Newbie wrapped up in wiring

[atomiclama]

as far as i understood a capacitor filled up to specified voltage and then let it out in one go

A cap will go to whatever voltage it is connected to.

If that voltage is higher than the cap is rated for, then the insulation within the cap will break down and it will go bang letting out the magic smoke.
That';s why you need a cap rated higher than the max voltage of the lipo.

[ched]

When a cap goes it';s like a little missile. Dont be anywhere near when they go.....

[hoverfly]

Reversing the polarity will also help.

[Two-Six]

Great you got it working.