Safe and reliable lithium battery pack equalizing charging system

Abstract

The invention discloses a safe and reliable lithium battery pack equalization charging system, which comprises a multi-battery equalization charging control system, the multi-battery equalization charging control system comprises a detection stage and an equalization stage, in the detection stage, a control chip is used for monitoring the voltage and temperature of each monomer in a battery pack in real time; the equalization stage is composed of an equalization circuit board, a control chip, a switch circuit and the like, a plurality of equalization circuit units are installed on the equalization circuit board, each equalization circuit unit is connected with one battery monomer, and the control chip in the detection stage periodically monitors the voltage difference between the battery monomers and controls the switch circuit to switch on the equalization circuit board. If the voltage difference exceeds a set threshold value, the control chip is in an equalization stage; the battery consistency can be improved, the service life of the battery can be prolonged, the safety can be improved, the energy storage efficiency can be ensured, the output power can be stabilized, the battery performance can be optimized, and the battery replacement period can be prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery pack charging, and in particular to a safe and reliable lithium battery pack balanced charging system. Background Art

[0002] Lithium battery packs are widely used in lithium battery applications. Single lithium batteries are connected in series and in parallel to form battery packs with different voltages and capacities.

[0003] However, after the batteries are connected in series, due to the differences in each battery, such as differences in battery manufacturing process, material properties, usage environment and aging degree, the voltage and capacity of each battery will gradually differ during the use of the battery. This difference will become larger and larger with the environment and time. During the charge and discharge process of the battery pack, due to the barrel effect, the single battery with the lowest capacity will limit the overall discharge and charge of the battery pack, ultimately resulting in a reduction in the overall capacity.

[0004] Therefore, we propose a safe and reliable lithium battery pack balanced charging system to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a safe and reliable lithium battery pack balanced charging system to solve the problem raised in the above background technology that during the charging and discharging process of the battery pack on the current market, due to the barrel effect, the single battery with the lowest capacity will limit the overall discharge and charging of the battery pack, ultimately resulting in a reduction in the overall capacity.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a safe and reliable lithium battery pack balanced charging system, including a multi-battery balanced charging control system, the multi-battery balanced charging control system includes a detection stage and a balanced stage, the detection stage uses a control chip to monitor the voltage and temperature of each battery cell in the battery pack in real time, the balanced stage is composed of a balanced circuit board, a control chip and a switch circuit, etc., a plurality of balanced circuit units are installed on the balanced circuit board, each balanced circuit unit is connected to a battery cell, the control chip periodically monitors the voltage difference between the battery cells in the detection stage, if the voltage difference exceeds a set threshold, the control chip will be balanced stage;

[0007] 1. The balanced charging stage uses lithium-ion battery pack balanced charging technology for charging:

[0008] (1) Constant shunt resistor equalization charging: A parallel equalization circuit is added to each single cell of the battery pack to achieve the purpose of shunt. When a battery reaches full charge first, the equalization device can prevent it from overcharging and convert the excess energy into heat energy, and then continue to charge the battery that is not fully charged;

[0009] (2) Switching on and off shunt resistors for balanced charging: Shunt resistors are used for balanced charging. The shunt resistors are not always in working state, but are switched on and off according to the charging status of the battery.

[0010] (3) Average battery voltage equalization charging: The equalization charging operation is performed by monitoring the average voltage of the battery pack. When the voltage of a battery cell deviates from the average voltage by more than a certain range, the battery will be charged or discharged to make its voltage approach the average voltage, thereby achieving voltage balance in the battery pack.

[0011] (4) Switched capacitor balanced charging: Buck converter balanced charging is achieved with the help of a buck converter. During the charging process, when the voltage of a battery cell reaches a certain value, the buck converter starts to work, adjusts the charging voltage of the battery cell, and processes the excess energy to achieve balanced charging of each battery cell in the battery pack;

[0012] (5) Inductor balanced charging: The energy storage and release characteristics of the inductor are used for balanced operation. During the charging process, the energy is transferred between different battery cells through the circuit connection between the inductor and the battery cell. When the voltage of a battery cell is too high, the inductor can absorb the excess energy and then release the energy to the battery cell with lower voltage, thereby achieving balanced charging of the battery pack;

[0013] 2. Balanced charging operation steps:

[0014] (1) Use a dedicated lithium battery balance charger to check the connection of the battery pack to ensure that the battery cells are firmly connected and the circuits are normal;

[0015] (2) Insert the balance charging port of the lithium battery pack into the corresponding port position of the charger, and correctly connect the positive and negative poles of the battery (such as T-head) to the OUTPUT port of the charger;

[0016] (3) The charger has a monitoring function that displays the voltage of each battery cell in real time. If the voltage of a battery cell is found to be abnormally high or the charging speed is abnormally fast, there may be a problem with the battery cell itself or a malfunction in the equalizing charging function. Charging needs to be stopped and checked in time.

