Can a battery explode?
Lead-acid batteries can source of fuel for external explosions or explode internally. Charging a wet lead-acid battery produces hydrogen and oxygen gasses as electrolysis of the water occurs. That is why charging needs to occur in well ventilated areas. While spark retarding vent caps help prevent external battery explosions, a spark can occur when jumping, connecting or disconnecting charger or battery cables and ignite the gas causing an explosion. From the U.S. Department of Energy, DOE-HDBK-1084-95, “Precautions must be routinely practiced to prevent explosions from ignition of the flammable gas mixture of hydrogen and oxygen formed during overcharge of lead-acid cells. The maximum rate of formation is 0.42 L of hydrogen and 0.21 L of oxygen per ampere-hour overcharge at standard temperature and pressure. The gas mixture is explosive when hydrogen in air exceeds 4% by volume.” Less common internal explosions usually occur while starting the engine or if the battery is rapidly heate
