Backyard battery repairs named in NSW inquest into fatal e-bike fires

A NSW Coroners Court inquest has heard that unauthorised repairs and modifications to e-bike batteries are a recurring factor in serious lithium-ion fires, including a blaze that killed two women in a Teralba townhouse in February 2024.

Fire and Rescue NSW investigator Andrew Low told the court that backyard operators are soldering and swapping cells using parts bought online, often following YouTube tutorials. He said he had personally attended eight lithium-ion battery fires and had seen "non-manufacture changes" to batteries in several of them. Fire and Rescue NSW data presented to the inquest put the number of lithium-ion battery fires across NSW at roughly six a week.

What the inquest heard

The Teralba fire involved a battery that had been repaired by a backyard operator, with mismatched pins inserted into the pack and its casing pierced before it failed. Testing shown to the court found temperatures inside a failing pack can reach around 900 degrees Celsius within minutes, with individual cells ejected up to 40 metres.

The inquest is also examining three other incidents, including a food delivery rider who suffered burns to about 20 percent of his body when a second hand replacement battery exploded in his bedroom. Fire and Rescue NSW Assistant Commissioner Brendan Cox told the inquest that backyard repairers claiming to be experts had been linked to fires in both NSW and Victoria, describing the work as unregulated and dangerous.

Why it matters for e-bike owners

Genuine battery faults do happen and are covered by manufacturer recalls, but this inquest is about a different risk: batteries deliberately opened up and modified outside the factory. A cracked casing, a mismatched cell, or an aftermarket pack bolted onto an existing battery removes the safety margins the original design was tested against.

What it means for buyers: if a battery is damaged, swollen, or simply flat and old, the safe move is a manufacturer authorised replacement or repair through the dealer network, not a cheaper backyard fix. When you are comparing e-bikes on BikeFinder, check what warranty and battery support each brand offers locally in Australia, since that support is what stands between you and a workaround that ends up in a coroner's report.