This X-ray view may shed some light on Anker’s recalled power banks

Back in June, Anker recalled over 1 million of its PowerCore 10000 power banks (model A1263). Although the company didn’t go into details about what was wrong with the device, it did mention that units sold between 2016 and 2022 pose a potential fire safety risk due to an issue with the lithium-ion battery. If you’ve been wondering what the issue could’ve been, a new report from a firm specializing in X-ray CT scans aims to answer that question.

Lumafield — you may remember them as the folks who revealed how cheap vs expensive USB-C cables differ on the inside — is at it again, this time with Anker’s PowerCore 10000. The team found that they owned five of these power banks, which they labeled PB1, PB2, PB3, PB4, and PB5. After running the serial numbers against Anker’s recall form, they found that PB1, PB2, and PB3 were impacted, but not PB4 or PB5.

According to the team, they first checked the battery cells for issues by running them through a CT scan. The scan showed that these power banks carry three battery cells. It also reveals that Anker used at least two different suppliers for its battery cells. This was made evident by some cells having more vents than others and only PB3 having a mandrel (a cylindrical component that prevents core collapse).

The battery cells were ruled out as a potential cause, as they didn’t appear to have any defects like dendrites (needle-like structures of lithium metal that can form on an anode) or particle contamination. PB1 and PB2 also appear to have battery cells similar to those of PB4 and PB5. Plus, PB3 has the extra protection of the mandrel.

Next, they examined the printed circuit board (PCB) and how it’s assembled. It’s here that a potential issue is noticed. The company points out that insulated wires were used to make the positive and negative connections in PB4 and PB5. However, PB1, PB2, and PB3 used flat tab wire for the whole connection. Additionally, there’s some variation in how it’s assembled.

It appears the distance between the positive and negative bus bars is different across all three units. Lumafield suggests that the short distance and distortion to the tab wire in PB3 make it more likely to short out than the others.

The true cause of the overheating issues with certain PowerCore 10000 models is still a mystery. We won’t know the actual answer until Anker offers one. But what Lumafield found is interesting. Coincidentally, Anker just recently published a blog that details how it plans to improve battery safety going forward.