Replacement battery for Archos MP3 player

I have an old archos Gmini XS100 MP3 player which i need a new battery for. Problem is i dont know what type it is exactly but if someone could point me in the direction of places which sell something of similar specs.

What i do know is this
Lithium Ion
3.6v-4v

40mm Long
10mm thick
25mm high

Heres some pictures



Thanks for taking the time to read my post.

The basic approach I can think of is visit dealextreme.com and look at the cellular phone batteries. A lot of them specify dimensions, though you may have to scroll all over the page to find them. Find one that's the right size, and be ready to solder wires onto it since the connectors are likely to be in the wrong place. Or if you want to be upscale, figure out which expensive OEM battery the DX battery replaces, then go to a phone store and buy the expensive battery. In my experience the DX batteries don't work as well as the originals, but they are usable, and cost way way less.

I will try doing that. :thanks: