There are two fuses: 5A and 40A, standard automotive blade-type design. It's a little tricky to get to them; the battery has a rubber plug covering each to help keep water out, but unfortunately they didn't design in a nub to grab these recessed covers with a fingernail or tool, they are recessed and flat. You have to use a small blade screwdriver, awl or (as I did, to verify the fuse size and ratings) a push-pin to grab a corner and peel them off, being careful not to damage the cover and wreck the water-resistant protection. Not nearly as slick a design as most of Rad's stuff.
Here is their instruction page for how to access and change them; I've added both to my bike's toolkit, along with a fuse puller:
Rad battery fuse replacement guide