I have attached the rar of all the files.
I have taken photos of my process of making a phone battery robot friendly.
Basically you start by removing the packaging of the battery; for this particular model (nokia 9500) that involves removing the thin packaging from around the outside, this is not a necessary step but i needed access to solder, and the final battery is smaller.
Pay attention to the plus and minus markings.
Then remove the supporting plastic, being careful not to touch the wires together.
Fold the electronics down so the space isnt wasted, and cover in insulated tape.
There are 3 contacts on top of the battery, one positive, one negative, one is unused but pulled to ground (i think) Dont solder to the centre anyway.
Next you need to prepare the wires, I have included the jumper so than i can stack the batteries, to increase the voltage. Also it is an on off switch.
I initially soldered a pin to the negative terminal and the negative wire to the other half of the jumper, being careful to isolate the centre pad.
I then soldered the positive wire onto the pad, and attached the 0.1" connectors.
Finally the battery is wrapped and ready to go.
These batteries are charged from mobile phone battery chargers, for instance, the 2 i have are for charging HTC Desire batteries.
The batteries cost .99p from ebay, the parts cost a few pence. The chargers cost £3.50 ish, but its a one time investment.
It is useful to have more than one battery as it can get confusing as to which terminal is which.
It also means you can drop the voltage to 5v.
http://dl.dropbox.com/u/5224931/Li%20Ion%20Tutorial.rar