how much battery should the OS be using?

[FutureTBoltOwner]

Yes another battery thread ... I apologize but my battery has been dreadful the past two days it was doing really good the first four days but terrible today especially
So I monitored it the last two days yesterday the culprit was background apps specifically maps needless to say I killed all unnecessary ones and adjusted my sync to four hours
Today maps is still running but only at 4% which is within reason for me and I don't think there is any way to stop maps for good
But today surprisingly it is the Android OS that is the power hog normally mine ranges from 4% to 10% usage but today its been in the 19-24% range mainly at the higher end all day and my battery was already at 20% only after 3 hours and 15 minutes off charger ... So does anyone know why this spike occurred or what normal OS usage should be?
This is with moderate usage for all 6 days ive had it by the way

 

[realitydigg]

I think that the battery usage is a percentage of what has been used, so it depends on what you have done. If i take the phone off of charger and leave it alone for two days it will have cell standby at (I'll make something up) 60% and screen at 0%. So you cant really tell what is - at this moment - draining your battery. If the OS is higher today it could be because you have done less of other things (like angry birds) or less screen time etc. It doesnt necesarily mean that the OS is eating up more and more