It’s the latest in a string of fires across the capital that have been linked to e-bikes or e-scooters, prompting fresh warnings about online battery purchases.
The blaze started in a garage on High Road on Friday morning and destroyed a roof terrace and part of a first-floor studio flat.
Investigators believe the incident was accidental and involved an e-bike.
London Fire Brigade said there has been a rise in e-bike and e-scooter fires caused by faulty batteries that have been bought online.
Some do not meet the correct safety standards, it warned.
“When these batteries and chargers fail, they do so with ferocity and because the fires develop so rapidly, the situation can quickly become incredibly serious,” a spokesperson said.
“Lithium-ion batteries are susceptible to failure if incorrect chargers are used and there is a significant risk posed by e-bikes which have been converted.”
E-bike owners are advised to store and charge batteries in a safe location, such as a shed or garage, and to make sure there is a smoke alarm fitted.
“We know this won’t be possible for everyone, so if you are charging them indoors, please follow our advice on using safe charging and ensure everyone in your home knows what to do in the event of a fire,” the spokesperson said.
“We would also suggest people try not to charge them when they are asleep, so that if there is an issue they can react quickly.”
Around 25 firefighters responded to the North Finchley incident at around 5.15am. There were no reports of injuries.
Firefighters have been called to more than 130 fires involving the type of batteries used in e-bikes and e-scooters in London in little over a year.
A large fire in a high-rise block of flats in Shepherd’s Bush in June was believed to be started by an e-bike charging.
Transport using lithium-ion batteries has been banned from all parliamentary buildings. E-scooters can not be taken on the Tube or London buses following several alarming blazes.