Don’t ask me why the Nokia N96 has a tiny 950mAh battery – the N-Series folks generally seem to enjoy making crazy decisions. Usually, third-party manufacturers step up and produce expanded batteries which either have a more effective chemistry or require a new back plate.
Nokia could do the latter themselves according to TheSymbianBlog – this particularly daring colleague of mine simply took a BL-6F battery from another phone and found out that it fits the N96.
The contacts and physical size actually fit in perfectly – the only problematic thing is the backplate, which bends out slightly when the phone is shut.
Hit the link above for a video and further info – I guess that I will be out to get such a battery shortly…