Lithium battery anti-floating charging method, power supply system and equipment, protection system and medium

Abstract

The invention relates to the technical field of lithium batteries, in particular to a lithium battery floating charge prevention method, a power supply system and equipment, a protection system and a medium. The method is applied to a lithium battery power supply system and comprises a lithium battery, a lithium battery protection circuit and a system main circuit, the lithium battery protection circuit comprises a lithium battery protection chip, and a charging switch tube and a discharging switch tube which are connected with the lithium battery protection chip; the system main circuit comprises a main control chip, the main control chip is connected with a charging switch tube, and the method comprises the following steps that battery information of a lithium battery is obtained through a sampling circuit, and the battery information comprises at least one of battery voltage, charging current and discharging current; judging whether the lithium battery is in a charging and discharging state or not based on the management information of the power management module; if yes, whether the battery voltage exceeds a voltage threshold value and whether the charging current is lower than a current threshold value are judged; and if yes, controlling the lithium battery protection circuit to be in a preset floating charge protection state, and closing the charging switch tube. The use safety of the lithium battery can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, in particular to a lithium battery anti-floating charge method, a power supply system and equipment, a protection system and a medium. Background Art

[0002] In a lithium battery power supply system, a lithium battery protection circuit is usually provided to protect the power safety of the lithium battery. A lithium battery protection chip is provided in the lithium battery protection circuit. The lithium battery protection chip is used to turn on or off the charge / discharge path of the lithium battery according to the current charge / discharge situation.

[0003] When charging a lithium battery, when the battery voltage reaches the set voltage value, the charging mode will be converted to a constant voltage. At this time, the charging current will gradually decrease as the battery power increases. When the current decreases to a set threshold, the power management module will consider that the stop charging judgment condition is met and the battery is fully charged, and thus stop charging.

[0004] When the lithium battery power supply system is in the state of charging and discharging at the same time, because other functional modules or output terminals in the system have load current, a larger input current is required. This larger input current will cause the power management module to think that the current charging current is too large and does not meet the conditions for stopping charging and judging fullness, thus maintaining the constant voltage charging state. In this state, the battery will be in a floating charge state for a long time, which may have a negative impact on the life and health of the battery, for example, causing the battery to overheat, swell, or even be damaged. Summary of the invention

[0005] The technical problem to be solved by the embodiments of the present invention is to provide a lithium battery anti-floating charge method, a power supply system and equipment, a protection system and a medium to solve the problem in the prior art that the battery may be in floating charge for a long time.

[0006] The present invention discloses a lithium battery floating charge prevention method, which is applied to a lithium battery power supply system. The lithium battery power supply system comprises a lithium battery, a lithium battery protection circuit and a system main circuit;

[0007] The lithium battery protection circuit comprises a lithium battery protection chip and a charging switch tube and a discharging switch tube connected to the lithium battery protection chip, wherein the charging switch tube is connected to the lithium battery, and the discharging switch tube is connected to the lithium battery through the charging switch tube;

[0008] The main circuit of the system includes a main control chip, a sampling circuit connected to the main control chip, and a power management module, wherein the power management module is used to manage the input and output currents of the lithium battery power supply system, the main control chip is connected to the charging switch tube, and the sampling circuit is connected to the discharging switch tube;

[0009] The lithium battery floating charge prevention method comprises the following steps:

[0010] Acquiring battery information of the lithium battery through the sampling circuit, wherein the battery information includes at least one of battery voltage, charging current, and discharging current;

[0011] Acquire management information of the power management module, and determine whether the lithium battery is in a state of charging and discharging based on the management information;

[0012] If yes, determining whether the battery voltage exceeds a voltage threshold and whether the charging current is lower than a current threshold;

[0013] If so, the lithium battery protection circuit is controlled to be in a preset floating charge protection state, and the charging switch tube is turned off.

[0014] Optionally, before the step of determining whether both the battery voltage and the charging current do not meet a preset safety condition, the step includes:

[0015] It is determined whether the discharge current exceeds a preset release threshold value. If so, the lithium battery protection circuit is controlled to exit a preset floating charge protection state and the charging switch tube is turned on.

[0016] Optionally, before the step of controlling the lithium battery protection circuit to be in a preset floating charge protection state, the step includes:

[0017] It is determined whether the discharge current exceeds a preset release threshold value. If not, the lithium battery protection circuit is controlled to be in a preset floating charge protection state, and the charging switch tube is turned off.

[0018] Optionally, before the step of determining whether the discharge current exceeds a preset release threshold, the step includes:

[0019] Determine whether the lithium battery protection circuit is in the preset floating charge protection state, and if so, execute the step of determining whether the discharge current exceeds a preset release threshold, and subsequent steps;

[0020] If not, the step of determining whether both the battery voltage and the charging current do not meet the preset safety condition and subsequent steps are performed.

