Four fire engines and around 25 firefighters tackled a blaze at a house in Warwick Road, Rainham.
All of the first floor, part of the second floor and a small part of a neighbouring property were damaged by fire. One woman was treated at the scene by London Ambulance Service.
The fire is believed to have been caused by a battery pack.
The Brigade was called at 1841 and the fire was under control by 2010. Crews from Wennington, Dagenham, Barking and Hornchurch fire stations attended the incident.