Zumo 550 replacement battery?

I'm thinking that maybe my Zimo 550 needs a replacement battery. I'm not finding a battery on the Internet to the specifications of my unit's battery. 4.2 volts and 2000 mAH ratings. I have even put in the part number on line and batteries with less ratings pop up.
I have an info request in to Garmin about this.

Has anyone had to replace their battery? Did you get the correct rated battery? I so, where?

Thanks!

I would send the Zumo 550 for repair ($45 or $55). Usually they send you back a new or refurbished one. Done that.

The Garmin web site identifies it as a 3.7 v battery and directs you to Radio Shack. This link from Radio Shack states that it is the correct replacement for the ZUMO 550: http://www.radioshack.com/product/in...ductId=3393819