Join Date:Joined: Jul 2013
No. There are a lot of cheap, generic brand ones from China, etc that have questionable specs and safety.
But brand name models should provide the correct voltage, not present a fire hazard and be of reasonable build quality. Leaving you with two variables.. battery capacity /life and price.
So I'd look for something well made - which you can infer from a brand name product or examine in detail. And then at the battery capacity and battery type. You'd want one of the better battery types e.g. Li-Ion, not lead acid, gel, nicad or niMH.