Ryan i asked on another forum and one guy said this.

" my N95 will last a few days on one charge if I don't do much with it. If I leave it on the bookshelf I could probably get the best part of a week out of it.

And it's original battery is still going strong nearly 3 years on.

I just had a look and there are several ebay sellers with "genuine" bl5f batteries for under a fiver, if you go to a semi reputable online shop then they are around £20, with a couple of places having them a little cheaper.

Now why would that be?"

I think hes saying you probably bought a fake battery hence why it was so cheap