Re: (ET) Battery Care etc.

["David Roden (Akron OH USA)" <roden ald net>]

On 22 May 2001, at 10:00, Wayne Mosher wrote:

> Is it possible at all that having a grid of mild steel reinforcing wires
> embedded as little as a fraction of an inch below the surface of concrete
> would have any effect on discharge of batteries sitting on the surface of
> concrete?

I don't see how.  Concrete is still an insulator.  And any leakage 
current will be from electrolyte moisture (or possibly condensation) on 
the battery cases -- usually the tops since that presents the shortest 
and hence lowest-resistance path from terminal to terminal.

That said, I suppose that gunk accumulating on the battery top AND sides 
could cause leakage current to a metal frame or base under the battery.  
And, yes, moisture on concrete under the battery could be conductive.  
But again -- if you keep the battery top clean and dry, there should be 
no leakage path.

Hmm, I just thought of a few interesting scenarios to watch out for:

1.  A battery with side terminals ~might~ develop a leakage path across 
the bottom or sides of the case if there were enough dirt and moisture 
there.  You might not notice glop if it were on the side.

2.  With top terminals, if you wiped the top clean but left gunk between 
the terminals and the side, and the side got gloppy, I could see how the 
battery might develop a leakage path there.

3.  In the spring, when the weather changes, you might have batteries 
that had been sitting in the cold garage for months.  They have a lot of 
thermal mass, and will stay cold for a while longer -- days or weeks.  So 
suppose you get a lot of rain, and the humidity builds up.  Now you can 
have condensation on your batteries.  Presto!  A potential leakage path.  
Add some dirt and acid mist, and you could have some significant leakage 
for the time that moisture stays on the batteries.  

I do in fact run a dehumidifier in my garage ...

So I can see a few ways that batteries' leakage current might increase if 
they were stored in a garage.  But it seems to me that these scenarios 
would happen whether the batteries were stored on the concrete floor or 
elsewhere.

I guess it pays to keep the battery clean and dry on top and for the 
first couple of inches of the sides below the terminals.  And try to keep 
the humidity down.

> 
> Here is another source of info on deep discharge batteries.  I'd be glad
> to hear what our "battery gurus" think of it.
> 
> www.howstuffworks.com/framed.htm?parent=question219.htm&url=http://nyquist
> .ee.ualberta.ca/~schmaus/dcbat.html

I'll check it out.  Thanks!