'Counterfeit batteries' spark fires, alarm in power tool industry

"The battery that was charging suddenly exploded while the workers had stepped away for a break."

Last year, a fire broke out at a residential construction site in Seodaemun-gu, Seoul, while a power tool battery was being charged. The blaze started from the battery while workers were away and spread to the surrounding area, causing about 30 million won ($22,100) in property damage. After the incident, industry officials examined the battery and determined it was counterfeit. That same year, a battery in a power tool exploded at another large construction site, halting work there as well.

The power tool industry is waging war against counterfeit batteries. Fake batteries that closely mimic the appearance of genuine products are circulating online, and low-cost compatible products built to match the battery specifications of well-known brands are proliferating rapidly. Industry officials warn that using non-genuine batteries without adequate safety testing can lead not only to equipment failure but also to fires and explosions. "When we open up products brought in after a fire, a significant number turn out to have exteriors that copy the real thing but are counterfeit inside," a DeWalt official said.

Battery fires have become a serious social problem. According to data released by the Seoul Metropolitan Government's fire and disaster headquarters, based on National Fire Agency statistics, domestic lithium-ion battery fires totaled 678 cases over five years — 98 in 2020, 106 in 2021, 178 in 2022, 179 in 2023 and 117 in 2024. The Seoul Metropolitan Government advises consumers to check for KC certification and use only genuine batteries and chargers to prevent battery fires.

Power tools face a heightened fire risk because batteries are repeatedly exposed to impact and vibration during use. Genuine batteries operate with circuits linked between the tool and charger to monitor battery status and control overcurrent, overheating and overvoltage. Products that only match the external shape and terminal specifications of genuine batteries lack these communication and control functions, raising the fire risk, industry officials say.

In practice, Makita's domestic distributor warns about non-genuine compatible batteries, noting that they "may lack a built-in CPU or may not have functioning overcurrent, over-temperature or overvoltage protection." Failures caused by using counterfeit or compatible batteries and chargers void the warranty on the tool body as well. Makita's global headquarters has also repeatedly warned that using non-genuine batteries carries the risk of battery rupture, fire, and injury or property damage.

DeWalt confirmed counterfeit battery distribution in South Korea several years ago. In 2021, DeWalt Korea identified counterfeit versions of its 20V 5.0Ah DCB184 battery circulating in the market and issued a separate guide to help consumers distinguish genuine products from fakes. At the time, the company warned that using counterfeit batteries could pose serious safety risks and urged consumers to verify KC certification information and manufacturing date markings.

The problem is that counterfeits are becoming increasingly sophisticated. Fakes now replicate not only logos and product names but also battery indicator lights and various certification marks, making it difficult for ordinary consumers to judge authenticity from photos alone. Counterfeit power tool bodies copying the designs and trademarks of well-known brands are also being traded online and through overseas direct-purchase channels.

Companies are stepping up their response. Stanley Black & Decker, which distributes DeWalt and Stanley products, has dedicated staff handling counterfeit issues and uses an AI-based online monitoring system called Marc AI to keep constant watch over major open marketplaces and shopping platforms. Marc AI detects and blocks counterfeit goods and intellectual property violations online; rather than having staff manually search shopping sites, the AI scans Coupang Inc, Naver, AliExpress and other platforms to flag listings suspected of selling fakes. Suspected counterfeit products are reported to the platforms, and removal of the sales pages is requested.

Makita also works with a firm specializing in counterfeit monitoring to scan major online shopping platforms and open marketplaces, reporting and requesting the removal of listings identified as fake. Beyond online channels, the company provides guidance on distinguishing genuine from counterfeit products offline and tracks distribution routes through a genuine-product registration system.

"At large construction sites, our staff go out and collectively check whether the power tools workers bring are genuine or counterfeit," a power tool industry official said. "When we find a fake, we notify the company and advise them to replace it." The difficulty, the official added, is that sellers exploit low prices to keep relisting similar products under different seller accounts, making it nearly impossible to stop them at the source.

The power tool industry has called for mechanisms that would allow platforms to share information on sellers who repeatedly list counterfeit or uncertified hazardous products and to restrict their re-entry. For products like batteries — where a defect can lead to fires and casualties — treating the issue solely as a matter of trademark infringement and consumer harm falls short, industry officials say.

"A battery that looks the same on the outside is not the same product," one industry official said. "Consumers cannot tell from an online listing how the internal cells and protection circuits are configured. There are limits to a system where manufacturers spend all day searching for and reporting fakes. We need platforms to filter out sellers who repeatedly list problematic products."