Power supply device and method thereof

Abstract

A power supply device comprises a first battery and a second battery, and further comprises a first switching unit electrically connected between the first battery and a load and used for selecting the first battery to supply power to the load; the second switching unit is electrically connected between the second battery and a load and is used for selecting the second battery to charge the load; the processing unit is electrically connected to the first battery and the second battery and used for detecting the electric quantity of the first battery and the electric quantity of the second battery, and when the electric quantity of the second battery is larger than a first preset value, the first switching unit is controlled to be disconnected, the second switching unit is controlled to be connected, and the second battery can supply power to a load; meanwhile, the electric quantity of the first battery is detected, and when the electric quantity of the first battery is smaller than a second preset value, the second battery is controlled to charge the first battery; and when the electric quantity of the first battery is greater than a third preset value, the second battery is controlled to stop charging the first battery, so that the charging efficiency and the working stability of the equipment are improved.

Description

Technical Field

[0001] The present invention relates to the field of power supply technology, and in particular to a power supply device and a method thereof. Background Art

[0002] AR / VR is a technology that major manufacturers are striving to develop. Whether it is AR glasses or VR headsets, in addition to the platform's software and hardware performance, in order to allow the product's use location to be unrestricted by wires, battery life is also a performance that users are extremely concerned about. However, in order to increase the product's usage time, it is necessary to increase the power that the battery can provide to the product, which also means that the weight on the user's head is heavier, which will cause the user's discomfort to increase. Therefore, how to make the product lightweight when worn by the user and improve the power supply efficiency to achieve a longer battery life has become one of the development goals of various manufacturers. Summary of the invention

[0003] In view of this, it is necessary to provide a power supply device to solve the above problems. An embodiment of the present invention provides a power supply device, a first battery and a second battery, and further includes:

[0004] a first switching unit, electrically connected between the first battery and a load, and configured to select the first battery to supply power to the load;

[0005] A second switching unit, electrically connected between the second battery and the load, for selecting the second battery to charge the load;

[0006] The processing unit is electrically connected to the first battery and the second battery, and is used to detect the power levels of the first battery and the second battery. When the power level of the second battery is greater than a first preset value, the first switching unit is controlled to be disconnected and the second switching unit is turned on, so that the second battery can supply power to the load. The processing unit also detects the power level of the first battery. When the power level of the first battery is less than a second preset value, the second battery is controlled to charge the first battery. When the power level of the first battery is greater than a third preset value, the second battery is controlled to stop charging the first battery.

[0007] Preferably, it also includes a reminder unit, wherein:

[0008] The reminder unit is electrically connected to the processing unit, and is used to send a battery replacement reminder signal when the processing unit detects that the power level of the second battery is less than a fourth preset value;

[0009] The processing unit is further used to detect whether the second battery enters a battery replacement mode. When the second battery enters the battery replacement mode, the processing unit controls the first switching unit to be turned on and the second switching unit to be turned off, thereby enabling the first battery to supply power to the load.

[0010] Preferably, the processing unit is further used to control the first battery to supply power to the load when the power level of the second battery is less than a fifth preset value and the second battery has not entered the battery replacement mode.

[0011] Preferably, the processing unit is further used for:

[0012] When the battery replacement mode ends, detecting the power level of the second battery again;

[0013] When the power level of the second battery is greater than the first preset value, the first switching unit is disconnected, the second switching unit is turned on, and the second battery is restored to supply power to the load;

[0014] When the power level of the second battery is less than the fourth preset value, detecting the power level of the first battery;

[0015] When the power level of the first battery is greater than a sixth preset value, the first switching unit is turned on, the second switching unit is turned off, and the load is powered by the first battery;

[0016] When the power level of the first battery is less than the sixth preset value, the power-off mode is entered.

