Why 18650 Battery Would Explode?

18650 batteries can potentially explode or catch fire due to a phenomenon known as “thermal runaway.” Thermal runaway is a chain reaction that occurs when the internal temperature of the battery rises uncontrollably, leading to the release of gas and a rapid increase in pressure. This can result in the battery casing rupturing or bursting, causing an explosion or fire.

Several factors can contribute to thermal runaway in 18650 batteries:

1. Overcharging: Charging a lithium-ion battery beyond its maximum voltage can lead to the buildup of excess heat and trigger thermal runaway.
2. Overdischarging: Fully discharging a lithium-ion battery can cause the voltage to drop below a safe threshold, leading to the battery’s internal chemistry becoming unstable.
3. Short-circuiting: If the positive and negative terminals of the battery come into direct contact, it can create a short circuit, causing rapid discharge and generating heat.
4. Physical damage: Punctures, dents, or other physical damage to the battery can compromise the internal components and lead to a thermal runaway event.
5. High temperatures: Exposing the battery to high ambient temperatures or leaving it in a hot environment can accelerate the breakdown of internal materials and trigger thermal runaway.
6. Poor quality or counterfeit batteries: Low-quality or counterfeit 18650 batteries might not have proper safety features or adhere to quality standards, making them more susceptible to thermal runaway.

Safety guidelines to prevent 18650 battery explosions or fires:

1. Use quality batteries from reputable manufacturers and avoid cheap, unknown brands.
2. Avoid overcharging or overdischarging the batteries; use chargers with overcharge protection.
3. Inspect batteries regularly for any signs of damage, and replace damaged batteries immediately.
4. Store batteries in a cool, dry place away from direct sunlight and heat sources.
5. Do not expose batteries to extreme temperatures or other harsh conditions.
6. Always use appropriate battery holders or cases to prevent physical damage and short circuits.
7. Never expose batteries to water or other liquids.
8. Dispose of old or damaged batteries properly at designated recycling centers.

Following these precautions can significantly reduce the risk of battery explosions and ensure safe usage of 18650 batteries.