Back in 2006, I bought a very nice mp3 player, which main feature is to also play ogg files (its references are LG MF-FW505, hello google). I was very happy with it, but with the age, the battery autonomy decreased to the point where it became unusable. I guess I should have trashed it since a while, but I have a big house so I didn't. And recently, I found it again and decided to use it to play the physical hacker with sebian. Disclamer: I am an absolute lamer in electronic, and I do that for fun mainly. But hey, we got some nice pictures!
The good news is that it was really easy to open. The upper face is simply glued to the rest, and there is a little space in the box to lift it up with a screwer. Once removed, it gives access to the four screw closing the box. Very nicely done, thanks to the engineers who thought about enabling us to open it up. I'm personnally bluffed by the little red V written by hand on the battery. I would have said that these things are built by machines only, with very little human intervention. I am so naive when it comes to hardware, I'm ashamed...
The bad news is that the battery is no independent component, but a little thingy in a little bag. I was kinda hopping that we'll find something with some sort of references that I could buy again and replace. In the evening, I discussed a bit on the IRC channel of the electrolab, but it wasn't really conclusive about what the next step should be. It may be a lithium-ion battery, but I think I gave them wrong informations since I didn't say that there is a little metal box within the plastic bag.
Well, we'll dive further into this with sebian after lunch, I guess. Or tomorrow since he forgot to bring his multimeter.
Note: the background paper is a document describing the Grid'5000 scientific instrument. It was written by Sebian, and I fooled him with tons of remarks and details to improve, thus the choice as background.