[0017] (4) Check whether the voltage of the battery pack is balanced. If it is not balanced, further check the health of the charging equipment or the battery pack. After confirming that the battery pack is charged evenly and the charging is completed, disconnect the battery pack from the charger in the correct order;

[0018] 3. Balanced charging process protection:

[0019] During balanced charging, in addition to voltage balance control of battery cells, the battery temperature also needs to be monitored in real time. When the temperature exceeds a certain threshold, the charging strategy should be adjusted or charging should be stopped in time. In addition, the balanced charging circuit of lithium batteries is usually integrated into the battery management system (BMS), which will fully monitor and protect the battery's charging and discharging, overcurrent, short circuit and other states;

[0020] Preferably, the charger needs to match the type of battery pack. Different types of batteries have different charging characteristics. Using the wrong charger may cause battery damage or even cause safety problems.

[0021] Preferably, the equalizing charging is performed in an environment with a suitable temperature (usually about 0-40° C.) as much as possible. Too high or too low a temperature may affect the charging efficiency and equalizing effect of the battery.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) This safe and reliable lithium battery pack balanced charging system adopts an external voltage balanced control strategy based on a DC-DC converter. This strategy adjusts the charging voltage of the battery cells by controlling the DC-DC converter, transferring energy from the battery cells with high voltage to the battery cells with low voltage. At the same time, the BMS will also adjust the charging current according to the temperature of the battery to avoid overcharging the battery at high temperature. This balanced charging method can effectively improve the overall performance of the battery pack and extend the battery life.

[0024] (2) This safe and reliable lithium battery pack balanced charging system, when charging, the balanced charger will be connected to the battery pack through the battery balance interface, accurately monitor the voltage of each battery cell, and when the voltage is found to be unbalanced, it will adopt technologies such as constant shunt resistor balanced charging or switch capacitor balanced charging to achieve balanced charging of the battery pack;

[0025] (3) This safe and reliable lithium battery pack balanced charging system can improve battery consistency, extend battery life, enhance safety, ensure energy storage efficiency, stabilize output power, optimize battery performance, and extend battery replacement cycle. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The present invention provides a technical solution: a safe and reliable lithium battery pack balanced charging system, including a multi-battery balanced charging control system, the multi-battery balanced charging control system includes a detection stage and a balanced stage, the detection stage uses a control chip to monitor the voltage and temperature of each battery cell in the battery pack in real time, the balanced stage is composed of a balanced circuit board, a control chip and a switch circuit, etc., a plurality of balanced circuit units are installed on the balanced circuit board, each balanced circuit unit is connected to a battery cell, the control chip periodically monitors the voltage difference between the battery cells in the detection stage, if the voltage difference exceeds a set threshold, the control chip will be balanced stage;

[0028] 1. The balanced charging stage uses lithium-ion battery pack balanced charging technology for charging:

[0029] (1) Constant shunt resistor equalization charging: A parallel equalization circuit is added to each single cell of the battery pack to achieve the purpose of shunt. When a battery reaches full charge first, the equalization device can prevent it from overcharging and convert the excess energy into heat energy, and then continue to charge the battery that is not fully charged;

[0030] (2) Switching on and off shunt resistors for balanced charging: Shunt resistors are used for balanced charging. The shunt resistors are not always in working state, but are switched on and off according to the charging status of the battery.

[0031] (3) Average battery voltage equalization charging: The equalization charging operation is performed by monitoring the average voltage of the battery pack. When the voltage of a battery cell deviates from the average voltage by more than a certain range, the battery will be charged or discharged to make its voltage approach the average voltage, thereby achieving voltage balance in the battery pack.

[0032] (4) Switched capacitor balanced charging: Buck converter balanced charging is achieved with the help of a buck converter. During the charging process, when the voltage of a battery cell reaches a certain value, the buck converter starts to work, adjusts the charging voltage of the battery cell, and processes the excess energy to achieve balanced charging of each battery cell in the battery pack;

[0033] (5) Inductor balanced charging: The energy storage and release characteristics of the inductor are used for balanced operation. During the charging process, the energy is transferred between different battery cells through the circuit connection between the inductor and the battery cell. When the voltage of a battery cell is too high, the inductor can absorb the excess energy and then release the energy to the battery cell with lower voltage, thereby achieving balanced charging of the battery pack;

[0034] 2. Balanced charging operation steps:

[0035] (1) Use a dedicated lithium battery balance charger to check the connection of the battery pack to ensure that the battery cells are firmly connected and the circuits are normal;

[0036] (2) Insert the balance charging port of the lithium battery pack into the corresponding port position of the charger, and correctly connect the positive and negative poles of the battery (such as T-head) to the OUTPUT port of the charger;

[0037] (3) The charger has a monitoring function that displays the voltage of each battery cell in real time. If the voltage of a battery cell is found to be abnormally high or the charging speed is abnormally fast, there may be a problem with the battery cell itself or a malfunction in the equalizing charging function. Charging needs to be stopped and checked in time.

