On 16 Feb, 17:05, Alang wrote:
I know modern battery technology is supposedly different to what it
was 30 years ago but does anyone know if it is still okay to store a
dry charged car battery?

Yes, but don't put the contents back into the cells (or mix between
cells, but that's old advice anyway).

About 15 years ago, cell lifetimes improved massively when they
started to use permeable cell separator bags - a porous membrane which
avoided many of the failure modes based around a build-up of
conductive sludge around the bottom of the plates. If you mix crud
from both inside and outside the bag (still from within the same
cell), then you're losing most of the benefit.