[damselfly]

I have an HNC in electronic engineering, but that was attained many years ago so i'm a bit rusty.
This was in the basics though.
Those electrolytics (capacitors) are just for supply decoupling (directly across the battery) and serve to dump voltage when a surge is requested. They operate at DC voltage and aren't subject to any frequencies. Basically they're there for stability.
Any value of the same microfarad or above if possible will perform the same or better.

PS- The main purpose of a capacitor is to store charge. They are used to pass AC and block DC, and are regularly used in filtering circuits, ETC. ETC.