[0017] Preferably, it also includes:

[0018] An interface unit, electrically connected to the load, for accessing an external power source;

[0019] a first charging unit, electrically connected to the interface unit and the first battery, and configured to charge the first battery;

[0020] The second charging unit is electrically connected to the interface unit and the second battery, and is used to charge the second battery; wherein:

[0021] When the interface unit is connected to an external power supply, the load is powered by the external power supply, and the processing unit is further used for:

[0022] When it is detected that the second battery is charging the first battery, controlling the second battery to stop supplying power to the first battery;

[0023] When it is detected that the power level of the second battery is less than a seventh preset value, enabling the external power source to charge the second battery through the second charging unit;

[0024] When it is detected that the power level of the first battery is less than an eighth preset value, the external power source is enabled to charge the first battery through the first charging unit.

[0025] An embodiment of the present invention further provides a power supply method, which is applied to a power supply device, wherein the power supply device includes a first battery and a second battery, and the power supply method includes:

[0026] detecting the power level of the second battery;

[0027] When the power level of the second battery is greater than a first preset value, controlling the second battery to supply power to a load;

[0028] detecting the power level of the first battery;

[0029] When the power level of the first battery is less than a second preset value, controlling the second battery to charge the first battery;

[0030] When the power level of the first battery is greater than a third preset value, the second battery is controlled to stop charging the first battery.

[0031] Preferably, the method further comprises:

[0032] When it is detected that the power level of the second battery is less than a fourth preset value, a battery replacement reminder signal is issued;

[0033] detecting whether the second battery enters a battery replacement mode;

[0034] When the second battery enters the battery replacement mode, the first battery is controlled to supply power to the load.

[0035] Preferably, the method further comprises:

[0036] When it is detected that the power level of the second battery is less than a fifth preset value and the second battery has not entered the battery replacement mode, the first battery is controlled to supply power to the load.

[0037] Preferably, the method further comprises:

[0038] When the battery replacement mode ends, the power level of the second battery is detected again:

[0039] When the power level of the second battery is greater than the first preset value, restoring the second battery to supply power to the load;

[0040] When the power level of the second battery is less than the fourth preset value, detecting the power level of the first battery;

[0041] When the power level of the first battery is greater than a sixth preset value, supplying power to the load through the first battery;

[0042] When the power level of the first battery is less than the sixth preset value, the power-off mode is entered.

[0043] Preferably, when an external power source is connected, the method further comprises:

[0044] When it is detected that the second battery is charging the first battery, controlling the second battery to stop supplying power to the first battery;

[0045] When it is detected that the power level of the second battery is less than a seventh preset value, enabling the external power source to charge the second battery;

[0046] When it is detected that the power level of the first battery is less than an eighth preset value, the external power source is enabled to charge the first battery.

[0047] Compared with the prior art, the power supply device provided in the embodiment of the present invention is provided with a first battery and a second battery, the first battery is a built-in battery, and the second battery is an external battery. The power level of the second battery is first detected by the processing unit. When the battery power level is greater than a preset value, the first switching unit is controlled to be disconnected and the second switching unit is turned on. The second battery directly supplies power to the load without passing through a charging unit, thereby greatly improving the charging efficiency. At the same time, when the power level of the first battery is less than a second preset value, the second battery is controlled to charge the first battery. When the power level of the first battery is greater than a third preset value, the second battery is controlled to stop charging the first battery to ensure that the first battery has sufficient power. When the second battery fails or is out of power, power can be supplied by the first battery to improve the working stability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a module schematic diagram of an embodiment of a power supply device of the present invention;

[0049] Figure 2 It is a module schematic diagram of another embodiment of the power supply device of the present invention;

[0050] Figure 3 This is an optional flow chart of an embodiment of a power supply method of the present invention;

[0051] Figure 4 This is an optional flow chart of an embodiment of a power supply method of the present invention;

[0052] Figure 5 This is an optional flow chart of an embodiment of a power supply method of the present invention;

[0053] Figure 6 This is an optional flow chart of an implementation method of the power supply method of the present invention.

