Where can i find li-poly or other batteries for scooter?

Im looking to replace my stock sla batteries with li-poly, li-ion or NImH batteries. i need 36v, and atleast 20AH. is there anywhere i can get them for a reasonable price?

There are many stores that sell only batteries. From car batteries to watch batteries and everything in between. One chain that I know of is called Batteries Plus.Type in battery stores in your serch engine and you should get a lot of results.

Ebay