Upgraded my lumia 920 windows8 phone software and Nokia Amber! Well the battery drains less than half a day empty! Also, the phone became a really hot hand warmer. Discharge was over 20%/hour!
Same battery drain issues happened also with the previous big system update! I attempted to put the previous experience and knowledge together and I did the following procedure.
I have had to charge my phone few times since upgrade to Amber. I let the phone fully discharge and then charged it with plug charger (fast charge) overnight to assure the 99% charge. One the charge level was down to 60-50%, charged the phone on wireless charger (slow charge) also “overnight”.
Repeated this cycle three times. Now the discharge is down to 3%-7%, depending on the data use. Of course no push messages, checked all the background task and ensured that none are working. Also, all my email accounts are either set to manual sync or every 2 hours. Screen brightness set to “medium”, disabled automatic brightness adjustment. I have also disabled glance and other new settings.
However, this sounds crazy! You have, in essence, taught the battery to be effective.
I wonder if the batteries are so-called deep cycle batteries, which should be worked until they are early drained of power and then slow-trickle charged for 12 to 24 hours. This will teach them to use all of their power before giving up. This is the best type of training you can give your battery.
Wish someone from NOKIA could illuminate this issue! Thanking ahead of their time.