Hoverboards aren’t just for Christmas: Why self-balancing scooters keep exploding

Despite being illegal to use on roads and pavements in the UK, self-balancing “hoverboard” scooters are growing increasingly popular both in Europe and the US. Although mostly looked at as a toy and a fad that will fade soon, the scooters could be more dangerous than they seem, but also represent a wider issue in the hardware industry.

Over the past few months, dozens if not hundreds reports have surfaced of hoverboards catching on fire while charging or being ridden, causing damage to property and injuries to the owners. In Kent, a family suffered £25,000 of damage to their house after a self-balancing scooter exploded in the kitchen.

In October, London Fire Brigade issued a safety warning for hoverboard owners to “keep an eye on their new gadget whilst it is charging.” The Fire Brigade said they had been “called to two fires in two weeks involving personal transporters that were on charge.”

Similar reports have surfaced in the US, where self-balancing scooters are not only as popular as in the UK but also can be legally ridden on the streets in some states.

What went wrong

As noted in many reports, the part of the scooter that explodes or catches fire most often is the lithium-ion battery that’s usually installed under one of the footrests. As the self-balancing boards gain momentum on the market, a number of manufacturers seem to be cutting corners by using low-quality batteries to bring the price down.

“There are a lot of factories in China that now make Li-ion batteries, and the reality is that the quality and consistency of these batteries is typically not as good as what is found in top tier producers such as LG or Samsung,” Jay Whitacre, Professor of Materials Science & Engineering at Carnegie Mellon University, told Wired. “These are known as ‘low cost Li-ion batteries’ by most in the industry—they are not knockoffs or copies, but are instead just mass-manufactured cells.”

Later on, he explained that in most cases the problematic part of the battery is the separator between its anode and cathode, which may not be aligned correctly. That, as well as possible metal impurities in the separator, can cause a short circuit, which inevitably leads to a fire.

In order to understand the market situation around hoverboards it’s useful to take a look back at the history of the device. In 2014 a patent for a “two-wheeled, self-balancing vehicle controlled using foot-motions over a connecting board” was granted to Shane Chen, an engineer from Seattle. In 2015, Chen sued Chinese-based CHIC and US-based IO Hawk, a manufacturer and distributor of very similar devices, respectively. Later on, however, he was sued himself by Ninebot, the company that acquired the Segway and now claims to be holding patents for all self-balancing vehicles in the US.

For hundreds of entrepreneurially-spirited individuals, this legal standoff meant that the market for self-balancing scooters had suddenly become wide open for everyone.

Chinese manufacturers understood the situation very quickly and started offering white-label hoverboards made to order for as low as £100. The bottom line is, starting a business selling self-balancing scooters was (and is) as simple as ordering a bunch of them on Alibaba and putting your logo on them.

Predictably, these developments led to serious quality issues. Andrew “Bunnie” Huang, a hardware analyst based in Singapore, spoke to Quartz about the US hoverboard market. Self-balancing scooters “are sold by importers, who barely even know the factories they are buying it from,” Huang said. “In a hyper-competitive market that’s driven by a fad, taking six months to do a comprehensive testing program for safety means you’re missing out on a lot of business.”

There’s little reason to think that the situation differs significantly in the UK and the rest of Europe. Earlier this month, thousands of hoverboards were impounded at UK ports. The UK Trading Standards body examined more than 17,000 of units and concluded that some 15,000 of them failed basic safety checks.

Tighten the screws

In the UK, many retailers appear to have reacted very valiantly to these reports of unsafe scooters, removing all or most of their hoverboard listings from their websites and high-street shops.

In early December, high-street retailer Halfords issued a partial recall of its £499 Air Runner Self Balancing Boards. Devices bearing the serial numbers 190375, 192470 and 192488 were thought to have been sold with a mains plug and charger that are not compliant with British standards. The customers were prompted to return the devices to the local store for a full refund. The company identified then that 144 of potentially unsafe devices had been sold.