New consulting relationship with GreenTecAuto begins
What actually goes wrong with the batteries????
A look at todays Hybrid and EV battery packs
Battery packs exposed
Keeping Warm In New England
Plugging into the SUN
Making a small solar concentrator
Building MIMA and the plug in adapters
Converting a telephone truck to electric
DIY dual pulse Capacitor Discharge Spotwelder
Cell Miller mounting the components
Welding beautifully
More snubbing
Beefing up the switching board
Rebuilding the welder
Need better welds
Welder first test
Making some cells for weld testing
More parts of the process
New weld head
Spotwelding fixture #1
More energy
First weld testing
Making a spot welder??
Chevy Bolt EV joins the family
Getting in shape while making electricity
Replacing gasoline with solar electric lawn equipment
What is Genesis One?
How to stop the aging process DIY
MIMA Install Day 2005 a Big Success!
Building a hybrid car grid charger
Tapping into the Wind
Expanding MIMA with the Distribution board ( users projects )

Making a spot welder??

Making a spot welder??
gathering components

There are several types of spot welders, but the best for spot welding batteries is the Capacitive Discharge welder.
The advantages are repeatable energy delivery,and minimum heat effected zone.
A nice production unit is about $6-12K with the weld head.
Since I don't have that kind of money, I have to try building my own.
I did some scrounging in my extensive junk pile, and came up with some possible components.
I found 700,000 Uf of 15V or better capacitors. I mounted them so the lead length would be as short as possible, but did not have the 1"X 1/4" copper bus bars that I would have preferred to use, but the 1/2" X 1/4 that I had should be good enough for the prototype testing.
I got the huge hockey puck SCR to work, and found that it is one of the rare GTO or Gate turnoff types, which means I could pulse the discharge without totally discharging the caps like a regular SCR would.
I spoke with PowerX, but they could not find the part number so I really don't know much about the device except that it is huge, and that it worked when I tested it by firing a smaller cap into a resistor.
I also dug up a small spot welding head.
Not the components I would have bought for the machine, but hopefully it will be close enough to see some welds and get a starting point.
The buss bars are too small, The caps are not big enough, and the weld head is kinda small