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X-ray Scans Reveal the Hidden Risks of Cheap Batteries

Lumafield's CT scan analysis of 1,054 lithium-ion 18650 batteries found 33 cells from low-cost and counterfeit brands contained a serious manufacturing defect called negative anode overhang, which increases risks of internal short-circuiting and battery fires. All defective batteries came from the 424 units sourced from budget brands on Amazon and Temu. The defect rate reached nearly 8% among low-cost cells, climbing to 12-15% for certain counterfeit brands claiming impossible 9,900 mAh capacities. None of the batteries from Samsung, Panasonic, and other established manufacturers exhibited the defect. The low-cost batteries also displayed significantly worse edge alignment of internal wound layers. Real-world testing revealed the counterfeit cells delivered under 1,300 mAh capacity despite their inflated specifications, compared to 3,000-3,450 mAh for legitimate 18650 batteries.