[0021] Optionally, a protection flag is preset, and after the step of controlling the lithium battery protection circuit to be in a preset floating charge protection state, the method further comprises:

[0022] Setting the protection flag;

[0023] After the step of controlling the lithium battery protection circuit to exit the preset floating charge protection state, the method further comprises:

[0024] Setting the protection flag to zero;

[0025] The step of determining whether the lithium battery protection circuit is in the preset floating charge protection state comprises:

[0026] It is determined whether the protection flag is in a set state.

[0027] Optionally, after the step of determining whether the lithium battery is in a state of charging and discharging based on the management information, the method further comprises:

[0028] If the lithium battery is in a single discharge state or a single charge state, determining whether the lithium battery protection circuit is in the preset floating charge protection state;

[0029] If so, the lithium battery protection circuit is controlled to exit the preset floating charge protection state and the charging switch tube is turned on.

[0030] The present invention also discloses a lithium battery power supply system, which is used to implement the lithium battery anti-floating charge method as described above;

[0031] The lithium battery power supply system comprises a lithium battery, a lithium battery protection circuit and a system main circuit;

[0032] The lithium battery protection circuit comprises a lithium battery protection chip and a charging switch tube and a discharging switch tube connected to the lithium battery protection chip, wherein the discharging switch tube is connected to the lithium battery, and the charging switch tube is connected to the lithium battery through the discharging switch tube;

[0033] The system main circuit includes a main control chip and a sampling circuit connected to the main control chip, the main control chip is connected to the charging switch tube, and the sampling circuit is connected to the charging switch tube.

[0034] The present invention also discloses a lithium battery protection system, which is applied to the lithium battery power supply system as described above, and comprises:

[0035] A sampling module, used to obtain battery information of the lithium battery through a sampling circuit, wherein the battery information includes at least one of a battery voltage, a charging current, and a discharging current;

[0036] A status module, used to obtain management information of the power management module, and determine whether the lithium battery is in a state of charging and discharging based on the management information;

[0037] A safety module, used to determine whether both the battery voltage and the charging current do not meet a preset safety condition when the lithium battery is in a state of charging and discharging;

[0038] The control module is used to control the lithium battery protection circuit to be in a preset floating charge protection state and turn off the charging switch tube when the battery voltage is higher than a preset voltage threshold and the charging current is lower than a current threshold.

[0039] The present invention also discloses a power supply device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above method.

[0040] The present invention also discloses a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the steps of the method described above.

[0041] Compared with the prior art, the lithium battery anti-floating charge method provided by the embodiment of the present invention has the beneficial effect that: the main control chip is connected to the charging switch tube, so as to control the shutdown / conduction of the charging switch tube, so that when the lithium battery is in a state of charging and discharging, the power management module cannot stop charging due to the presence of the load, which causes the charging current to not meet the stop charging judgment condition when the battery is already full, and the main control chip turns off the charging switch tube to avoid the floating charge phenomenon in time, effectively ensuring the safe use of the lithium battery and extending its service life. There is no need to add an additional high-current switch MOS tube to the current main circuit, which effectively reduces the control cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, in which:

[0043] Figure 1 It is a flow chart of a first embodiment of a lithium battery floating charge prevention method provided by the present invention;

[0044] Figure 2 is a structural schematic diagram of a first embodiment of a lithium battery power supply system provided by the present invention;

[0045] Figure 3 It is a flow chart of a second embodiment of the method for preventing floating charge of a lithium battery provided by the present invention;

[0046] Figure 4 It is a schematic flow chart of a third embodiment of the lithium battery floating charge prevention method provided by the present invention;

[0047] Figure 5 1 is a flow chart of a fourth embodiment of a lithium battery floating charge prevention method provided by the present invention;

[0048] Figure 6 1 is a flow chart of a fifth embodiment of a lithium battery floating charge prevention method provided by the present invention;

[0049] Figure 7 It is a structural schematic diagram of an embodiment of a lithium battery protection system provided by the present invention.

[0050] The reference numerals in the figures are:

[0051] 10. Lithium battery power supply system; 11. Lithium battery; 12. Lithium battery protection circuit; 121. Lithium battery protection chip; 122. Charging switch tube; 123. Discharging switch tube; 13. System main circuit; 131. Power input port; 132. Power output port; 133. Other functional modules; 134. First power management module; 135. Second power management module; 136. Sampling circuit; 20. Lithium battery protection system; 21. Sampling module; 22. Status module; 23. Safety module; 24. Control module. DETAILED DESCRIPTION

[0052] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. Now, in conjunction with the accompanying drawings, a preferred embodiment of the present invention is described in detail.

