The PixelWhips Rev2-4 use a 18650 Li-ion battery, 2400 mAh, that comes with a charger.  

We no longer offer batteries and separate accessories due to stock issues since early 2020.

If you just need to buy an extra battery, you can simply order one from Amazon or the Battery Store. You’ll need a "18650 Lithium-Ion, PROTECTED CIRCUIT" (button top battery) :

If you need a charger, you can buy a Nitecore UMS2 charger on our website. This 2-bay charger uses intelligent charging technology and displays battery health, charge, and charge time.

See our full online PW4 user guide.