-Epic takes f o r e v e r to charge.
An interesting fact since no one brought it up.
Pre battery power storage: 1150 mAh
Epic battery power storage: 1500 mAh
Naturally the Epic will take ~30% longer to charge.
But, if you look at the AC adapter output, things get more interesting.
Pre AC adapter output: 5V 1A (1000 mAh)
Epic AC adapter output: 5V 0.7A
That's another 30% less than the Pre's charging power. I'm no math wiz, but my guess is the Epic takes at least 60% longer to charge. Certainly wouldn't mind if someone w/ better understanding of this stuff explain it.
Anyway, not sure if its a dumb move that will kill my battery, but I have been using the Pre AC adapter to charge my Epic. It seems like it is charging faster. But that I really don't know until I actually run a benchmark on both. It could be that the Epic limits out how much mAh it takes in during a charge but if there is some one w/ an iPad that is brave/stupid enough to charge their Epic w/ the iPad charger (not even sure if the cable would work, but if the cable is interchangeable like the Pre or Epic AC adapter, it will), which output at 2A, that will probably charge the Epic in like an hour.
P.S. I do notice my Epic is slightly hotter when charging w/ the Pre AC adapter. But not screen ruining hot like how the Pre gets when charging and o/c'ed to 1 Ghz.