N8 Sudden Decrease In Battery Life

Question

I have had my N8 for years and have loved it every minute.  Through ^3, Anna, and Belle i've always had 2 days of battery life with average use (power saving off).  Last week however, my N8 suddenly had battery issues.  There were no app, firmware, or setting changes preceding.  So it's not anything obvious draining it.
When I charged the phone overnight (wall charger), I'd wake up in the morning and see Nokia Battery Monitor showing that the phone stopped charging prior to 100%. For example it would state: "Charged xHr yMins ago to 95%" or "98%".  Occasionally it would also show up at 100%.  
With this also came a drastic sudden drop in battery life.  I would see approximatley 14-15h of life, and now I'm down to about 9-10.  When looking at NBM stats, it would say "Background" used >100% of battery life at times.  Under background would be things like Messaging, Music Player, and Notes, which is completely wrong.  See below:
Here's what ive tried so far:
1) Use AppStop to kill all background apps, no effect.
2) 7370 hard reset to clear everything and go to factory settings.  Wiped phone, mass, and card. No effect.  Used AppStop to get to bare minimums.  No effect.
3) Reinstalled Belle via Suite.  No effect.
4) Let battery drain until it shut off, then used wall charger while phone stayed off overnight. Nope
5) Let battery drain down til shut off, then used USB charging. Nothing. Repeated this hoping it would "recalibrate" battery levels.  Nothing.
Nokia Energy Profiler Stats:
Ran this for about 20 mins to get some stats:
1) Idle draw with screen on is about 0.20-0.30W, 15% CPU consumption.  Occasional spike up to 30%.
2) Idle with screen off is barely 0.02W, 3-4% CPU consuption.  Occasional spike.
3) Based on the power consumption, it still estimates that I should get 40+ hours of battery life on a full charge.
Battery lasting less than a day?  I feel like an iPhone user.  I get that I could always turn 3G off or power saving on and stretch it a bit more, but that's not a fix, it's just a Band-Aid over a bigger issue.   Anybody have ideas?  Should I buy a new battery and replace it?  

Answer 1

Updates:  So I bought a brand new genuine BL-4D hoping it would fix the problem.  Nope, didn't happen...though the battery seems to now charge to 100%.   EIther way this leads me to believe it's not  a battery problem.  Unless there's an issue with the charging circuit, this I"m back to a consumption problem.
So I tried another belle refresh and a "Factory Settings" restore from the menu, didn't help.  Not sure what to do now, as Battery Monitor doesn't really point me to anything that's killing the battery.  So I decided to do more research with Energy Profiler and ran it for approx. 50 mins to see what the consumption deal is.
I exported the data as a .csv and cleaned up the data.  I've attached the power and current graphs.  In both graphs you see that there's very low consumption immediately after starting the measurement and locking the phone.  Afterwards, there are two distinct idle consumption values, approx 42mA (.16W) and 130mA (.49W).  
An average 42mA power draw would give me approx 28.5h battery life (1200mAh/42mA=28.57h).  However an average power draw of 130mA would result in a 9.2h battery life.  The actual average of all my Current data points is approx 99.9mA, giving me 12h of battery life, which is about what I'm seeing at the moment.  
I know my idle consumption is lower with 3G off and even lower with power saving on, but I haven't gotten the chance to record these measurements yet.
I'm still not sure what's causing a high idle power consumption, any ideas?
Attachments:
11-7 Current.jpg ‏64 KB
11-7 Power.jpg ‏62 KB