[0054] Main component symbols

[0055] 1-Power supply device

[0056] 100-first switching unit

[0057] 101-Second switching unit

[0058] 102-Processing Unit

[0059] 103-First Battery

[0060] 104- Second battery

[0061] 105-Load

[0062] 106-Interface Unit

[0063] 107-First charging unit

[0064] 108- Second charging unit

[0065] S300~S308, S400~S404, S500~S508, S600~S604-Steps

[0066] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific implementation methods and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0068] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0069] See also Figure 1 , Figure 1 1 is a schematic diagram of an optional module of an embodiment of a power supply device 1 of the present invention. The power supply device 1 is applied to wearable devices, especially AR / VR devices. In this embodiment, the power supply device 1 may include a first switching unit 100, a second switching unit 101, a processing unit 102, a first battery 103, a second battery 104 and a load 105.

[0070] The first switching unit 100 is electrically connected between the first battery 103 and the load 105, and is used to select the first battery 103 to supply power to the load 105. The second switching unit 101 is electrically connected between the second battery 104 and the load 105, and is used to select the second battery 104 to charge the load 105. The processing unit 102 is electrically connected to the first battery 103, the second battery 104, the first switching unit 101, and the second switching unit 102, and is used to detect the power levels of the first battery 103 and the second battery 104.

[0071] When the power of the second battery 104 is greater than the first preset value, the processing unit 102 controls the first switching unit 100 to be disconnected, the second switching unit 101 to be turned on, and the second battery 104 supplies power to the load 105. The processing unit 102 also detects the power of the first battery 103 at the same time. When the power of the first battery 103 is less than the second preset value, the second battery 104 is controlled to charge the first battery 103. When the power of the first battery 103 is greater than the third preset value, the processing unit 102 controls the second battery 104 to stop charging the first battery 103. The first preset value may be 10% of the power of the second battery 104, the second preset value may be 80% of the power of the first battery 103, and the third preset value may be 95% of the power of the first battery 103. The first preset value, the second preset value and the third preset value can be set according to actual applications. For example, the second preset value is set to 80% of the power of the first battery 103 in order to ensure that the first battery 103 has sufficient power in actual applications. When the power of the second battery 104 is less than the preset value, such as 40% of the power, the first battery 103 is no longer charged and only the load 105 is powered, giving priority to ensuring the power supply of the load 105.

[0072] In this embodiment, when the second battery 104 supplies power to the load 105 and the processing unit 102 detects that the power level of the first battery 103 is less than the second preset value, the second battery 104 is controlled to charge the first battery 103 .

[0073] In this embodiment, the first battery 103 is a built-in battery, and the second battery 104 is an external battery and a replaceable battery. When the second battery 104 is exhausted, a new battery can be replaced. When the second battery 104 is replaced, the power supply device 1 enters a battery replacement mode.

[0074] In this embodiment, the power supply device 1 may further include a reminder unit (not shown), which is electrically connected to the processing unit 102 and is used to issue a battery replacement reminder when the processing unit 102 detects that the power level of the second battery 104 is less than a fourth preset value. The processing unit 102 is also used to detect whether the second battery 104 enters a battery replacement mode, and when the second battery 104 enters the battery replacement mode, the first battery 103 is controlled to supply power to the load 105.

[0075] When it is detected that the power of the second battery 104 is less than the fifth preset value and the second battery 104 does not enter the battery replacement mode, the processing unit 102 further controls the first battery 103 to supply power to the load 105. The fourth preset value may be 15% of the power of the second battery 104, and the fifth preset value may be 6% of the power of the second battery 104. It is understood that the fourth preset value and the fifth preset value may be determined according to actual applications and are not limited here.

[0076] In this embodiment, the power supply device 1 may further include a battery replacement trigger unit (not shown), which is electrically connected to the processing unit 102 and the second battery 104, and is used to detect whether the second battery 104 enters the battery replacement mode, and sends a trigger signal when it is detected that the second battery 104 enters the battery replacement mode. The processing unit 102 controls the first battery 103 to supply power to the load 105 according to the trigger signal. In other embodiments of the present invention, the battery replacement trigger unit may be integrated in the processing unit 102, which is not limited here.

