With time, the batteries of the mod are bound to get old and be damaged. They may begin leaking or swelling and give problems when charging. When you begin to notice faults in charging or with the batteries, it is recommendable that you begin considering getting a replacement for the batteries. Some of the vape mods that explode usually have faulty batteries. Leaking batteries can cause an undesired connection or rust within the mods. Contact between the wires might then result in explosions. This is particularly more dangerous as the explosion can happen at any time, whether you are vaping, charging or just holding the device.