You will have to seek out exactly the contact layout of the battery[may be moulded into the case] and the device.
A device I have that uses AAA rechargeable came supplied with part of the lower outer sleeve cut away- to allow contact with an extra contact in the device battery chamber- Additional advice in the manual advises that this is an 'Overcharge' protection device and any replacement battery should be so adapted.
Note the recent spate of Li-On battery fires in laptops- lack of overcharge protection is a likely cause
This may be of use
Good old Google- Google for more