I recently ordered on eBay 100 energizer AA batteries.

I tested them using a simple battery tester from radio shack. 4 were dead,
one was near death, and 95 were at an identical high mark, but just a
"little" below an energizer I bought from a retail package from Home Depot.
The tester is simple and unmetered, save for a "75%" mark. The needle moves
up to almost the same spot as my control (retail) battery does.

They were shipped in 2 corrugated cardboard boxes, roughly the height of an
AA cell. 50 in each, all standing up on the negative (flat) end. So
(especially if they are stacked) the top and bottom of all the batteries are
touching the top and bottom of the cardboard box. HUGE speculation: If the
cardboard is even minutely conductive (humidity, acidity, or whatever) then
I have effectively a wired in parallel 1.5V "50xAA-amp" "battery" that is
shorting through its own packaging (?)

Is there another possibility for this, other than just lesser quality
batteries? And is the cardboard shorting even possible? I'm working with
the seller to try to figure this one out. He's asking about possibly
putting a plastic or foam sheet above or below them. I'd appreciate your
thoughts on all of this.