I remember users getting the 1500 mAh battery from the N95 8gb in the N95-1 by grinding away some of the housing around the intrusive camera portion of the chassis. So evidently the N95-1/N900 battery should be able to be upgraded to the N97/E71 battery as long as it will fit. Alterations may be necessary, though. The good news is if it is, we can upgrade those N900 batteries with the Mugen 1800 mAh battery for some improved power specs.