Though it is not an easy feat to find original bp4l and bp5l batts ...esp ones with a decent charge...there are a few ...mind... "a few" that do the trick....there are a couple of canadian suppliers of alt bp4l batts and one from germany for bp5l that are consistently great.

I've had my own "unique" experiences with many of the asian alts and am not interested in the variable results.
1 test with one received battery from a supplier...known or dubious is not indicative of consistency.
I wouldn't bet my time ....money...nor my 3 n810 or 3 n800 devices that are quite happy with the 5 back up batteries (a piece) AND my Solio (one of the few solar chargers and batteries that work beautifully with NIT's ...unused on ebay for $20 ...one of my best investments EVER ). Usb charge it for a trip...(charge lasts a yr. great for emergency kit) ...fully charged it'll bring a dead nokia back up full...better...hook it up during the day and run off it...by days end...it is then not running off solar but running off the stored charge...then when that runs out you still have the NIT battery to run off of....longgg run-time

http://store.solio.com/Solio-Store/C...rger-S13-AF1RW

Wish you luck though...We'll be able to pinpoint your location via the light show from the engulfing flames silhouetted on the horizon XD