What are the frequently asked questions about the use and maintenance of lithium-ion batteries

1. Why is there a battery zero voltage (low voltage)? And how to deal with it? 1) Whether the battery has suffered an external short circuit or over-discharge or reverse charging (reversely connect the positive and negative electrodes of the battery or the positive and negative electrodes of the charger, the battery is equivalent to forced over-discharge when charging); whether the electrical circuit is normal; whether the spot welding product battery There are burn marks. 2) Whether the battery is continuously overcharged by high-rate and high-current, which causes the battery core to expand, and the internal positive and negative electrodes are directly contacted and short-circuited. Solution: 1) Understand the specific usage of the customer’s battery; 2) Recharge the battery of the same model and connect it to the electrical appliance to determine whether the electrical appliance is normal; 3) Charge the battery with 1C current for 30 minutes and leave it open for about 10 minutes, such as The open circuit voltage of the battery is stable within the normal voltage range of the battery, and the battery can basically return to normal. If the battery has been damaged, the voltage cannot be restored; if the battery is not used and this phenomenon occurs, the 1C charging voltage cannot be restored, and further analysis by professional and technical personnel is required. 4) Customers can be advised to choose batteries with protective electronic components such as fuse, temperature switch, or integrated circuit (disconnect the circuit in the case of overcurrent charging and discharging and short circuit, overcharging, overdischarging, and reverse charging, so as to protect the battery from damage). 5) Customers are advised to pay attention to the spot welding current and the distance between the welding pins. 2. What happens if the battery/battery pack cannot be charged? 1) Check whether the battery or battery pack is a zero-voltage, high internal resistance battery; 2) Check the connection of the battery pack and whether the electronic components and protection circuit are abnormal; 3) Check whether the charging equipment or the charging circuit has a charging voltage under the charging state /Current output; 4) Whether the ambient temperature is too high and the charging efficiency is low (the best temperature should not exceed 40℃); Solution: 1) Understand the customer’s specific use of the battery and conditions of use; 2) Take the same type of battery and The multimeter (current file) is connected in series to the circuit for charging, and the charging device is judged according to the charging current value. 3) Repeat the analysis and processing of the single battery zero voltage step; 4) It is recommended that customers choose charging equipment or charging circuits with better stability; 3. What happens if the battery/battery pack can't discharge? Phenomenon: After charging, the device cannot work, and the open circuit voltage of the battery pack does not change or changes little after being loaded into the device. 1) Check whether the battery/battery pack is a zero-voltage, high-resistance battery; 2) The battery pack is connected to electronic components, Whether the protection circuit is damaged; 3) Check whether the discharge circuit of the equipment is normal. Treatment method: 1) Use a fully charged battery/battery pack of the same type to connect to the device, and check whether the device is working properly; 2) Use a multimeter to check whether the electronic components and the protection circuit inside the battery are normal. 3) Repeat the analysis and treatment of the zero-voltage step of the single battery; 4) If the discharge circuit of the electrical appliance is abnormal, it is recommended that the customer repair and replace the electrical appliance in time; 5) If the customer does not modify the battery pack by himself, a dedicated technician is required. Further analysis. 4. What are the reasons that may shorten the service life of the battery? 1) Whether the customer's charger or charging circuit matches the battery, and whether the output voltage/current is stable; 2) Whether the battery/battery pack is used in accordance with SPEC requirements (such as the use and storage environment of the battery, etc.); 3) The battery used by the customer Whether the variety is consistent with the customer's equipment requirements. 4) Whether there is continuous overcharge or overdischarge of the battery/battery pack; treatment method: 1) understand the specific usage of the battery; 2) check the nominal rated current and voltage of the charger chrome plate; 3) use a multimeter and the battery in series to charge the circuit , To detect whether the charging current is too large. 4) It is recommended to use a charger that matches the battery/battery pack and is more stable or a battery with a charging circuit that matches the equipment; 5) It is recommended that customers use the battery/battery pack as required to prevent overcharge, reverse charge or over discharge as much as possible ; 5. What is overcharge? What are the undesirable consequences of overcharging? How to prevent it? Theoretically, Li-ion batteries are charged at a constant current and constant voltage at a certain rate. After the charging is converted to constant voltage 4.2V charging, when the current in the charging circuit is 0.01C, the state of constant voltage charging is still in progress, that is, it is considered Is overcharged. Overcharging may cause liquid leakage, deformation, fire, and after constant voltage failure, the voltage will explode as the charging depth reaches a certain level (the general limit is 6.0V), which is one of the important reasons for impairing battery performance. Adding PCB board protection outside the battery, or setting a protection circuit and/or time limit device in the charger (that is, the charging limit is 2.5 hours) to prevent the battery from overcharging can achieve the purpose of prevention and protection. 6. What is over-discharge? What are the undesirable consequences of over-discharge? How to prevent it? The battery is discharged at a constant current at a certain rate. When the battery voltage reaches 2.75V, the discharge state is still continuing, that is, overdischarge. Over-discharge may cause leakage, zero voltage, and negative voltage, which is one of the important reasons that impair battery performance. Add a PCB board outside the battery or design a protection circuit and/or time limit device in the charger to prevent over-discharge. 7. Under what circumstances will the battery explode? How to prevent it? There are several reasons for battery explosion: 1) External short circuit exceeds the battery's tolerance limit; 2) Overcharge. The charging voltage exceeds the limit value (generally no more than 6V); 3) Circuit board failure; 4) The temperature is too high (over 150°C); Statement: Some pictures and content of articles published on this site are from the Internet. 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