As an auditor of battery manufacturers around the world, University of Maryland mechanical engineer Michael Pecht frequently finds himself touring spotless production floors. They’re akin to “the cleanest hospital that you could imagine–it’s semiconductor-type cleanliness,” he says. But he’s also seen the opposite, and plenty of it. Pecht estimates he’s audited dozens of battery factories where he found employees watering plants next to a production line or smoking cigarettes where particulates and contaminants can get into battery components and compromise their performance and safety.
Unfortunately, those kinds of scenes are just the tip of the iceberg. Pecht says he’s seen poorly assembled lithium-ion cells with little or no safety features and, worse, outright counterfeits. These phonies may be home-built or factory-built and masquerade as those from well-known global brands. They’ve been found in scooters, vape pens, e-bikes, and other devices, and have caused fires and explosions with lethal consequences.
The prevalence of fakes is on the rise, causing growing concern in the global battery market. In fact, after a rash of fires in New York City over the past few years caused by faulty batteries, including many powering e-bikes used by the city’s delivery cyclists, New York banned the sale of uncertified batteries. The city is currently setting up what will be its first e-bike battery-swapping stations as an alternative to home charging, in an effort to coax delivery riders to swap their depleted batteries for a fresh one rather than charging at home, where a bad battery could be a fire hazard.
Compared with certified batteries, whose public safety risks may be overblown, the dangers of counterfeit batteries may be underrated. “It is probably an order of magnitude worse with these counterfeits,” Pecht says.
Counterfeit Lithium-Ion Battery Risks
There are a few ways to build a counterfeit battery. Scammers often relabel old or scrap batteries built by legitimate manufacturers like LG, Panasonic, or Samsung and sell them as new. “It’s so simple to make a new label and put it on,” Pecht says. To fetch a higher price, they sometimes rebadge real batteries with labels that claim more capability than the cells actually have.
But the most prevalent fake batteries, Pecht says, are homemade creations. Counterfeiters can do this in make-shift environments because building a lithium-ion cell is fairly straightforward. With an anode, cathode, separator, electrolyte, and other electrical elements, even fly-by-night battery makers can get the cells to work.
What they don’t do is make them as safe and reliable as tested, certified batteries. Counterfeiters skimp on safety mechanisms that prevent issues that lead to fire. For example, certified batteries are built to stop thermal runaway, the chain reaction that can start because of an electrical short or mechanical damage to the battery and lead to the temperature increasing out of control.
Judy Jeevarajan, the vice president and executive director of Houston-based Electrochemical Safety Research Institute, which is part of Underwriters Laboratories (UL) Research Institutes, led a study of fake batteries in 2023. In the study, Jeevarajan and her colleagues gathered both real and fake lithium batteries from three manufacturers (whose names were withheld), and pushed them to their limits to demonstrate the differences.
One test, called a destructive physical analysis, involved dismantling small cylindrical batteries. This immediately revealed differences in quality. The legitimate, higher quality examples contained thick plastic insulators at the top and bottom of the cylinders, as well as axially and radially placed tape to hold the “jelly roll” core of the battery. But illegitimate examples had thinner insulators or none at all, and little or no safety tape.
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