[0053] Please refer to Figure 1 and Figure 2 , Figure 1 is a flow chart of a first embodiment of a lithium battery anti-floating charge method provided by the present invention, Figure 2 Schematic diagram of the structure of the first embodiment of the lithium battery power supply system provided by the present invention. Figure 2 As shown in FIG. 1 , the lithium battery power supply system 10 includes a lithium battery 11, a lithium battery protection circuit 12 and a system main circuit 13. The lithium battery 11 can be a single-cell lithium battery or a multi-cell lithium battery, and can be configured according to actual use requirements.

[0054] The system main circuit 13 includes a power management module, which is used to control the input and output currents of the lithium battery power supply system 10. Specifically, a first power management module 134 for managing input current and a second power management module 135 for managing output current can be provided respectively.

[0055] The system main circuit 13 includes a power input port 131 for receiving external power input and a power output port 132 for outputting power to the outside, as well as other functional modules 133 for realizing other functions. The power input port 131 is connected to a first power management module 134, which is used to output the power received by the power input port 131 to the lithium battery 11, the power output port 132 and the other functional modules 133 respectively, so that the power provided by the outside can realize at least one of the three operations of maintaining the operation of the system main circuit 13, storing electricity in the lithium battery 11, and providing power to the outside. The power output port 132 is connected to a second power management module 135, which is used to receive the external power provided by the power input port 131 and the battery power provided by the lithium battery 11, and provide these two power sources to the power output port 132 for output.

[0056] The lithium battery protection circuit 12 includes a lithium battery protection chip 121, a charging switch tube 122 and a discharging switch tube 123. The charging switch tube 122 and the discharging switch tube 123 are both MOS tubes, specifically N-type MOS tubes. The D pole of the charging switch tube 122 is connected to the D pole of the discharging switch tube 123, and the G pole of the charging switch tube 122 and the G pole of the discharging switch tube 123 are connected to the lithium battery protection chip 121, so that the lithium battery protection chip 121 can control the on and off of the charging switch tube 122 and the discharging switch tube 123. It can be understood that when the charging switch tube 122 is in the on state, the lithium battery 11 can receive the power provided by the first power management module 134 for charging, and when the charging switch tube 122 is in the off state, the power provided by the first power management module 134 will not be transmitted to the lithium battery 11. When the discharge switch tube 123 is in the on state, the lithium battery 11 can provide power to the second power management module 135 and other functional modules 133. When the discharge switch tube 123 is in the off state, the power inside the lithium battery 11 cannot be output.

[0057] In this embodiment, the system main circuit 13 includes a main control chip 137, and the main control chip 137 is connected to each circuit / module in the system main circuit. The main control chip 137 is also connected to the charging switch tube 122, so that the main control chip 137 can control the shutdown and conduction of the charging switch tube 122, that is, it can control whether the lithium battery 11 can be charged. In other implementation scenarios, in order to ensure the safe operation of the main control chip 137, an isolation tube is set between the main control chip 137 and the charging switch tube 122, and the isolation tube is also a MOS tube. The S pole of the isolation tube is connected to the S pole of the charging switch tube 122, the G pole of the isolation tube is connected to the main control chip 137, and the D pole is connected to the G pole of the charging switch tube 122. When it is necessary to control the charging switch 122 to be turned off, the active chip 137 drives the isolation tube to be turned on, so that the Vgs of the charging switch tube 122 is less than the conduction threshold, so that the charging switch tube 122 is turned off.

[0058] The system main circuit 13 also includes a sampling circuit 136, which is connected to the charging switch tube 122. Since the charging switch tube 122 is connected to the discharging switch tube 123, and the discharging switch tube 123 is connected to the lithium battery 11, the sampling circuit 136 can obtain the actual information of the current input / output of the lithium battery 11 through the lithium battery protection circuit 12. The main control chip 137 can determine whether the current charging switch tube 122 needs to be turned off / on based on the actual information collected by the sampling circuit 136. The specific judgment process of the main control chip 137 is as follows:

[0059] The lithium battery anti-floating charge method provided by the present invention comprises the following steps:

[0060] S101: Obtaining battery information of a lithium battery through a sampling circuit, where the battery information includes at least one of a battery voltage, a charging current, and a discharging current.

[0061] In a specific implementation scenario, the charging / discharging of the lithium battery needs to pass through the lithium battery protection circuit. Therefore, the sampling circuit connected to the input / output port of the lithium battery protection circuit can obtain the battery information of the lithium battery, and the battery information includes at least one of the battery voltage, charging current, and discharging current.

[0062] S102: Obtain management information through the power management module, and determine whether the lithium battery is in a state of charging and discharging based on the management information; if so, execute step S103.