[0077] The processing unit 102 is also used to detect the power of the second battery 104 again when the battery replacement mode ends, that is, to detect the power of the newly replaced second battery 104. When the power of the second battery 104 is greater than the first preset value, the first switching unit 100 is disconnected, the second switching unit 101 is turned on, and the second battery 104 is restored to supply power to the load 105; when the power of the second battery 104 is less than the fourth preset value, the power of the first battery 103 is detected; when the power of the first battery 103 is greater than the sixth preset value, the first switching unit 100 is turned on, the second switching unit 101 is disconnected, and the load 105 is supplied with power through the first battery 103; when the power of the first battery 103 is less than the sixth preset value, the shutdown mode is entered. The sixth preset value can be 10% of the power of the first battery. It can be understood that the sixth preset value can be determined according to actual applications and is not limited here.

[0078] Figure 2 1 is a schematic diagram of a module of another embodiment of the power supply device 1 of the present invention. The power supply device 1 in this embodiment is different from the power supply device 1 in the above embodiment in that it also includes an interface unit 106, a first charging unit 107 and a second charging unit 108. The working principles of the first switching unit 100, the second switching unit 101, the processing unit 102, the first battery 103, the second battery 104 and the load 105 are similar to those in the above embodiment and will not be repeated here.

[0079] In this embodiment, the interface unit 106 is electrically connected to the load 105 for accessing an external power source. The first charging unit 107 is electrically connected to the interface unit 106 and the first battery 103 for charging the first battery 103. The second charging unit 108 is electrically connected to the interface unit 106 and the second battery 104 for charging the second battery 104.

[0080] In this embodiment, when the interface unit 106 is connected to an external power source, the external power source is used to supply power to the load 105. When the processing unit 102 detects that the second battery 104 is charging the first battery 103, the second battery 104 is controlled to stop supplying power to the first battery 103. Furthermore, the processing unit 102 detects the power levels of the first battery 103 and the second battery 104 respectively. When the power level of the second battery 104 is detected to be less than the seventh preset value, the external power source is enabled to charge the second battery 104 through the second charging unit 108; when the power level of the first battery 103 is detected to be less than the eighth preset value, the external power source is enabled to charge the first battery 103 through the first charging unit 107.

[0081] In this embodiment, the power supply device 1 further includes a power conversion unit (not shown), which is electrically connected to the interface unit 106, the first charging unit 107 and the second charging unit 108, and is used to convert the external power supply voltage into a preset voltage value. In other embodiments, the power conversion unit can also be integrated in the interface unit 106, which is not limited here. When the second battery 104 supplies power to the load 105, and the processing unit 102 detects that the power of the second battery 104 is less than the second preset value, the OTG mode of the second charging unit 108 is turned on, and the second battery 104 is controlled to charge the first battery 103. Specifically, before turning on the OTG function of the second charging unit 108, the processing unit 102 controls the first charging unit 107 and the second charging unit 108 to disconnect from the power conversion unit, and then turns on the OTG function of the second charging unit 108, thereby boosting the voltage of the second battery 104 and supplying it to the first charging unit 107 to charge the first battery 103.

[0082] See also Figure 3 , Figure 3 FIG. 1 is an optional flow chart of an embodiment of a power supply method of the present invention. The power supply method is applied to the power supply device of the above embodiment. Figure 3 As shown, the power supply method includes steps S300 to S308, wherein:

[0083] Step S300 , detecting the power level of the second battery 104 .

[0084] Step S302 , when the power level of the second battery 104 is greater than a first preset value, controlling the second battery 104 to supply power to the load 105 .

[0085] Step S304 , detecting the power level of the first battery 103 .

[0086] Step S306 , when the power level of the first battery 103 is less than a second preset value, controlling the second battery 104 to charge the first battery 103 .

[0087] Step S308 , when the power level of the first battery 103 is greater than a third preset value, control the second battery 104 to stop charging the first battery 103 .

[0088] In this embodiment, the first preset value may be 10% of the power of the second battery 104, the second preset value may be 80% of the power of the first battery 103, and the third preset value may be 95% of the power of the first battery 103. The first preset value, the second preset value, and the third preset value may be set according to actual applications. For example, the second preset value is set to 80% of the power of the first battery 103 in order to ensure that the power of the first battery 103 is sufficient in actual applications. When the power of the second battery 104 is less than the preset value, for example, 40% of the power, the first battery 103 is no longer charged, and only the load 105 is powered, so that the power supply of the load 105 is prioritized.

