Four fire engines and around 25 firefighters tackled a fire at a hotel on Stockwell Street in Greenwich.
Most of a hotel room on the first floor of the building was damaged by fire. Around 50 residents and staff left the building before the Brigade arrived. A man was taken to hospital by London Ambulance Service crews.
The fire is believed to have been accidental and caused by lithium-ion batteries.
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 always make sure you use the right charger for your device.”
The Brigade was called at 1727 and the fire was under control by 1826. Fire crews from Greenwich, East Greenwich, Deptford and Lewisham fire stations attended the scene.