Being familiar with smartphone battery I really don't see why you can't use a 3250 mAh battery, it shouldn't cause more heat but really only increase run times. The only concern would be running the unit for hours and hours without a break which could cause heating problems.
Some of my .m4a tracks cannot be played.
The track is running, but there's no sound coming out. When I skip tracks, (those that are playable) the same thing happens. Need a restart to rectify it.
Long scanning time, w/o indication of progress.
Does this mean that it can't play ALAC files reliably after all? If that is the case, I will probably be returning mine...