"JR North" wrote: (clip) A battery will only discharge into a concrete
floor if the floor is damp, and the battery has a conductive scum of
electrolyte on the case.
^^^^^^^^^^^^^^^^^
If a battery has a conductive scum on the case, a small current can flow
from the positive post to the negative, eventually discharging the battery.
A concrete floor, or even a copper floor would not make any difference.