This PowerStore Aerogel "B" series 1.0F capacitor is just just what you need to keep your circuits running during power outages and battery changes or to build a "turbo" solar engine. Rated for 2.5v it can accept surges of 3v. It comes in a relatively small 8.5mm by 13.5mm radial package and has a low ESR of 0.4 ohm.