Four fire engines and around 25 firefighters were called to a fire in a flat in Kennet Square, Mitcham.
Part of a four-roomed flat on the third floor was damaged by fire. A woman and child left the flat before the Brigade arrived. There were no reports of any injuries.
The Brigade was called at 1410 and the fire was under control by 1454. Fire crews from Mitcham, Tooting and Wimbledon stations attended the incident.
The cause of the fire is believed to be a fault in a lithium ion battery.