1. The voltage is inconsistent, some of the voltage is low

1. Large self-discharge will cause low voltage

The self-discharge of the battery is large, so its voltage drops faster than other batteries. The low voltage can be eliminated by checking the stored voltage.

2. Uneven charging will cause low voltage

When charging the battery after the test, the battery cells cannot be uniformly charged due to the inconsistent contact resistance or the charging current of the test cabinet. The voltage difference measured during short-term storage (12 hours) is small, but the voltage difference is large during long-term storage. This low voltage has no quality problems and can be solved by charging. During the production process, it should be stored for more than 24 hours after charging to measure the voltage.

Second, the internal resistance is too large

1. Reasons for differences in testing equipment

If the detection accuracy is insufficient or the contact group cannot be eliminated, the internal resistance of the display will be too large. The principle of the AC bridge method should be used to test the internal resistance of the instrument.

2. Storage time is too long

Lithium battery storage time is too long, will cause excessive capacity loss, internal passivation and large internal resistance, which can be solved by charging and discharging activation.

3. Abnormal heating will cause larger internal resistance

Processing the battery (spot welding, ultrasonic, etc.) will cause abnormal heating of the battery, which will cause the separator to heat seal and the internal resistance will greatly increase.

3. Lithium battery expansion

1. Lithium battery swells when charging

When charging a lithium battery, the lithium battery will naturally expand, but generally no more than 0.1mm, but overcharging will cause the electrolyte to decompose, the internal pressure will increase, and the lithium battery will expand.

2. Expansion during processing

Normally, abnormal handling (such as short circuit, overheating, etc.) causes internal heating and decomposition and swelling of lithium batteries.

What are the advantages of polymer lithium batteries?

Polymer lithium battery is also called polymer lithium battery: Compared with the previous battery, it is a high-energy, miniaturized and lightweight battery. In terms of shape, polymer lithium batteries have ultra-thin characteristics that can meet the needs of certain products and can be made into batteries with certain shapes and capacities. In terms of safety, the outer packaging is aluminum-plastic packaging, which is different from the metal casing of liquid lithium batteries. Internal quality hazards can be immediately revealed through the deformation of the outer packaging. Once a safety hazard occurs, it will not explode, but will only expand. The theoretical small thickness of this battery can reach 0.5mm.