[0089] See also Figure 4 , Figure 4 FIG. 1 is an optional flow chart of an embodiment of a power supply method of the present invention. Figure 4 As shown, the power supply method may further include steps S400 to S404, wherein:

[0090] In step S400, when it is detected that the power level of the second battery 104 is less than a fourth preset value, a battery replacement reminder signal is issued.

[0091] Step S402, detecting whether the second battery 104 enters the battery replacement mode, if so, executing step S404, if not, returning to step S400, continuing to send the reminder signal.

[0092] Step S404 , controlling the first battery 103 to supply power to the load 105 .

[0093] Specifically, when the second battery 104 has not entered the battery replacement mode, and it is detected that the power of the second battery 104 is less than the fifth preset value, the first battery 103 is controlled to supply power to the load 105. The fourth preset value may be 15% of the power of the second battery, and the fifth preset value may be 6% of the power of the second battery 104. It is understood that the fourth preset value and the fifth preset value may be determined according to actual applications and are not limited here.

[0094] See also Figure 5 , Figure 5 FIG. 1 is an optional flow chart of an embodiment of a power supply method of the present invention. Figure 5 As shown, the power supply method may further include steps S500 to S508, wherein:

[0095] Step S500, when the battery replacement mode ends, detecting the power level of the second battery 104 again;

[0096] Step S502, when the power level of the second battery 104 is greater than the first preset value, the second battery 104 is restored to supply power to the load 105;

[0097] Step S504, when the power level of the second battery 104 is less than the fourth preset value, a battery replacement reminder signal is issued and the power level of the first battery 103 is detected;

[0098] Step S506, when the power level of the first battery 103 is greater than a sixth preset value, power is supplied to the load 105 through the first battery 103;

[0099] Step S508: when the power level of the first battery 103 is less than the sixth preset value, entering the shutdown mode.

[0100] In this embodiment, the sixth preset value may be 10% of the power of the first battery 103. It is understandable that the sixth preset value may be determined according to actual applications and is not limited here.

[0101] See also Figure 6 , Figure 6 FIG. 1 is an optional flow chart of an embodiment of a power supply method of the present invention. Figure 6 As shown, the power supply method may further include steps S600 to S604, wherein:

[0102] Step S600 , when it is detected that the second battery 104 is charging the first battery 103 , the second battery 104 is controlled to stop supplying power to the first battery 103 .

[0103] Step S602, when it is detected that the power level of the second battery 104 is less than a seventh preset value, enabling the external power source to charge the second battery 104;

[0104] Step S604 , when it is detected that the power level of the first battery 103 is less than an eighth preset value, the external power source is enabled to charge the first battery 103 .

[0105] Compared with the prior art, the power supply device provided in the embodiment of the present invention is provided with a first battery and a second battery, the first battery is a built-in battery, and the second battery is an external battery. The power level of the second battery is first detected by the processing unit. When the battery power level is greater than a preset value, the first switching unit is controlled to be disconnected and the second switching unit is turned on. The second battery directly supplies power to the load without passing through a charging unit, thereby greatly improving the charging efficiency. At the same time, when the power level of the first battery is less than a second preset value, the second battery is controlled to charge the first battery. When the power level of the first battery is greater than a third preset value, the second battery is controlled to stop charging the first battery to ensure that the first battery has sufficient power. When the second battery fails or is out of power, power can be supplied by the first battery to improve the working stability of the equipment.

[0106] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, appropriate changes and modifications to the above embodiments are within the scope of protection claimed by the present invention.

Claims

1. A power supply device, comprising a first battery and a second battery, characterized in that: Also includes: a first switching unit, electrically connected between the first battery and a load, and configured to select the first battery to supply power to the load; A second switching unit, electrically connected between the second battery and the load, for selecting the second battery to charge the load; The processing unit is electrically connected to the first battery and the second battery, and is used to detect the power level of the second battery. When the power level of the second battery is greater than a first preset value, the first switching unit is controlled to be disconnected and the second switching unit is turned on, so that the second battery can supply power to the load; the power level of the first battery is detected at the same time. When the power level of the first battery is less than a second preset value, the second battery is controlled to charge the first battery; when the power level of the first battery is greater than a third preset value, the second battery is controlled to stop charging the first battery.

