Analysis of the causes of lithium battery explosions
In general, people do not associate cell phone explosions with batteries. But in reality, the real cause of cell phone explosions is the battery. Professionals believe that the root cause of battery explosions is the use of counterfeit and substandard products. Experts said that most of the batteries currently in use are lithium batteries, and there are about three reasons for battery explosions:
(1) The reasons for the battery itself. Due to internal defects in the battery, the battery itself explodes without charging or discharging;
(2) The battery core is overcharged for a long time. Lithium batteries can discharge instantly and generate a large amount of current under special conditions or environments of temperature, humidity, poor contact, etc., causing spontaneous combustion or explosion;
(3) Short circuit. It's less likely. Additionally, consumers placing their cell phones near high temperature or flammable objects can also cause explosions. Before the cell phone battery is officially assembled, it must undergo professional performance testing. As a connection test module, the shrapnel microneedle module has a good conductive effect. The possible value range in the pitch field is between 0.15 and 0.4 mm. the test is stable, no needle breakage or stuck pin!
Take the example of a 3C lithium battery:
1. Continuous charging: a cell of fully charged battery 20 plus or minus 5C. . According to the manufacturer's regulations, it will not catch fire, explode or leak when charged for 28 consecutive days.
2. Standard vibra testtion: Fully charged battery cell 20 plus or minus 5C, amplitude 0.8MM, 1Hz/min, between 10-55Hz, three mutually perpendicular directions, each axis tested for 90 minutes. No fire, no explosion, no leak.
3. Temperature cycle: Fully charged cells are placed in a battery test box and the cells are subjected to the following cycle tests. A.) 75+2C4 hours B.) 20+5C2 hours C. )-202C2 hours D) 205C2 hours E. ) Repeat A to D 4 times. F) After 5 cycles, store for 7 days before testing.
4. External short circuit: If the fully charged battery core is 20+5C and 55+2C, short circuit with a resistor with a total resistance less than 100 milliohms, it will not will not catch fire or explode. .
5. Free fall: fully charged 20+5C battery core, fall from a height of 1 meter onto the cement floor in any direction to achieve impact,3 times in a row, without fire or explosion.
6. Mechanical vibration: fully charged battery cell 20+5C, maximum acceleration 125-175gn, 3 vibrations of the same intensity in 3 mutually perpendicular directions. No fire, no explosion, no leak.
7. High temperature: A fully charged battery core will not catch fire or explode if placed in an environment of 130 + 2 C for 10 minutes!
8. Battery core pressure: 20+5C, Use a force of about 13Kn on two planes to compress the fully charged battery core so that the longitudinal axis of the battery core is parallel to the plane. Once maximum pressure is reached, release it immediately. No fire, no explosion.
9. Low voltage: Fully charged battery cell maintains 20+5C, 11.6Kpa for 6 hours, no fire, no explosion, no leakage. 10. Overload: 20+5 C, thisllule of discharged battery is equal to 10V in heavy rain, charging current is equal to lrec, time is 2.13 CZ/rec, rec is equal to the constant current recommended by the manufacturer for charging. The unit is the Ampere. No fire, no explosion!
11. Forced discharge: 20+5C, the discharged battery core is discharged with a constant current of 1ItA for 90 minutes. No fire, no explosion!
The above standards are common for 3C lithium batteries in different testing environments. Stable current transmission is required during testing, and high-current shrapnel microneedle modules are used to maintain current conduction and signal. Transmission, playing a stable connection role.