I've built a model rocket launcher with 6 of these 630 farad capacitors wired in series. They are only rated at 2.5v so the series string is necessary to get the voltage I need. Capacity of the string is 105 farads at 15V although long-term voltage rating is more realistically about 12V. They are used because they are useful for launching cluster rockets where each ignitor may pull close to 40A albeit only for milliseconds. I charge them by plugging into my vehicle's 12V system and keep the topped up at the launch site with a 45W solar panel. Much lighter than hauling around a big-ass lead-acid battery. They work well. The largest cluster I've launched used 9 motors (and ignitors). Ignition was nearly instant as it would be when using a medium-large lead-acid battery. I calculate I could launch a cluster > 20 with similar performance. It would just take longer to top them back up.
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.
Albert Einstein
Albert Einstein