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 )

First weld testing

First weld testing
crude but it works

I rigged up some welding electrodes from copper bar and rod,made a fire button to manually turn on the big SCR,found some thin stainless sheet metal about the same thickness as the battery cases.

The first welds were not strong enough,and could be twisted off with only a tiny weld zone that was not sufficient, so I got some 1/4" X 1" copper bar to lower the resistance to the work and between the capacitors, dug out some more capacitors, and made a new capacitor bank.
The new cap bank totaled 790,000Uf and can be charged to 25V, yielding 247 Joules or Watt seconds. The weld penetration looks complete across the electrode tip width, and is slightly burned, so we have more energy concentration than required, so a lower voltage or wider tip may work even better.
The welds are quite strong, so we may have sufficient energy for welding the cells, but a bit more Capacitor, maybe a total of 1 Farad or so would be better.
This would allow operation at lower voltages and will leave the base metal in better shape.
Will put out some feelers to see if I can scrounge up some bigger Caps.
Next I need to make the cell holding and weld electrode assembly and try welding real cells.