Hey, it's a R6 size, isn't it? Should 2 of them easily fit in cover of similar size to Mugen Cover? Just a little thicker? Then, it would require only 100k resistor (optionally, instead of resistor, PCB scavenged from any random BL5J - if someone care for circuit protection), and it would work in N900 flawlessly. Are 3000 mAh single cells really available, or capacity is faked? /Estel