Capacitors self charging?

Breining, Jim C ( )
Mon, 11 May 1998 23:51:32 -0400

I have a small bank of capacitors ( 8 3300mf 25v in parallel ) that I was
testing in a circuit. After shorting them to discharge when I was done, I
checked the voltage and got a reading of not zero, but 16.5 mV. I took
another reading a couple of hours later, and it was up to 25.5 mV. This was
Saturday 5/9. I took another reading just now (Monday 5/11 11:00 PM) and
they were up to 81.5 mV. Readings were done with a Fluke 77 on the
300 mV scale. No equipment has been operating or even plugged in since
Saturday when I took the first reading, and the caps have not been
touched since except to take a voltage reading. This is all in my basement
work room which is kept locked.
I remember seeing something on Keelynet about dropping a cap or spinning one
and measuring a voltage increase but not stationary.

Any thoughts?