This camera is sold under several brand names: Agfa, Andoer, AbergBest, Casio Exslim, Youmeet. The battery is labeled NP-20 in the Andoer and Casio version so that should fit. It is a 3.7 Volt, 550 mAh Lithium ion battery. It is available on Amazon and eBay.
@Michael Gancott: I agree that the “Choosen Solution” (from “Mayer”) is bogus. It looks like it was written by a computer program. In fact I would bet on it. No human writes like that with stupid entries showing the identical text for “Belt” and “Drive Belt”. Then they added the painted picture of some old guy who looks like he might be experienced. Hah!! @douglasgrubbs: I don’t see where Nick said it was “brand new”. Chances are the belt is just worn so it slips when the load is put on the rotating brush. Or as Jayeff said make sure you are not using it in Floor setting when on thick carpeting.
I just bought a used Powershot A590 and it has the same low battery indication even with new batteries. I suspected a contact problem so I cleaned the contacts on top and bottom of the battery case area with a little rubbing alcohol on a Q-tip and let it dry. This seems to fix the problem, however based on what I read here I suspect the problem will recur. I like the solution with the L-shaped dental pick used to bend (pull) up the contacts SLIGHTLY and I will be doing that if the problem recurs. If you get unlucky and break off the contact you may be able to carefully fold a small square of aluminum foil and drop it into the battery hole to make contact with the remaining metal.