What's different from bi-polar and non-polar caps?

[Matt Syson]

Hi
Bipolar caps can cope with the rated DC either way around without degradation unlike 'ordinary' electros that will die if powered backwards.
Lead length is probably because the machine that makes them is the same line as the polarised one or it may possibly indicate which foil is on the outside.
Matt S

[ulysses]

As far as I know, bipolar and non-polar are the same thing. Inside, they are actually just two polarized capacitances in series, with opposing polarity.