I just did this after posting that. And yes my phone reported warnings @ 25% 15 10 5 and then shutdown @ 1%.
This way is like reconditioning an old rechargeable ni-cad batt.
All this does is completey drain batt then, with least amount of drainage (phone on, apps& radios running) allows battery to full charge.
There is also a way called recalibrate battery. But this way over charges the batt.
EDIT: I think the phone load will effect reported batt left. I think batt gage use average loads to estimate remaining power. Meaning games, full brightness of LCD, radios -3g -GPS -WiFi -Bluetooth will use more than avg power
edit 2: I found this thread also has some very good points and links. after reading this i will not intentionally take my batt to 0%. I hit 0% about 1-2 times a month on accident as it is. i will just make sure when i do go 0% to wipe stats (dont know if it helps or not) then preform a long (overnight) full charge with phone off.
http://xdaforums.com/showthread.php?t=1445698
SORRY for ranting on about this, i thought i was smart but i am still/always learning.
From my XPERIA X10S v8.2 on kCernel @ 1.19ghz