An e-bike burst into flames last night, after overcharging in a house at Merewether.
The battery had been on charge in the Macquarie Street home when it exploded at about 11pm, sparking a fire on the second level of the three-storey home.
It took Fire and Rescue NSW crews about two hours to put the fire out.
The second and third levels of the home were seriously damaged, and a man inside the house suffered mild smoke inhalation.
That man was asleep at the time but a neighbour heard the fire alarm and went to investigate, waking him up and getting him out of the home safely.
The incident has sparked another warning from firefighters about the dangers of overcharging batteries and leaving them unattended.