I guess it wasn't mplayer (nor Canola and other media player apps that use it) causing the sudden dying battery after all because the other night I went to bed with the battery reporting 3 days of idle time, nothing special was running, wifi was off. And I never use USB networking. The next morning I woke up and my N810 battery was dead.
I can't remember what I did on my N810 before I want to bed. I just know that I didn't run any app that uses mplayer.
(I might have done a USB file xfer from my PC via the USB cable with the N810 acting as a removable hard disk. This is not USB networking.)
Using the 'top' command I see that after a reboot I have 5 maemo-launch processes running. Four of them are using less than 1% but one is .7% to 2.3%...not much, so they can't be the culprit.
Reboot might be a good way to elimate any dangling unneeded processes that refuse to die. I almost never reboot because the idle battery use was so low.
UPDATE: After a reboot and 24+ hours I can safely say my battery life appears to be back to normal. From now on if I have any degraded battery performance events I will do a reboot and see if that solves the problem. Normally my tablet is on 24/7 and never is rebooted.
Just wanted to report that since I've used UISB control to change the USB status to "peripheral" myh battery life has increased by leaps and bounds. It's almost like when it was fresh out the box. I think previously I was leaving it is peripheral mode. Seems this was sucking juice all day.
