The developer of this app doesn't have an N900 anymore, and I don't have the python skills to start making improvements.

Also, before saying there is always 5% less than reality, answer: Do you have power kernel, and if so, do you always have bq27x00_battery loaded upon boot?

Near as I can tell, there are two issues involved. One, bq27x00_battery reports a similarly named value to HAL as BME does. See this post two pages ago in this thread. http://talk.maemo.org/showpost.php?p...&postcount=603

Two, bq27x00_battery seems to fetch a slightly more accurate value than BME does. Always. I don't know why. Maybe Nokia made BME under-report in order to create an extra 'safety' layer - N900 will be recharged and/or shutdown earlier if the N900 reports a lower battery value than it actually is at. In the case of the shutdown part, this means longer before the backup reservoir of energy is wiped out. Honestly, frak if I know. What I do know is that the BME value and the bq27x00_battery percent-battery-left value is always different, with the bq27x00_battery one being higher (different use cases and circumstances can make that difference anywhere between a couple percent, to 20% under rare circumstances. I once spent an hour and a half using my N900 with the battery reporting 0%).

So, moving on: As far as I know, this means that your normal battery applet also always underreports.

What can be done about it? The way I understand, the best thing is for the applet to check if you're using bq27x00_battery. If that module is loaded, then you use the value it reports. If it's not loaded, you use the BME one like normal. I haven't checked the SVNs lately - I don't know if the developer is doing anything else with this thing right now. If I have the time, I will eventually figure out how to do it and submit the patch to him.