After a whole night of flashing, updating and restoring, I think I may have figured out the issue with the falling battery capacity.
Battery capacity has been at a steady 1460mAh all day so far. Don't want to get my hopes up though - will do some further testing first.
Basically, I wanted to see if the battery bug was present on all firmwares (I have now tested 11414, 11451, 11500 and 11501).
So, I started by flashing all the way back to 11414 to do some testing. Installed the Diagnostics app and let it charge up. As expected, it would only reach ~1280mAh out of a reported 1519mAh battery capacity (however, the OS thought that it was at 100% and therefore stopped charging the battery).
I then updated it through Zune to 11451 to see if this would help. No dice. Still couldn't get it past ~1280mAh, even though max capacity was reported at 1517mAh. The OS was still reporting 100% charge too (so the extra ~150mAh was definitely not available).
Lastly, I updated to 11501 through Zune. Here's where it gets interesting. After updating, the OS reported a battery charge of 86%!! I went to the Diagnostics app, and the max capacity was now 1479mAh. Remaining charge was 1279mAh. 1279/1479 = 86%.
I tested this once again, by restoring back to 11412 through Zune, and battery was yet again reported at 100%. After updating to 11501, it was at 85%. In my opinion, this is proof that the new firmware update is 'unlocking' the remaining capacity of the battery. Unfortunately, not long after that the max capacity started to fall again
But I had another idea. Some people here have been suggesting the Diagnostics app bundled with 11501 was reporting incorrectly. So, I restored back to 11412, installed the Diagnostics app, and then updated to 11501 again. However, this time, I made sure the
keep the older version of the Diagnostics app installed on my phone.
As expected, battery capacity was reported at ~1470mAh and I was able to charge all the way up to 1470mAh.
It has been 15 hours since my last charge, and I'm at 73%. Granted, most of that has been standby time, but I have been sending and receiving texts, emails, and made a 10 minute call. Spent 5 mins on WiFi internet browsing, and ~30 minutes playing games too. The max capacity has been sitting at 1466mAh the whole day. It fluctuates, but only +/- 5 or 10mAh.
However, none of this explains why the Diagnostics app bundled with 11501 initially reports a max capacity of 1479 but then starts to fall after the first charge cycle... As I said, I'm not getting my hopes up yet - the real test will be when I do a second full charge cycle.