[0038] (4) Check whether the voltage of the battery pack is balanced. If it is not balanced, further check the health of the charging equipment or the battery pack. After confirming that the battery pack is charged evenly and the charging is completed, disconnect the battery pack from the charger in the correct order;

[0039] 3. Balanced charging process protection:

[0040] During balanced charging, in addition to voltage balance control of battery cells, the battery temperature also needs to be monitored in real time. When the temperature exceeds a certain threshold, the charging strategy should be adjusted or charging should be stopped in time. In addition, the balanced charging circuit of lithium batteries is usually integrated into the battery management system (BMS), which will fully monitor and protect the battery's charging and discharging, overcurrent, short circuit and other states;

[0041] The charger needs to match the type of battery pack. Different types of batteries have different charging characteristics. Using the wrong charger may cause battery damage or even cause safety issues.

[0042] Balanced charging should be performed in an environment with suitable temperature (usually around 0-40℃) as high or low temperature may affect the charging efficiency and equalization effect of the battery.

[0043] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0044] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A safe and reliable lithium battery pack balanced charging system, including a multi-battery balanced charging control system, characterized in that: The multi-battery balanced charging control system includes a detection stage and a balanced stage. The detection stage uses a control chip to monitor the voltage and temperature of each battery cell in real time. The balanced stage is composed of a balanced circuit board, a control chip and a switch circuit. A plurality of balanced circuit units are installed on the balanced circuit board. Each balanced circuit unit is connected to a battery cell. The control chip periodically monitors the voltage difference between battery cells in the detection stage. If the voltage difference exceeds a set threshold, the control chip will enter the balanced stage; 1. The balanced charging stage uses lithium-ion battery pack balanced charging technology for charging: (1) Constant shunt resistor equalization charging: A parallel equalization circuit is added to each single cell of the battery pack to achieve the purpose of shunt. When a battery reaches full charge first, the equalization device can prevent it from overcharging and convert the excess energy into heat energy, and then continue to charge the battery that is not fully charged; (2) Switching on and off shunt resistors for balanced charging: Shunt resistors are used for balanced charging. The shunt resistors are not always in working state, but are switched on and off according to the charging status of the battery. (3) Average battery voltage equalization charging: The equalization charging operation is performed by monitoring the average voltage of the battery pack. When the voltage of a battery cell deviates from the average voltage by more than a certain range, the battery will be charged or discharged to make its voltage approach the average voltage, thereby achieving voltage balance in the battery pack. (4) Switched capacitor balanced charging: Buck converter balanced charging is achieved with the help of a buck converter. During the charging process, when the voltage of a battery cell reaches a certain value, the buck converter starts to work, adjusts the charging voltage of the battery cell, and processes the excess energy to achieve balanced charging of each battery cell in the battery pack; (5) Inductor balanced charging: The energy storage and release characteristics of the inductor are used for balanced operation. During the charging process, the energy is transferred between different battery cells through the circuit connection between the inductor and the battery cell. When the voltage of a battery cell is too high, the inductor can absorb the excess energy and then release the energy to the battery cell with lower voltage, thereby achieving balanced charging of the battery pack; 2. Balanced charging operation steps: (1) Use a dedicated lithium battery balance charger to check the connection of the battery pack to ensure that the battery cells are firmly connected and the circuits are normal; (2) Insert the balance charging port of the lithium battery pack into the corresponding port position of the charger, and correctly connect the positive and negative poles of the battery (such as T-head) to the OUTPUT port of the charger; (3) The charger has a monitoring function that displays the voltage of each battery cell in real time. If the voltage of a battery cell is found to be abnormally high or the charging speed is abnormally fast, there may be a problem with the battery cell itself or a malfunction in the equalizing charging function. Charging needs to be stopped and checked in time. (4) Check whether the voltage of the battery pack is balanced. If it is not balanced, further check the health of the charging equipment or the battery pack. After confirming that the battery pack is charged evenly and the charging is completed, disconnect the battery pack from the charger in the correct order; 3. Balanced charging process protection: During balanced charging, in addition to voltage balancing control of battery cells, the battery temperature also needs to be monitored in real time. When the temperature exceeds a certain threshold, the charging strategy should be adjusted or charging should be stopped in time. In addition, the balanced charging circuit of lithium batteries is usually integrated into the battery management system (BMS). The BMS will fully monitor and protect the battery's charging and discharging, overcurrent, short circuit and other states.

2. A safe and reliable lithium battery pack equalization charging system according to claim 1, characterized in that: The charger needs to match the type of battery pack. Different types of batteries have different charging characteristics. Using the wrong charger may cause battery damage or even cause safety issues.

3. A safe and reliable lithium battery pack equalization charging system according to claim 1, characterized in that: The equalizing charge is performed in an environment with a suitable temperature (usually about 0-40° C.) as much as possible. Too high or too low a temperature may affect the charging efficiency and equalizing effect of the battery.