Images captured inside the Trinity centre in Leeds show the man casually unaware of the plume of smoke coming from his pocket until it begins fizzing violently, emitting a bright light as it explodes and sending shoppers scampering for safety.
West Yorkshire Fire and Rescue Service said the explosion occurred when a spare lithium-ion battery in the man’s pocket came into contact with another metal item, such as coins or keys.
The man was left with slight injuries and needed first aid treatment.
Fire investigator Jamie Lister said: “This footage clearly shows the dangers of storing batteries alongside any metal objects, be it keys, coins, or even your phone if it has a metal case.
“This is not the first time we have seen injuries caused by a lithium-ion battery exploding whilst being carried in someone’s pocket. We really want the public to understand the risks which can be easily avoided.
“There does not need to be a fault with the battery, the problem is the incorrect storage of the batteries.”
E-cigarette users have been warned to carry batteries in a plastic case to prevent them short circuiting.
Mr Lister said: “There has been a marked increase in the number of fires we have seen, attributable to the incorrect storage of batteries.
“The use of rechargeable lithium-ion batteries is now commonplace in modern society and that’s why we want people to be vigilant because a simple mistake could have a devastating consequence.”