[0063] In a specific implementation scenario, the power management module can usually monitor the voltage, current, temperature and other parameters of the lithium battery, and record these parameters as management information. By obtaining the management information, the current and / or voltage information of charging / discharging can be obtained. When the lithium battery is in a state of simultaneous charging and discharging, the power management module can detect the existence of charging current and discharging current at the same time, so it can be determined whether the lithium battery is in a state of simultaneous charging and discharging based on the management information. Figure 2 In the application scenario shown, the management information of the first power management module can be obtained because the first power management module manages the charging function of the lithium battery-powered device.

[0064] S103: Determine whether the battery voltage exceeds a voltage threshold and whether the charging current is lower than a current threshold; if so, execute step S104.

[0065] In a specific implementation scenario, when the lithium battery is in a state of charging and discharging at the same time, floating charge may occur. If the lithium battery is in a single discharge state and there is no power input, there will naturally be no floating charge problem. If the lithium battery is in a single charging state, the input current will not be affected by the load and will gradually decrease under a constant voltage state. The power management module can accurately determine whether it is fully charged based on the input current, so that it can stop charging when the stop-charging judgment condition is met, and floating charge will not occur.

[0066] Therefore, when the lithium battery is in a state of charging and discharging, it is determined whether floating charge may occur based on the battery voltage and charging current. The voltage threshold can be close to and slightly lower than the upper voltage limit when the battery is fully charged. When the battery voltage reaches the voltage threshold, the lithium battery is theoretically fully charged. The current threshold can be close to and slightly higher than the lower current limit when the battery is fully charged. When the charging current drops to the current threshold, the lithium battery is theoretically close to or has been fully charged.

[0067] Therefore, when the battery voltage of the lithium battery has exceeded the voltage threshold and the charging current is lower than the current threshold, the lithium battery can be considered to be fully charged. However, if a small amount of current is still provided to the lithium battery to maintain the battery voltage of the lithium battery at a high level when it is fully charged, floating charge will occur. Long-term overcharging will cause gas to be generated inside the battery, increase the battery temperature, reduce the battery life, and even damage the battery. Continuous floating charge will cause excessive heat to be generated inside the battery, which may cause the battery to overheat, thereby affecting the performance and safety of the battery. In addition, long-term floating charge may also cause instability of the chemical reaction inside the battery, affecting the performance of the battery and shortening the battery life.

[0068] S104: Control the lithium battery protection circuit to be in a preset floating charge protection state and turn off the charging switch tube.

[0069] In a specific implementation scenario, since the battery is in a state of charging and discharging at the same time, there is a certain discharge current, so the charging current of the battery cannot reach the threshold corresponding to the condition for stopping charging and judging that the battery is full. The power management module detects that the current charging current is large and will not determine that the current lithium battery is already in a full state and stop charging. Therefore, the main control chip is required to control the lithium battery protection circuit to be in a preset floating charge protection state and turn off the charging switch tube to stop the input charging current and prevent floating charge.

[0070] The charging switch tube is a MOS tube, which has a parasitic diode. This diode is generated due to the internal structure of the MOS tube. When the charging switch MOS tube is in the off state, this parasitic diode still exists and will work. When the lithium battery protection circuit is controlled to enter the charging protection state, the charging switch MOS tube is in the off state, but the parasitic diode still exists. In this case, if an external discharge load is connected to the battery, even if the charging switch MOS tube is turned off, the discharge current of the lithium battery can flow unidirectionally through this parasitic diode. In this way, the discharge function of the lithium battery is almost unaffected by the closure of the charging switch MOS tube, and the current can continue to flow, thereby realizing the discharge function.

[0071] However, due to the unidirectionality of the parasitic diode, current is only allowed to flow in one direction. Even if the outside world continues to input current through the main control circuit, these currents will not be transmitted to the lithium battery. Therefore, the lithium battery will no longer be charged, avoiding the occurrence of floating charge.

[0072] In other implementation scenarios, if the charging current is greater than the charging threshold, or the battery voltage is lower than the voltage threshold, it means that the remaining power in the current lithium battery is small. At this time, floating charge will not occur when charging the lithium battery, so the main control chip does not turn off the charging switch tube.

[0073] The signals output by the main control chip except for turning off the charging switch tube are invalid signals. Such invalid signals will not affect the operation of the charging switch tube, and will not interfere with the normal operation of the lithium battery protection circuit.

[0074] It can be seen from the above description that in this embodiment, the main control chip is connected to the charging switch tube, so that the charging switch tube can be controlled to be turned off / on, so that when the lithium battery is in a state of charging and discharging, the power management module cannot stop charging due to the presence of the load, which causes the charging current to not meet the stop charging judgment condition when the battery is fully charged. The main control chip turns off the charging switch tube to avoid the floating charge phenomenon in time, effectively ensuring the safe use of the lithium battery and extending its service life. There is no need to add an additional high-current switch MOS tube to the current main circuit, which effectively reduces the control cost.

