The batteries are black, triangular, and have “U004 BATTERY” or “UPPBATTERY” printed on the side. They were made in China by Shenzhen Unit Pack Power Technology Co. Ltd. and sold under the brand name “Unit Pack Power” or “UPP” at online retailers, including AliExpress, Amazon, and Walmart, from 2018 through April 2024. The CPSC says that the batteries were not certified to the applicable UL safety standard by an accredited laboratory and that the manufacturer has refused to issue a recall.
“Fires from these batteries can be extremely dangerous and difficult to put out,” says Gabe Knight, a Consumer Reports policy analyst. “If you’ve bought any e-bike battery online in the last six years, check carefully to see if its label reads ‘U004’ or ‘U004-1,’ and if it does, get it out of your home and contact your local trash and recycling department for instructions on proper disposal.”
At the time of publication, the battery was still being sold on the manufacturer’s website and on Amazon, though not in all ZIP codes. (New York City requires e-mobility device batteries to conform to a tough UL standard that isn’t required in most other places in the U.S.) Amazon did not immediately respond to requests for comment on why it is continuing to sell the battery, but the seller rules published on its website show that e-mobility devices sold on the platform should conform to some UL standards.
The fire department in New York City, where lithium-ion battery fires related to e-bikes and e-scooters are a growing problem, offers electric bike safety tips. One of the main tips is to buy e-bikes and batteries that are tested for safety in accordance with UL safety standards.
An investigation by CR found that inadequately tested lithium-ion e-bike batteries were a major contributor to fire danger.
“Today’s urgent warning highlights that there aren’t any federal safety standards for e-bike batteries,” Knight says. “While some manufacturers put safety first and make sure that their batteries are safe, others don’t. That’s unacceptable and should be prohibited by law. Congress should take action now to ensure all manufacturers must meet a strong mandatory standard enforced by the Consumer Product Safety Commission.”
