Six fire engines and around 40 firefighters were called to a fire at a hostel on Arlington Road in Camden.
Firefighters tackled a fire on the second floor of a six-storey building, part of one bedroom was damaged by the fire. One man was treated at the scene by London Ambulance Service crews for smoke inhalation.
The Brigade's Fire Investigators believe the fire was accidental and caused by the failure of a lithium-ion battery used for an electric bicycle.
A London Fire Brigade spokesperson said: “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 and charge them safely.
"Unplug devices once they have finished charging and make sure you use the right charger for your device.
The Brigade was called at 1654 and the fire was under control by 1758. Fire crews from Kentish Town, Euston, Soho, Holloway and Paddington fire stations attended the scene.