[0075] See also Figure 3 , Figure 3 1 is a flow chart of a second embodiment of the method for preventing floating charge of a lithium battery provided by the present invention. The method for preventing floating charge of a lithium battery provided by the present invention comprises the following steps:

[0076] S201: Obtaining battery information of a lithium battery through a sampling circuit, where the battery information includes at least one of a battery voltage, a charging current, and a discharging current.

[0077] S202: Determine whether the lithium battery is in a state of charging and discharging based on the management information; if so, execute step S203.

[0078] In a specific implementation scenario, steps S201-S202 are substantially consistent with steps S101-S102 in the first embodiment of the lithium battery anti-floating charge method provided by the present invention, and will not be described in detail here.

[0079] S203: Determine whether the discharge current exceeds a preset release threshold, if so, execute step S204.

[0080] In a specific implementation scenario, when a lithium battery is in a state of charging and discharging, if the discharge current is large, the power consumption in the lithium battery is large, the battery voltage will be correspondingly lowered, the remaining power in the lithium battery is small, and the probability of floating charge is low, so the lithium battery protection circuit can be uncontrolled. Therefore, in this embodiment, a release threshold is preset, and when the discharge current exceeds the preset release threshold, it proves that the discharge current is large at this time, and the probability of floating charge is low.

[0081] However, since the internal parasitic diode of the charging switch tube has a certain forward conduction voltage drop when the charging switch tube is in the off state, this voltage drop will cause a certain amount of energy loss when current flows through it. The greater the discharge current, the greater the loss. Therefore, when the discharge current exceeds the preset release threshold, the charging switch tube needs to be turned on to avoid power loss.

[0082] S204: Control the lithium battery protection circuit to exit the preset floating charge protection state and turn on the charging switch tube.

[0083] In a specific implementation scenario, the discharge current exceeds the preset release threshold, so the main control chip does not need to control the charging switch tube to be in the off state. In order to avoid power loss, the main control chip can control the charging switch tube to be in the on state.

[0084] From the above description, it can be seen that in this embodiment, whether the discharge current exceeds the preset release threshold, it indicates that the current discharge current is large, so the probability of floating charge is low, and when the discharge current is large, the power consumption caused by the parasitic diode is also large, and the main control chip turns on the charging switch tube, thereby reducing the impedance on the discharge path, thereby reducing the power consumption, effectively improving resource utilization and avoiding power waste.

[0085] See also Figure 4 , Figure 4 1 is a flow chart of a third embodiment of a method for preventing floating charge of a lithium battery provided by the present invention. The method for preventing floating charge of a lithium battery provided by the present invention comprises the following steps:

[0086] S301: Obtaining battery information of a lithium battery through a sampling circuit, where the battery information includes at least one of a battery voltage, a charging current, and a discharging current.

[0087] S302: Determine whether the lithium battery is in a state of simultaneous charging and discharging based on the management information. If yes, execute step S303.

[0088] S303: Determine whether the battery voltage exceeds a voltage threshold and whether the charging current is lower than a current threshold; if so, execute step S304.

[0089] In a specific implementation scenario, steps S301-S303 are substantially the same as steps S101-S103 in the first embodiment of the lithium battery anti-floating charge method provided by the present invention, and will not be described in detail here.

[0090] S304: Determine whether the discharge current exceeds a preset release threshold, if not, execute step S305, if yes, execute step S306.

[0091] In a specific implementation scenario, when the battery voltage exceeds the voltage threshold and the charging current is lower than the current threshold, it is determined whether the discharge current exceeds the preset release threshold. If the discharge current does not exceed the preset release threshold, it indicates that the current discharge current is small. Therefore, when the battery voltage is high and the charging current is small, the probability of the battery being fully charged is high. However, due to the existence of the discharge current, the charging current may not meet the stop charging judgment condition. The power management module will not stop the charging current. Therefore, the probability of floating charge is also high, and the main control chip needs to turn off the charging switch tube.

[0092] If the discharge current exceeds the preset release threshold, the power consumption in the lithium battery is large, the remaining power in the lithium battery is small, and the probability of floating charge is low, so the charging switch tube can be left open. However, when the charging switch tube is in the off state, its internal parasitic diode has a certain forward conduction voltage drop, and this voltage drop will cause a certain amount of energy loss when current flows through it. The greater the discharge current, the greater the loss caused by this voltage drop. Therefore, when the discharge current exceeds the preset release threshold, the charging switch tube needs to be turned on to avoid power loss.

