On 4/19/2018 9:15 AM, Jeff Liebermann wrote:
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.

Perhaps that's what I meant by line two of the quoted part...
"I wouldn't use it for anything high current tho..."
Somebody nitpicked my use of the word, "weld" with brass.
I'll rephrase...

One can use an energy pulse directed through hobby store brass
sheet cut into strips
to effect a connection to a cell very easily, but the resistance
is slightly higher precluding use in applications that require
high current, and may pose corrosion issues in unfavorable
environments, otherwise it is easy to do and works well for
many applications for those who don't have sophisticated spot
welders, a supply of the proper tab media or a desire to
'school' the poor fool who made the suggestion with links to basic
principles and value
a working battery higher than nitpicking the
suggestion that someone
use something imperfect in their eyes.
Methinks thou dost protest too much.
Brass is perfectly adequate for a metal detector.

Stated another way...If I didn't have workable alternatives,
there'd be no reason for me to post.
Scientists like perfection.
Engineers are happy when it gets the job done.