OtterBox’s OtterSpot stackable wireless charging battery packs were released in August 2019, and now the company shared that early units may swell “under multi-stack and higher temperature conditions.” That’s a significant problem because stacking these batteries to recharge them is core to OtterBox’s pitch for the product. The company currently offers a bundle containing a 36W charging base with one battery, but the base can simultaneously charge up to two stackable batteries, plus a Qi-compatible device on top.
OtterBox spokesperson Julie Campagnoli shared with The Verge that this issue impacts units that were manufactured during the first two months of production, between July through August 2019. No injuries have been reported as of yet.
Regardless of when you may have purchased the OtterSpot, it’s a good idea to check the serial number on the bottom of each battery. OtterBox says that affected battery serial numbers begin with 229, 250, and 259.
OtterBox has kicked off a voluntary replacement program for the OtterSpot, and it will replace batteries at no cost if you call its customer service line at 1-855-688-7269. This information is located at the bottom of OtterBox’s support page, which I’ve taken a screenshot of below. The company claims that it has sent a message to customers who purchased an early unit, but I wouldn’t wait on a message if your serial number is one of those affected by this defect.