[0093] S305: Control the lithium battery protection circuit to be in a preset floating charge protection state and turn off the charging switch tube.

[0094] In a specific implementation scenario, the discharge current does not exceed the preset threshold value, so the lithium battery protection circuit is controlled to be in a preset floating charge protection state, and the charging switch tube is turned off.

[0095] S306: Control the lithium battery protection circuit to exit the preset floating charge protection state and turn on the charging switch tube.

[0096] In a specific implementation scenario, the discharge current exceeds a preset threshold value, so the lithium battery protection circuit is controlled to exit the preset floating charge protection state and turn on the charging switch tube.

[0097] It can be seen from the above description that in this embodiment, when the battery voltage exceeds the voltage threshold and the charging current is lower than the current threshold, it is determined whether the discharge current exceeds the preset release threshold. If the discharge current does not exceed the preset release threshold, the charging switch tube is turned off, which can effectively avoid the floating charge phenomenon and ensure the safety of lithium battery use. If the discharge current exceeds the preset release threshold, it can effectively avoid resource waste and improve energy utilization.

[0098] See also Figure 5 , Figure 5 1 is a flow chart of a fourth embodiment of a lithium battery anti-floating charge method provided by the present invention. The lithium battery anti-floating charge method provided by the present invention comprises the following steps:

[0099] S401: Obtaining battery information of a lithium battery through a sampling circuit, where the battery information includes at least one of a battery voltage, a charging current, and a discharging current.

[0100] S402: Determine whether the lithium battery is in a state of charging and discharging based on the management information; if not, execute step S403.

[0101] In a specific implementation scenario, if the lithium battery is in a single discharge state or a single charge state, the floating charge problem usually does not occur. The charging and discharging of the lithium battery are performed separately, and there is no simultaneous charging and discharging, so the floating charge problem that may occur in the state of charging and discharging at the same time will not occur.

[0102] In the single discharge state, the battery is only in the discharge state, and there is no charging process. In this case, the chemical reaction inside the battery will cause the release of charge, and the battery voltage will gradually decrease during the discharge process. At this time, there is no charging current, so there will be no floating charge.

[0103] In the single charging state, the battery is only in the charging state, and there is no discharge process. The charger will provide current for charging according to the battery status. Once the battery is full, the charging current will be low enough to meet the conditions for stopping charging and judging fullness. The lithium battery protection chip will stop the charging current from flowing to the lithium battery to avoid overcharging and floating charging.

[0104] Therefore, if the lithium battery is in a single discharge state or a single charge state, the charging switch tube does not need to be turned off, but needs to be in the on state. When the lithium battery is in a single charge state, if the charging switch tube is in the off state, the lithium battery cannot be charged, so it is necessary to keep the charging switch tube in the on state. When the lithium battery is in a single discharge state, the discharge current is large, and turning off the charging switch tube will cause a waste of power, so it is necessary to keep the charging switch tube in the on state.

[0105] S403: Determine whether the lithium battery protection circuit is in a preset floating charge protection state. If yes, execute step S404.

[0106] In a specific implementation scenario, it is determined whether the lithium battery protection circuit is in a preset floating charge protection state, that is, whether the charging switch tube is in the off state. Whether the charging switch tube is in the off state is determined by reading the control state of the control pin connected to the main control chip and the charging switch tube (currently in a high / low level state). In other implementation scenarios, a protection flag is preset in the main control chip, and the protection flag is set after the lithium battery protection circuit is controlled to be in a preset floating charge protection state; the protection flag is set to zero after the lithium battery protection circuit is controlled to exit the preset floating charge protection state, so the on / off state of the current charging switch tube can be determined by reading the value of the protection flag.

[0107] S404: Control the lithium battery protection circuit to exit the preset floating charge protection state and turn on the charging switch tube.

[0108] In a specific implementation scenario, the lithium battery protection circuit is in a preset floating charge protection state, and the charging switch tube is in a closed state. Therefore, the lithium battery protection circuit is controlled to exit the preset floating charge protection state and turn on the charging switch tube to ensure smooth charging / discharging operations of the lithium battery.

[0109] From the above description, it can be seen that when the lithium battery is in a single discharge state or a single charge state, controlling the lithium battery protection circuit to exit the preset floating charge protection state and turning on the charging switch tube can ensure that the charging / discharging operation of the lithium battery proceeds smoothly.

[0110] See also Figure 6 , Figure 6 1 is a flow chart of a fifth embodiment of a method for preventing floating charge of a lithium battery provided by the present invention. The method for preventing floating charge of a lithium battery provided by the present invention comprises the following steps:

[0111] S501: Acquire battery information of a lithium battery through a sampling circuit, where the battery information includes at least one of a battery voltage, a charging current, and a discharging current;

[0112] S502: Obtain management information of the power management module, and determine whether the lithium battery is in a state of simultaneous charging and discharging based on the management information; if so, execute step S503; if not, execute step S509.

