Four fire engines and around 25 firefighters attended a fire at a residential block on Bradwell Close in South Woodford.
A room in a second-floor flat was destroyed by fire. Several people were treated at the scene by London Ambulance Service.
The fire is believed to have been caused by the failure of a lithium-ion battery.
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 received the first of nine calls about the fire at 0755 and Control Officers mobilised crews from Walthamstow, Leyton, Woodford and Leytonstone fire stations to the scene. The fire was extinguished by 0828.