I unplugged my battery completely, and put it on my garage floor. But my voltmeter still shows +4V from my car chassis to the +ve terminal, and 3V from the -ve terminal to the car chassis. In fact it shows various voltages to random other metal objects lying around.
If I hold the battery in the air the measurements all go to 0.00 immediately. If I put it on a rubber mat I get measurements of about 0.5 - 1V. It is almost as if my battery is leaking current out the bottom of it (this would explain my car's problem with it going flat quickly).
Has anyone heard of this happening before, or is there another explanation for what's going on?
My multimeter has a new battery.