22µF 16v Electrolytic Capacitor

£0.26 £0.22
25uF Electrolytic, great for smoothing power spikes.

Details

Can be used as a backup timer, but be warned that the tolerance values of the electrolytic capacitors vary much more than the monolithics.

That means it can be as much as 50% lower or 100% higher than its rated capacitance!