Originally Posted by
LtKernelPanic
You'll be fine. Any screener who has worked the x-ray belt for more than 30 seconds should instantly know what a hard drive looks like. At worst they may swab a couple of them or do a manual bag check if they can't clearly see all of them on the x-ray then send you on your way.
This. I've seen someone pull out 3 laptops, including one very large and heavy-duty Toughbook, a few hard drives, and a bunch of other unidentifiable (to me) electronics from a pelican case at the checkpoint. I loitered a bit to see what would happen and, after swabbing everything (including his hands and shoes), he was sent on his way.
Re: the battery thing,
see here for limits/regulations.