Moore Seat Heat has the perfect solution for you, a heated seat kit for the rzr 800, 900, 1k and generals
This kit will work with all RZR, RS1, and Generals
The kit includes waterproof carbon fiber inserts for the butt and back pad, full wiring harness with quick disconnects for easy seat removal, hi/low/off switches, relays, main fuses, and full detailed picture instructions on how to install the pads into your rzr seat.
I have all 4 seats heated in mine still with the factory battery, i also have a sound system, rock lights, 2 light bars, etc etc and the battery doesn't have any issues at all.
Install is a breeze with the included RZR specific detailed picture instructions, install time takes 1-2.5hrs, All you need is your torx bit that came with your RZR, a flat head, Pliers, and a staple gun. There is absolutely no cutting or stitching required
On the wiring side you just need to wire a 12v and ground and mount your switches in the desired place and the rest is plug and play
This kit includes everything needed to heat 1 seat (back and bottom)