There are two separate removable, rechargeable lithium-ion batteries: one that powers the blender/USB port/lid light, and a second within the Bluetooth speaker.
The Coolest’s built-in, 20-volt ice-crushing blender will power through more than 6 gallons of blended goodness on a single charge. To recharge this battery, simply pop it out of its compartment under the left lid and slide it into the included charging dock.
The Bluetooth speaker battery is self-contained and should be good for about 8 hours per charge. This battery recharges simply by plugging it into any USB port (yes, even the Coolest's port!) using the included micro-USB cable.