2. The power supply device according to claim 1, characterized in that: Also includes a reminder unit, wherein the reminder unit is electrically connected to the processing unit, and is used to send a battery replacement reminder signal when the processing unit detects that the power level of the second battery is less than a fourth preset value; The processing unit is further used to detect whether the second battery enters a battery replacement mode. When the second battery enters the battery replacement mode, the processing unit controls the first switching unit to be turned on and the second switching unit to be turned off, thereby enabling the first battery to supply power to the load.

3. The power supply device according to claim 2, characterized in that: The processing unit is further configured to control the first battery to supply power to the load when the power level of the second battery is less than a fifth preset value and the second battery has not entered the battery replacement mode.

4. The power supply device according to claim 2, characterized in that: The processing unit is also used for: When the battery replacement mode ends, detecting the power level of the second battery again; When the power level of the second battery is greater than the first preset value, the first switching unit is disconnected, the second switching unit is turned on, and the second battery is restored to supply power to the load; When the power level of the second battery is less than the fourth preset value, detecting the power level of the first battery; When the power level of the first battery is greater than a sixth preset value, the first switching unit is turned on, the second switching unit is turned off, and the load is powered by the first battery; When the power level of the first battery is less than the sixth preset value, the power-off mode is entered.

5. The power supply device according to claim 1, characterized in that: Also includes: An interface unit, electrically connected to the load, for accessing an external power source; a first charging unit, electrically connected to the interface unit and the first battery, and configured to charge the first battery; The second charging unit is electrically connected to the interface unit and the second battery, and is used to charge the second battery; wherein: When the interface unit is connected to the external power supply, the load is powered by the external power supply, and the processing unit is further used for: When it is detected that the second battery is charging the first battery, controlling the second battery to stop supplying power to the first battery; When it is detected that the power level of the second battery is less than a seventh preset value, enabling the external power source to charge the second battery through the second charging unit; When it is detected that the power level of the first battery is less than an eighth preset value, the external power source is enabled to charge the first battery through the first charging unit.

6. A power supply method, applied to a power supply device, the power supply device comprising a first battery and a second battery, characterized in that: The power supply method comprises: detecting the power level of the second battery; When the power level of the second battery is greater than a first preset value, controlling the second battery to supply power to a load; detecting the power level of the first battery; When the power level of the first battery is less than a second preset value, controlling the second battery to charge the first battery; When the power level of the first battery is greater than a third preset value, the second battery is controlled to stop charging the first battery.

7. The power supply method according to claim 6, characterized in that: The method further comprises: When it is detected that the power level of the second battery is less than a fourth preset value, a battery replacement reminder signal is issued; detecting whether the second battery enters a battery replacement mode; When the second battery enters the battery replacement mode, the first battery is controlled to supply power to the load.

8. The power supply method according to claim 7, characterized in that: The method further comprises: When it is detected that the power level of the second battery is less than a fifth preset value and the second battery has not entered the battery replacement mode, the first battery is controlled to supply power to the load.

9. The power supply method according to claim 7, characterized in that: The method further comprises: When the battery replacement mode ends, the power level of the second battery is detected again: When the power level of the second battery is greater than the first preset value, restoring the second battery to supply power to the load; When the power level of the second battery is less than the fourth preset value, detecting the power level of the first battery; When the power level of the first battery is greater than a sixth preset value, supplying power to the load through the first battery; When the power level of the first battery is less than the sixth preset value, the power-off mode is entered.

10. The power supply method according to claim 6, characterized in that: When an external power source is connected, the method further comprises: When it is detected that the second battery is charging the first battery, controlling the second battery to stop supplying power to the first battery; When it is detected that the power level of the second battery is less than a seventh preset value, enabling the external power source to charge the second battery; When it is detected that the power level of the first battery is less than an eighth preset value, the external power source is enabled to charge the first battery.

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