Anna Sargent , Reporter

Young people are hacking their used disposable vapes to wring more use out of them, in a growing trend that has parents and emergency services worried.

Fire and Emergency said the DIY method to prolong the life of vaping devices - opening them up and exposing the battery - posed serious fire and injury risks.

An Auckland mother, whom RNZ agreed not to name, said she was shocked to find her daughter had been doing it after finding broken USB adapters around her house.

"I found out that she had been trying to recharge single-use vapes. I'm gutted, just pure frustration from a parent - how do you stop them from doing it?"

She said she knew her 15-year-old had a vaping problem, but did not know she had been resorting to this to get her fix.

And she was not the only one. Multiple posts in the 1800-strong Vape-Free Kids NZ Facebook were from other parents who had made similar discoveries.

One mother in the Far North described how her 15-year-old son had been in a downward spiral of addiction since he started vaping a year ago.

"He was almost demanding from us that we buy him vapes, that we buy him fluids - which we didn't do - but it got to the point where it felt like, this is what you see hardcore drug addicts doing.

"Then earlier this year we kept finding the split wires in his room, so he was trying to recharge disposables."

She said the household had to hide wires and scissors, and they tried warning him about the danger.

"We talked to him, saying, 'Actually, you've got a lithium-ion battery in there, if it explodes it's going to explode in your face and it could set the house on fire'."

And that was a real danger. Fire and Emergency risk reduction and investigations manager Peter Gallagher said there had been an increase in the number of fires resulting from lithium-powered devices.

Gallagher said young people were relying on sources such as YouTube tutorials to recharge disposable vapes, but messing with lithium-ion batteries posed serious fire and injury risks.

"We are aware that this is a bit of a growing trend particularly overseas, and obviously with the internet that information comes to New Zealand very quickly.

"When people are manufacturing their own charger they're cutting out some of the regulators that prevent overcharging, and that can be catastrophic for the battery."

He warned this risked the batteries exploding, or causing a fire that would be very difficult to extinguish.

Vaping can be an alternative to smoking cigarettes. Photo: 123rf

"They don't burn necessarily for a long time, but they burn with a lot of heat and so anything around them is ignited."

Electrical and electronics engineer Dave Chisholm echoed this concern.

"It's very dangerous because you're talking about charging a battery using an unspecified or uncontrolled method.

"I was a bit horrified to find that kids were basically just grabbing something that delivers power and feeding it into a vape without any knowledge of the consequences, should what they're doing result in overcharging the battery."

The Vaping Industry Association of New Zealand said the issue of vapers making home-made chargers was confined to cheaply made disposable devices, which were able to be broken into to gain access to the battery.

It believed all vaping products should have sealed batteries - rather than replaceable ones - to prevent this type of risky DIY from happening.

This story was originally published by RNZ