# Connecting electrolytic capacitors in series to increase maximum voltage

I need to use a capacitor in a DC circuit where it would store somewhat higher voltage (hundreds of volts). The cheapest way to do that (in my case) is to connect multiple electrolytic capacitors in series, because their maximum voltage is lower than the voltage I want to store. In theory, it should work well with non-polarized capacitors. I am not sure what would happen if the output gets shorted (by accident – broken off wire etc.). I think that some of them will discharge first because of manufacturing differences and they will be discharged to other capacitors (that will be negatively biased now).

Could this happen with real-world capacitors? Is it sensible to connect a diode in parallel with each capacitor to protect it from being charged negatively?

• If you charge a bunch of series capacitors, and one of them shorts out, how would any remaining capacior become reverse biased? Or do you mean if the output is shorted? Commented Aug 19, 2022 at 15:05
• I mean shorting the output. Commented Aug 19, 2022 at 15:18
• Does this answer your question? How do I increase the voltage limit by connecting same capacitors? Commented Aug 19, 2022 at 15:31
• It's a good question that deserves an answer, but every consumer switch-mode converter has electrolytics rated at hundreds of volts, they are very common and cheap. There shouldn't be a need to do this unless you're looking at thousands of volts or need a very specific form factor.
– pipe
Commented Aug 19, 2022 at 15:38
• Don’t! Calculate the maximum difference in leakage current for steady state and max capacitance difference for max current and the voltage difference will be substantial. Commented Aug 19, 2022 at 16:56