For you EEs out there - Tantalum vs Electrolytic Capacitors
 

My C1 exploded in my megasquirt. It is a 22 uF 25V cap.

The local hobby shop didn't have a 22uF tantalum capacitor above 16V so instead I picked up some electrolytic capacitors rated at 22 uF 100V (NEV22M100DC) for about $1 total - will I be able to expect similar performance from the electrolytic caps or should I order some Tantalum caps and wait for them to get to me?

I read that tantalum caps have a better ESR and volumetric efficiency - is there a layman's explanation of these two things?

Part that exploded:
Potential replacement part: NEV22M100DC - NTE ELECTRONICS - CAPACITOR ALUM ELEC 22UF, 100V, 20%, RADIAL | Newark element14 US

yay or nay?

ESR is equivalent series resistance. The lower the value, the better the capacitor can absorb a voltage spike.

For "volumetric efficiency" in a capacitor - that just means one with a low volumetric efficiency is going to be bigger.

If it's 22uF 25V rated it might be to stabilize the load on a LDO regulator. If this is the case, you don't actually want super-low ESR (like in a ceramic cap).

Thanks guys, I ended up purchasing the 35V rated capacitor from digikey largely because 1. it is recommended by the mfg 2. electrolytic caps I bought have a rated operating life of about 1000 hours (@ average 40MPH = 40k miles) vs longer for the tantalum units.

That rated life is usually at the maximum operating temp. For some caps I was looking at, the rated life was 1000 hours at 105C. At normal operating temps, they should last a lot longer.

Thanks scenturion, i didn't know that