1. Why does a battery sometimes reach zero voltage (low voltage)? And how can this be resolved?
1) Check if the battery has been short-circuited, over-discharged, or reverse-charged (reversing the positive and negative terminals of the battery or the charger will force over-discharge when the battery is being charged); check if the electrical circuit is working properly; check if there are any burn marks on the spot-welded battery.
2) Whether the battery has been continuously overcharged with a high rate and large current, causing the battery core to expand and the internal positive and negative terminals to make direct contact and short circuit.
Solution:
1) Understand the specific usage of the customer's batteries;
2) Charge a battery of the same type and connect it to the appliance to determine if the appliance functions properly;
3) Charge the battery at 1C for 30 minutes, then leave it open for about 10 minutes. If the open-circuit voltage stabilizes within the battery's normal voltage range, the battery can be considered to have returned to normal. If the battery is damaged, the voltage cannot be restored. If this phenomenon occurs before the battery has been used and the voltage cannot be restored by 1C charging, further analysis by a professional technician is required.
4) We can recommend that customers choose batteries with protective electronic components or integrated circuits such as fuses and temperature switches (which disconnect the circuit in case of overcurrent charging and discharging, short circuit, overcharge, over-discharge, and reverse charging, thereby protecting 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 could be causing the battery/battery pack to fail to charge?
1) Check if the battery or battery pack is a zero-voltage, high-internal-resistance battery;
2) Check the battery pack connections, electronic components, and protection circuits for any abnormalities;
3) Check whether the charging device or charging circuit outputs charging voltage/current during the charging process;
4) Is the ambient temperature too high, causing low charging efficiency? (The optimal temperature should not exceed 40℃).
Solution:
1) Understand the customer's specific usage and conditions of the battery;
2) Connect a battery of the same model in series with a multimeter (current setting) to charge the circuit, and judge whether the charging equipment is normal based on the charging current value.
3) Analysis and processing of repeated single-cell zero-voltage steps;
4) We recommend that customers choose charging equipment or charging circuits with better stability.
3. What could be causing the battery/battery pack to fail to discharge?
Phenomenon: After charging, when installed in a device, the device cannot work, and the open-circuit voltage of the battery pack does not change or changes only slightly.
1) Check if the battery/battery pack has zero voltage; high internal resistance battery.
2) Check for damage to the internal electronic components and protection circuits of the battery pack;
3) Check if the equipment's discharge circuit is normal.
Solution:
1) Connect a fully charged battery/battery pack of the same type to the device and check if the device works properly;
2) Use a multimeter to check whether the internal electronic components and protection circuits of the battery are normal.
3) Analysis and processing of repeated single-cell zero-voltage steps;
4) If the problem is due to a faulty discharge circuit in the appliance, it is recommended that the customer repair or replace the appliance promptly.
5) If the customer has not modified the battery pack themselves, a specialized technician is required to conduct further analysis.
4. What factors might shorten battery life?
1) Whether the customer's charger or charging circuit is compatible with the battery and whether the output voltage/current is stable;
2) Whether the battery/battery pack is used in accordance with the SPEC requirements (e.g., the environment for battery use and storage);
3) Whether the type of battery used by the customer is consistent with the requirements of the customer's equipment.
4) Are there any batteries/battery packs that have been continuously overcharged or over-discharged?
Solution:
1) Understand the specific usage of the battery;
2) Check the nominal rated current and voltage on the charger's plaque;
3) Use a multimeter connected in series with the battery to charge the battery and check if the charging current is too high.
4) It is recommended to use a charger or charging circuit that is compatible with the battery/battery pack and has a more stable charging circuit, as well as a battery that is compatible with the device;
5) Customers are advised to use the battery/battery pack as required, and to avoid overcharging, reverse charging, or over-discharging as much as possible;
5. What is overcharging? What are the adverse consequences of overcharging? How can it be prevented?
In theory, when a Li-ion battery is charged under constant current and constant voltage at a certain rate, if the charging is switched to constant voltage 4.2V, and the current in the charging circuit is 0.01C, the constant voltage charging state is still in progress, which is considered overcharge.
Overcharging can lead to leakage, deformation, fire, and, after the constant voltage fails, an explosion can occur as the voltage increases with charging (generally limited to 6.0V). It is one of the important reasons for damaging battery performance.
Adding a PCB board to the outside of the battery, or setting up protective circuitry and/or a time limit device (i.e., a charging limit of 2.5 hours) in the charger to prevent overcharging can achieve the purpose of prevention and protection.
6. What is over-discharge? What are the adverse consequences of over-discharge? How can it be prevented?
When a battery is discharged at a constant current rate at a certain rate, if the discharge continues even when the battery voltage reaches 2.75V, this is called over-discharge.
Over-discharge can lead to leakage, zero voltage, and negative voltage, which is one of the important reasons for damaging battery performance.
Add a PCB board to the outside of the battery or design protection circuits and/or time-limiting devices in the charger to prevent over-discharge.
7. Under what circumstances can a battery explode? How can it be prevented?
Battery explosions can be caused by the following reasons:
1) An external short circuit exceeds the battery's tolerance limit;
2) Overcharging. The charging voltage exceeds the limit (generally not exceeding 6V);
3) Circuit board failure;
4) Temperature too high (above 150℃);
