Not quite an urban legend.
It was true many, many, years ago when battery cases were made of porous
materials.
In this case it was possible for the battery to discharge when placed on
wet concrete.

However, it is no longer applicable to batteries made today.

Todd
'88 WEsty

David Brodbeck wrote:

>On Tue, 10 Dec 2002, Chris Smith wrote:
>
>
>
>>3) Gell-cells are the greatest invention since sliced bread.  They don't
>>spill, out-gas (noticeably) or rot your floor.  They are prone to plate
>>dammage like a wet-cell though, so never store them on a cement floor.
>>
>>
>
>Urban legend.  Storing a battery on a cement floor will not cause plate
>damage.
>
>Plate damage is caused by the battery sitting discharged for long periods
>of time.  No matter what kind of floor the battery is on, it will
>gradually self-discharge, and if you don't keep it charged the plates will
>sulfate.
>
>A cement floor does not affect the rate of discharge because the battery
>is insulated from the floor by its plastic case.
>
>             _ _
>  __ _ _   _| | |  | David M. Brodbeck (N8SRE)              Ypsilanti, MI
> / _` | | | | | |  +-----------------------------------------------------
>| (_| | |_| | | | @ cyberspace.org
> \__, |\__,_|_|_| "BSD is for people who like UNIX.  Linux is for people
> |___/             who hate Microsoft." -- Brendan Howes
>
>
>