Four fire engines and around 25 fire engines were called to a fire in a garden shed at the rear of Mosul Way in Bromley.
A garden shed containing two mobility scooters was completely destroyed by fire.
The cause of the fire is believed to be due to the catastrophic failure of lithium batteries in the mobility scooters.
A London Fire Brigade spokesperson said: “Lithium batteries are susceptible to failure if incorrect chargers are used, so it’s important to always use the correct charger for the product and buy an official one from a reputable seller.
"You should unplug your charger when you have finished using it and we would advise not to leave it unattended or charging while people are asleep.
“Batteries can present a fire risk if they’re over-charged, short circuited, submerged in water or damaged, so it’s really important to protect them against being damaged too.
“Try to ensure they are not getting knocked around while in use or while being carried as this can increase the chance of damage to cells."
The Brigade's 999 Control officers were first called at 1653 and the fire was under control by 1731. Fire crews from Bromley and Orpington fire stations were in attendance.