Revive Nicad Batteries by Zapping with a Welder

Step 3 Check Your Welder

Use your multimeter to make sure your welder is supplying DC and whether the gun or the clamp is positive and negative. Welders are sometimes AC and sometimes the polarity is backwards.

Turn the knobs to see what voltage range the welder puts out when no current is flowing.
This one puts out about thirty volts at the max setting.