I use 3 batteries daily. 2 Original Nokia & 1 MaxCell. I usually go through atleast 2 per day so when I get home I use the Nokia N800 and an external charger I bought from eBay. (I never used the battery that came with the external charger because I think it's 600mAh)... Also... I have fully charged all batteries in this charger and then put them in the Nokia N800 and then tried to charge them some more but they always come out with a full charge. http://cgi.ebay.ca/SIDO-Charger-Batt...QQcmdZViewItem PS: I also had to buy an extra Nokia Adapter Plug because this external charger doesn't come with one. If you don't need to charge both batteries at the same time then this is not needed though.