This. I would love such option and charge only to 80% during casual usage, switching to 100% before traveling/etc. It can really improve battery life, reportedly (at least they're doing it in industry, where saving LiIon's from wear is more important than max capacity - like, in trains) BME replacement doesn't offer it yet, but it should be quite trivial for Pali to code, if only people express interest (he become quite used to fact that I'm the pesky one pushing some crazy ideas - like, optional gconf settings, that allows repl battery meter to get real values reported by chip, instead of outright lying, when battery is not calibrated - so I would be glad if it wouldn't be only me suggesting, this time ).

I really doubt that- with current technology adapted at factories level - you can put more than 1500 Q10 (measured when discharging with 1/10C current, 150 mA in this case) capacity -which translates to max ~1700 mAh relative capacity during normal N900 usage - into BL-5J form factor. Heck, even this require a little "abusing" of said form (making it thicker than usual).

That aside, I really distrust batteries that claim unrealistic values on cover. If you're outright lying, anyway, why to put best available cells inside? If you declare 2600 mAh, you can make even more money when using 800 mAh cells there, customer is still rip-off the same as in using 1500 mAh ones.

Also, historically, the best batteries (Scud and Polarcell) were always declaring real/rounded DOWN capacity.

/Estel