Authorities warn against charging e-scooters incorrectly after person critically injured in apartment fire

A person has critical injuries after an e-scooter caught fire inside an apartment in Wellington on Saturday night.

It's not clear what caused it to combust, but authorities are warning the public about the dangers of not charging the batteries properly.

On Sunday Tory Street looked normal but last night it was at the centre of a mini-explosion inside an apartment block.

"Initial investigations determined that that fire originated in and around an electric scooter that was being charged," said Fire and Emergency (FENZ) national risk reduction manager Peter Gallagher.

E-scooters and e-bikes are powered by lithium-ion batteries that need charging. But if it's done incorrectly they can catch fire or explode.

"Because there's so much energy in these batteries. They release that very, very quickly so they burn very, very hot," Gallagher said.

"If you use an incorrectly matched charger and it turns out you're putting in too much voltage or its a cheap charger and its not able to manage the voltage it's putting into the battery, it can destabilise the chemical compounds in the battery and those batteries to contain all the elements to self-combust," Electric Scooter Shop owner Jonno Leonard said.

Scooter explosions aren't common in New Zealand, but cost-conscious Kiwis can be guilty of using dangerous chargers.

"People are buying cheap chargers off Alibaba, not knowing whether or not it will put out the correct voltage," said Leonard.

"As these items become more and more in our daily lives we are likely to see an increase," Gallagher said.

So to prevent fires, Leonard has some advice.

"Charge it in a well-ventilated area, don't leave it charging overnight, don't let the charger be covered," he said.

FENZ said ideally e-scooters and bikes should be charged away from living areas and under supervision. But if that isn't an option keep them away from escape routes.

"The worst thing that can happen is the scooter is between you and your exit and you have to get past a burning scooter or lithium-ion battery to get out of the house," Gallagher said.

Advice to avoid a repeat of what happened in central Wellington last night.