new hamfest finds

From: Joe R. <rigdonj_at_cfl.rr.com>
Date: Sun Jun 6 08:41:21 2004

At 12:11 PM 6/6/04 +0100, you wrote:
>On Jun 5, 21:28, William Donzelli wrote:
>
>> Most of these batteries were made in World War 2, many by a company
>called
>> Willard. They pretty much fell out of fashion roight after the war in
>new
>> designs, but probably were still produced for all of the existing
>radios
>> (mainly) that used them.
>
>Actually, small transparent lead-acid batteries (usually with the three
>balls in a column) were still made up to the 1980s. Professional
>flashguns and some "portable" phones used them.

   I just looked at my battery aggain and sure enough it has the three
columns in the back of it with the balls inside. I didn't notice that
before. I don't think I've ever seen a battery with them built in. Usually
we used a Hydrometer to suck out part of the electrolyte and test it. It's
a large syringe with a clear plastic or glass tube in it and has 3, 5 or 7
balls inside the tube. The ratio of sulphuric acid to water in the
electrolyte changes depending on the state of charge of the battery. As the
acid/water ratio changes the specific gravilty of the solution also
changes. The different balls in the hydrometer have different specific
gravities so more of them will float when the charge is higher and there is
more acid in the solution. Most LA batteries sold in this country in the
past 25 years are now sealed and are SUPPOSED to be maintenance free so
very few people know how to check one any more.

   Joe
Received on Sun Jun 06 2004 - 08:41:21 BST

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