The SwitchCharge is a portable, multi-functional battery case for the Nintendo Switch that promises hours of extra play time. It comes with a 10,000mAh battery, an improved kickstand, and two game card slots. It’s a great idea, which is probably why it was fully funded in under 48 hours on crowdfunding site Indiegogo. But, London-based company InDemand recently told Kotaku getting its product into backer hands has been a “fulfillment nightmare.”

Many backers are apparently still waiting for their SwitchCharges, even though InDemand said it was ready to ship in January 2018.

“All subsequent updates after that offered up more excuses for delays, as well as assurances that SwitchCharges were on the way to backers,” backer Armaan Khan told Kotaku.

Reporter Gita Jackson spoke to InDemand CEO Charlie Baron on Thursday, who called the SwitchCharge a “fulfillment nightmare” and said the company “underestimated how hard it would be to ship the products internationally.”

The reason? Lithium batteries can’t be shipped in the cargo hold of an airplane because they (rarely) can catch on fire. They have to transported in carry-on baggage only. Although there are fire safety systems in the hold of an airplane, they’re not well-equipped to deal with the kind of fire lithium batteries create.

InDemand’s slim budget isn’t helping either. The company talked about its cash problems in an April 9 update, saying it had to drip feed shipments “starting with locations with the most orders and periodically dispatching orders as money becomes available.” It also said it stopped all payroll for founders and the team since January 2018 to free up some money for backer shipments.

Baron said SwitchCharge cases are already going out to U.S. backers, while Canadian backers should expect theirs “shortly.” Shipments to Australia and Asia will happen after that.