Interesting observation today; I set up a series stack of 4 cheap electrolytic capacitors (10V 220u) and after about 5 mins of applying 30V the lower most cap had settled at -300mV. The other three were at different positive voltages with the sum total being 30V.
Can anyone please explain why this cap went negative? I understand that different capacitances will lead to different equilibrium voltages but not why one would go negative.
Thanks in advance.