I updated my unlocked Lumia 830 to GDR2 as soon as it became available. Overall it's gone well with one BIG issue. My battery life has nose-dived. Overnight, my use between charges has gone from approx. 18 hours to less than 6. I've been through Battery Saver disabling anything that runs in the background but that's made almost no difference. Anyone else seeing this (I've read a similar thread in the M8 forum)? Any suggestions. Oh, and when I used Here Drive the other day, the phone lasted an hour and became ridiculously hot. Something's clearly not right.