Hi Barney,
I'd like to give it a go:
The battery is constructed out of two sets of sandwiched plates.
One group is made out of led and and the other is made of a led based alloy.
As di-electric medium is normally used a mixture of H2SO4 (Chemical formula
for Sulfur Acid if I say the English word right) mixed with pure H2O =
water.
Now charging and decharging with this pure mixture goes with best
efficiency.
The water part vapourises in time and it needs refill now and then with pure
H2O in order to remain the battery working as new. The paltes always should
be kept under the liquid level, otherwise the dry parts will loose their
ability to work correctly even after refilling. The dry part gets an oxide
layer, which obstructs normal working order.
This will lead to a situation, that the battery cannot hold the nominal
charge anymore as specified by the manufacturer.
If however no pure water (distilled or demineralised water) is used, but
water from the tap or typical mineral water as the commonly used drinking
bottles contain (mostly) dissolved materials (minerals), the liquid mixture
between the sandwiched plates get contaminated with wrong materials.
For drinking the tap water is most times o.k. and so is of course the water
from bottles.
But think what these "mineral" materials are like:
near the coast line: often lime particals derived from the sea. These
materials pollute the narrow space between the plates, perhaps even creating
a kind of short or block current - both are wrong.
Other minerals often have metal origin - you can imagine what will cause
this:
the battery will become electrical "leaky" - i.e. it will show that the
electrical charge will fade away easily and you'll experience a flat abttery
at times you don't expect, because you did not have this happening in the
past. So you start blaming the battery, but in fact you should blame
yourselves.
I hope this kind of chemistry lesson from a Dutch guy helps.
Cheers,
Hans
doing electrical works of his '71 BGT again after a great weekend drive
----- Original Message -----
From: "Barney Gaylord" <barneymg@MGAguru.com>
To: <mgs@autox.team.net>
Sent: Tuesday, February 25, 2003 12:30 AM
Subject: Battery water
> I have a feeling this is going to start an avalanche of vaguely related
> response, and maybe even a religious war or two, but that is not my
> intention. I have only one very specific question.
>
> When discussing what type of water to use for topping off a car battery,
> the common response is usually "distilled water", and this is sometimes
> (fairly often) followed by "anything else will ruin the battery". The
> simple form of my question is, "Why?". Now before you jump into this with
> both feet, please stick to the facts and try to surpress traditional rumor
> and personal opinion (however difficult that may be), and also consider
the
> following.
>
> I have done some web searching and read what is offered by several of the
> major battery manufacturers. Some say to use distilled water, with no
> further explanation. Some say to use "good quality drinking water" with
no
> mention of distilled water, and no other explanation. At least one says
to
> use distilled water, followed by "If you don't have distilled water use
> drinking water as better than nothing", (but of course distilled water is
> also better than nothing). In most cases there is little or no
distinction
> made between distilled water or drinking water.
>
> The curious part is that in no case did I find any battery manufacture
> making any statement to the effect that any type of water (at least
> "drinking quality" water) would actually harm a battery. This strikes me
> as being quite "significant" in light of the fact that they have to cover
> warrantee returns. It seems to me that if there was any significant
chance
> that "drinking water" would harm a battery, the battery manufacturers
would
> be all over this fact and might even go so far as to viod the battery
> warrantee if you use anything other than distilled water. But as much as
I
> search I have found no such statement from any battery manufacturer.
>
> So here's the challenge, and please stick to the facts, not
> speculation. Can anyone come up with documented proof that drinking water
> might actually harm a car battery, and if so, what exactly would be the
> mode of failure of the battery as caused by the water? Best submission
> with factual proof will get a full page writeup with credit and name
> attached in the tech section of my web site (and maybe some print
> publications as well), and maybe some additional prize for furthering the
> education of mankind (but probably not the Nobel peace prize).
>
> I need real cause and effect here. A casual relationship is
> insufficient. "My battery died after adding tap water" doesn't cut
> it. Lots of batteries die (like all of them eventually) for various
> reasons. We have to know why it died, which may require an autopsy with
> photos and chemistry test results. Otherwise I would like to see some
> results of controlled parallel lab tests on batteries using distilled
water
> and "other" water. I am looking specifically for any DOCUMENTED reason
why
> "drinking water" would actually harm a car battery.
>
> Gloves off,
>
> Barney Gaylord
> 1958 MGA with an attitude
> http://MGAguru.com
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