If the wave of overwhelmingly negative reviews weren’t enough, it seems that Humane has discovered yet another major issue with its once-hyped AI Pin. The company is warning customers not to use the device’s charging case due to a potential “fire safety risk.”

In an email sent to AI Pin owners, the company said it had received a report of a “charging issue” that led to “a quality issue with the battery cell supplied by a third-party vendor used in your Charge Case Accessory.” Humane didn’t explicitly indicate whether the unspecified “charging issue” caused an actual fire, but it said an investigation found that “certain battery cells supplied by this vendor may pose a fire safety risk.”

While Humane is so far not using the word “recall,” the company is advising people to stop using the charging case immediately. Other charging accessories, including the battery booster and charge pad, are apparently safe as their batteries come from different suppliers. We’ve reached out to Humane for more information and whether they have plans to refund or replace the $149 accessory for people who have already bought one. In the meantime, the company is offering customers two months of its subscription service for free.

The full text of the email is below.

Out of an abundance of caution, we are reaching out today to ask that you immediately stop using and charging your Charge Case Accessory due to an issue with certain battery cells for the Charge Case Accessory.

Upon receiving a single report of a charging issue while using a third-party USB-C cable and third-party power source, we identified a quality issue with the battery cell supplied by a third-party vendor used in your Charge Case Accessory.

Our investigation determined that the battery supplier was no longer meeting our quality standards and that there is a potential that certain battery cells supplied by this vendor may pose a fire safety risk. As a result, we immediately disqualified this battery vendor while we work to identify a new vendor to avoid such issues and maintain our high quality standards.

The issue identified is isolated only to certain battery cells used in the Charge Case Accessory and is not related to the Charge Case Accessory hardware design.

Importantly, Humane’s Ai Pin, its Battery Booster(s) and Charge Pad are not affected as the disqualified vendor does not supply batteries or any other components of those Humane products, and are safe for continued use.

This article originally appeared on Engadget at https://www.engadget.com/after-its-reputation-went-up-in-flames-humane-warns-users-its-charging-case-may-too-215119193.html?src=rss