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Jeff Liebermann Jeff Liebermann is offline
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Default Rechargeable battery question

On Mon, 16 Apr 2018 03:01:35 -0700, mike wrote:

Turns out that hobby store brass sheet can be cut into battery tabs.
It welds very easily. I wouldn't use it for anything high current tho.


You might want to try H-type nickel battery strips like this:
https://www.ebay.com/itm/183182559640
Ideally, you want mostly nickel strips, not nickel plated steel, but
I've managed to make it work. I couldn't find any H-Type pure nickel
strips on eBay.

With an ordinary strip most of the current goes through the strip,
with less current going through the stainless battery can. With an
H-type strip, the electrodes straddle the slot. This increases the
resistance of the strip as the current now needs to go around the
slot. That results in a larger portion of the current going downward
and through the battery can.

I'm not sure using brass for electrodes is a great idea. I've never
tried it. The resistivity of copper and brass a
copper 1.7*10^-8 ohm-meters
brass 8.0*10^-8 ohm-meters
making the resistance of identical wires roughly 4.7 times higher for
brass.
http://www.radio-electronics.com/info/formulae/resistance/resistivity-table.php
If you look at photos of commercial spot welder electrode tips:
https://www.google.com/search?q=spot+welder+electrode+tips&tbm=isch
methinks you'll find that most of them are copper, not brass.



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