X-ray scans reveal the hidden risks of cheap batteries

Summary

Lumafield has released the results of a new study of lithium-ion batteries that “reveals an enormous gap in quality between brand-name batteries and low-cost cells” that are readily available through online stores including Amazon and Temu. The company used its computed tomography (CT) scanners, capable of peering inside objects in 3D using X-rays, to analyze over 1,000 lithium-ion batteries. It found dangerous manufacturing defects in low-cost and counterfeit batteries that could potentially lead to fires and explosions.The study tested 18650 lithium-ion battery cells, which are used in various products including electric toothbrushes, power tools, e-bikes, power banks, and even electric cars. The batteries were purchased from ten different brands: three OEMs, including Samsung and Panasonic, sourced from “highly reviewed, specialized suppliers,” three vendors selling rewraps (typically OEM batteries with their plastic outer wrapping replaced) sourced from “specialized battery sites” or the brand’s own web stores, and four companies selling low-cost or counterfeit batteries sourced from “large, general online retailers such as Temu.”Lumafield scanned 1,054 batteries – around 100 from each brand – and found 33 of them had a serious manufacturing defect known as negative anode overhang. The defect “significantly increases the risk of internal short-circuiting and battery fires” and can reduce the overall life of the battery,” according to Lumafield. All 33 of the batteries with the defects came from the 424 sold by low-cost brands or brands selling counterfeits. One of the counterfeits was identified by its pink wrapper designed to match the one Samsung uses on its 30Q cells. Other low-cost brands claimed capacities of 9,900 mAh while brand-name 18650 batteries have capacities in the range of 3,000-3,450 mAh. Not only were the counterfeits’ specs overinflated, but in real-world testing Lumafield found their capacities were less than 1,300 mAh.When taking only low-cos...