[0113] S503: Determine whether the lithium battery protection circuit is in a preset floating charge protection state. If not, execute step S504; if so, execute step S508.

[0114] S504: Determine whether the battery voltage exceeds the voltage threshold and whether the charging current is lower than the current threshold. If so, execute step S505.

[0115] S505: Determine whether the discharge current exceeds a preset release threshold. If not, execute step S506.

[0116] S506: Control the lithium battery protection circuit to be in a preset floating charge protection state and turn off the charging switch tube.

[0117] S507: Determine whether the discharge current exceeds a preset release threshold. If yes, execute step S508.

[0118] S508: Control the lithium battery protection circuit to exit the preset floating charge protection state and turn on the charging switch tube.

[0119] S509: Determine whether the lithium battery protection circuit is in a preset floating charge protection state. If so, execute step S508.

[0120] The above steps have been described in the above embodiments and will not be repeated here.

[0121] See also Figure 7 , Figure 7 The lithium battery protection system 20 includes a sampling module 21 , a status module 22 , a safety module 23 , and a control module 24 .

[0122] The sampling module 21 is used to obtain the battery information of the lithium battery through the sampling circuit, and the battery information includes at least one of the battery voltage, charging current, and discharging current; the status module 22 is used to obtain the management information of the power management module, and judge whether the lithium battery is in a charging and discharging state based on the management information; the safety module 23 is used to judge whether the battery voltage exceeds the voltage threshold and whether the charging current is lower than the current threshold when the lithium battery is in the charging and discharging state; the control module 24 is used to control the lithium battery protection circuit to be in a preset floating charge protection state and turn off the charging switch tube when the battery voltage is higher than the preset voltage threshold and the charging current is lower than the current threshold.

[0123] The safety module 23 is also used to determine whether the discharge current exceeds a preset release threshold. If so, the lithium battery protection circuit is controlled to exit the preset floating charge protection state and turn on the charging switch tube.

[0124] The safety module 23 is also used to determine whether the discharge current exceeds a preset release threshold. If not, the lithium battery protection circuit is controlled to be in a preset floating charge protection state and the charging switch tube is turned off.

[0125] The safety module 23 is also used to determine whether the lithium battery protection circuit is in a preset floating charge protection state. If so, the step of determining whether the discharge current exceeds the preset release threshold and subsequent steps are executed; if not, the step of determining whether the battery voltage and charging current do not meet the preset safety conditions and subsequent steps are executed.

[0126] The safety module 23 is also used to set the protection flag after the step of controlling the lithium battery protection circuit to be in the preset floating charge protection state; and to set the protection flag to zero after the step of controlling the lithium battery protection circuit to exit the preset floating charge protection state. The step of determining whether the lithium battery protection circuit is in the preset floating charge protection state includes: determining whether the protection flag is in the set state.

[0127] The safety module 23 is also used to determine whether the lithium battery protection circuit is in a preset floating charge protection state when the lithium battery is in a single discharge state or a single charge state; if so, the lithium battery protection circuit is controlled to exit the preset floating charge protection state and turn on the charging switch tube.

[0128] From the above description, it can be seen that in this embodiment, when the lithium battery is in a state of charging and discharging, when the power management module is fully charged, the charging current does not meet the full charge judgment condition due to the presence of the load and cannot stop charging. The main control chip turns off the charging switch tube to avoid the floating charge phenomenon in time, effectively ensuring the safe use of the lithium battery and extending its service life. There is no need to add an additional high-current switch MOS tube to the main current circuit, which effectively reduces the control cost.

[0129] The present invention also provides a power supply device. The power supply device includes a processor and a memory. The processor is coupled to the memory. A computer program is stored in the memory, and the processor executes the computer program when working to implement the above method. The detailed steps can be found above and will not be repeated here.

[0130] The present invention also provides a computer-readable storage medium. The computer-readable storage medium stores at least one computer program, which is used to be executed by a processor to implement the above method. The detailed steps can be referred to above and will not be repeated here. In one embodiment, the computer-readable storage medium can be a storage chip, a hard disk, or a mobile hard disk or a USB flash drive, an optical disk, or other readable and writable storage tools in a terminal, or a server, etc.

