermined battery state-of-charge percentages based on the charging voltage, the charging current, and the relationship. The controller controls the AC/DC converter to convert the AC power into a charging DC power and transmits it to the DC output unit, and controls the DC output unit to output the charging DC power to charge the rechargeable battery system until the current battery state-of-charge percentage is equal to the selected battery state-of-charge percentage. The charging device as described in claim 6, wherein the relationship is stored in the controller in the form of a lookup table.