Newsgroups: sci.electronics
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From: stephen@dogmatix.inmos.co.uk (Stephen Collyer)
Subject: Re: Lead Acid batteries & Concrete?
Message-ID: <1993Apr23.115031.6151@titan.inmos.co.uk>
Sender: stephen@dogmatix (Stephen Collyer)
Organization: INMOS Limited, Bristol, UK
References: <1993Apr21.204556.21262@cronkite.ocis.temple.edu> <1993Apr22.220549.26828@dmu.ac.uk>
Date: Fri, 23 Apr 1993 11:50:31 GMT
Lines: 40

In article <1993Apr22.220549.26828@dmu.ac.uk>, cph@dmu.ac.uk (Chris Hand) writes:
|> Carter Ames (camter28@astro.ocis.temple.edu) wrote:
|> :   Why does a lead acid battery discharge and become dead (totally unuseable)
|> : when stored on a concrete floor?  

I think it's because the lead gets coated with lead oxide if the battery is
not being charged or discharged. I remember some advice from an ancient car
manual guide my father had, which was to use car batteries to power a garage
clock or something similar when they're not in a car. This is supposed to 
prevent the oxidation but I've no idea if it really works. The concrete floor
connection is a red herring.

|> 
|> It could be that you stored it somewhere that it could become covered
|> by moisture or damp air, which would short out the terminals.

This may contribute to discharging but would be reversible.
 
|> 
|> The same thing happens to my car (Citroen 2CV) -- damp gets under the
|> bonnet (US: "hood") and shorts the spark-plugs to earth so it won't start.
|> 
|> The solution (for the car) is to clean the plug leads and spray with
|> WD-40 (moisture repellant).  If damp *is* the problem, then storing the 

Well, this is off-topic, but back in the days when I used to drive bangers
I never found WD-40 to do anything that wiping with a dry cloth did'nt do.
I think the effectiveness of WD-40 is a myth invented by the guy who owns
the company.

|> battery off the ground may help.  I'm not sure if spraying with WD-40
|> would be safe since it is very flammable (high percentage petroleum).
|> 
|> Just a thought...
|> 
|> Chris
|> 
|> -- 

Steve Collyer.