[0131] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0132] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0133] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. For those skilled in the art, the technical solutions described in the above embodiments can be modified, or some of the technical features therein can be replaced by equivalents; and all these modifications and replacements should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preventing floating charge of a lithium battery, characterized in that: Applicable to a lithium battery power supply system, the lithium battery power supply system comprising a lithium battery, a lithium battery protection circuit and a system main circuit; The lithium battery protection circuit comprises a lithium battery protection chip and a charging switch tube and a discharging switch tube connected to the lithium battery protection chip, wherein the charging switch tube is connected to the lithium battery, and the discharging switch tube is connected to the lithium battery through the charging switch tube; The main circuit of the system includes a main control chip, and a sampling circuit and a power management module connected to the main control chip, the power management module is used to manage the input and output current of the lithium battery power supply system, the main control chip is connected to the charging switch tube, and the sampling circuit is connected to the charging switch tube; The lithium battery anti-floating charge method comprises the following steps: Acquiring battery information of the lithium battery through the sampling circuit, wherein the battery information includes at least one of battery voltage, charging current, and discharging current; Acquire management information of the power management module, and determine whether the lithium battery is in a state of charging and discharging based on the management information; If yes, determining whether the battery voltage exceeds a voltage threshold and whether the charging current is lower than a current threshold; If so, the lithium battery protection circuit is controlled to be in a preset floating charge protection state, and the charging switch tube is turned off.

2. The method for preventing floating charge of a lithium battery according to claim 1, characterized in that: Before the step of determining whether the battery voltage exceeds a voltage threshold and whether the charging current is lower than a current threshold, the method further comprises: It is determined whether the discharge current exceeds a preset release threshold value. If so, the lithium battery protection circuit is controlled to exit a preset floating charge protection state and the charging switch tube is turned on.

3. The method for preventing floating charge of a lithium battery according to claim 2, characterized in that: Before the step of controlling the lithium battery protection circuit to be in a preset floating charge protection state, the method includes: It is determined whether the discharge current exceeds a preset release threshold value. If not, the lithium battery protection circuit is controlled to be in a preset floating charge protection state, and the charging switch tube is turned off.

4. The method for preventing floating charge of a lithium battery according to claim 2, characterized in that: Before the step of determining whether the discharge current exceeds a preset release threshold, the method includes: Determine whether the lithium battery protection circuit is in the preset floating charge protection state, and if so, execute the step of determining whether the discharge current exceeds a preset release threshold, and subsequent steps; If not, the step of determining whether both the battery voltage and the charging current do not meet the preset safety condition and subsequent steps are performed.

5. The method for preventing floating charge of a lithium battery according to claim 4, characterized in that: A protection flag is preset, and after the step of controlling the lithium battery protection circuit to be in a preset floating charge protection state, the method includes: Setting the protection flag; After the step of controlling the lithium battery protection circuit to exit the preset floating charge protection state, the method further comprises: Setting the protection flag to zero; The step of determining whether the lithium battery protection circuit is in the preset floating charge protection state comprises: It is determined whether the protection flag is in a set state.

6. The method for preventing floating charge of a lithium battery according to claim 1, characterized in that: After the step of judging whether the lithium battery is in a state of charging and discharging based on the management information, the method further comprises: If the lithium battery is in a single discharge state or a single charge state, determining whether the lithium battery protection circuit is in the preset floating charge protection state; If so, the lithium battery protection circuit is controlled to exit the preset floating charge protection state and the charging switch tube is turned on.

7. A lithium battery power supply system, characterized in that: Used to implement the lithium battery anti-floating charge method according to any one of claims 1 to 6; The lithium battery power supply system comprises a lithium battery, a lithium battery protection circuit and a system main circuit; The lithium battery protection circuit comprises a lithium battery protection chip and a charging switch tube and a discharging switch tube connected to the lithium battery protection chip, wherein the discharging switch tube is connected to the lithium battery, and the charging switch tube is connected to the lithium battery through the discharging switch tube; The system main circuit includes a main control chip and a sampling circuit connected to the main control chip, the main control chip is connected to the charging switch tube, and the sampling circuit is connected to the charging switch tube.

8. A lithium battery protection system, characterized in that: The lithium battery power supply system according to claim 7 comprises: A sampling module, used to obtain battery information of the lithium battery through a sampling circuit, wherein the battery information includes at least one of a battery voltage, a charging current, and a discharging current; A status module, used to obtain management information of the power management module, and determine whether the lithium battery is in a state of charging and discharging based on the management information; A safety module, used to determine whether the battery voltage exceeds a voltage threshold and whether the charging current is lower than a current threshold when the lithium battery is in a state of charging and discharging; The control module is used to control the lithium battery protection circuit to be in a preset floating charge protection state and turn off the charging switch tube when the battery voltage is higher than a preset voltage threshold and the charging current is lower than a current threshold.

9. A power supply device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that: A computer program is stored, and when the computer program is executed by a processor, the processor is caused to execute the steps of the method according to any one of claims 1 to 6.

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