7 days? So what? You almost do not use the phone at all.
True, everybody's usage is different at given times.
I was using another phone and I just had the chance to let an Xperia M idle for a week with only 1½ hours of light screen use.
Mail, Calendar, WhatsApp and numerous other apps were configured and active/sync'n, with background processes/services.
My main interest was to see what the telephony drain of maintaining a GSM signal with the phone's carrier over time would be.
I was happy that 97% of telephony was at the higher end of signal strength in the general area and that it only used ⅓ of the battery to maintain that signal over a week.
As a real controlled test,
GSMArena Battery test for the Xperia M is one of the better ones for comparing battery life over various phones.
Besides, having a phone last for over a week on a single charge may be mooted often, but it's nice to know it can be done in real life AND that we can say '
so what' to boot, really extolls the virtue of an Xperia M (4" WVGA screen) and it's battery life.
Pity an XPERIA S(LT26) with 720p screen can't get half the battery life of the Xperia M on a 1700mAh battery *sigh*
Oh, one thing (amongst others) I found is that Sony TV Sideview woke the system 512 times (bringing it out of deep sleep) in a week when it wasn't even used compared to mail(kaiten) which only woke the system 337 times and was used. Google Play Service (927) and Android System (742) with time held awake loosely tracking the same apps. Poorly configured apps become more noticeable over a week of almost no use.
[Update]
Model: Xperia C1905
Build: 15.4.A.1.9 (Android 4.3)
Battery: Mugen Power 1900mAh
Single Charge: 8days
WiFi: 8:30 - 23:00
Mobile Data: Off
NFC: On
Root Access: Yes
Stamina Mode: Off
Usage: No gaming, video or extended screen use. Just light use.
The above indicates that battery life has not been compromised with the fw upgrade to 15.4.A.1.9 as I note a screen time of 1h 25m on this battery cycle in the same environment.