Energy formula

[lcp1992]

Can anybody tell me which are the formulas to find energy in capacitors in series and in parallel?

 

[grzz]

Lest us start with a single capacitor.

What is the formula for its energy?

 

[N2O2]

The best way is to find the equivalent circuit and then use $\frac{1}{2}$CV²

 

[grzz]

If the capacitors are in series (resp. in parallel) then their charge (resp. voltage) is the same for each and so it would be better to use a formula having charge (resp. voltage).