CUBE is designed to accept both regular (alkaline) or rechargeable (NiMH) AAA batteries. We wanted CUBE to be as versatile as possible, especially in case of power outages, and using standard batteries easily found almost anywhere ensures that you’re always good to go.
You can use standard rechargeable advanced AAA batteries, such as eneloop, and swap them for new ones if they should ever lose their capacity, something which devices with built-in USB rechargeable batteries cannot (they end up in the landfill instead – not cool!).
Using rechargeables makes running the CUBE extremely cost-effective, especially for a daily-use scenario, while still giving you peace of mind of being able to use normal batteries if the situation requires it.
A variety of great and affordable rechargeable AAA batteries as well as chargers (from regular, solar to USB-powered) can be found at amazon. Please make sure any batteries you use are recycled properly at the end of their life-cycle.