Skeleton Technologies 51V Capacitor 177F with 4mOhm ESR Rugged industrial units digikey item: 2969-SKELMOD51V-ND Purchased & used very briefly 4 years ago for reverse polarity tested on SiC inverter (400V) with 8 in parallel. Sat indoor storage since and gifted during clear out. 10 year manufacturer claimed lifespan, million cycles 4 pictured for sale on current listing. Makes for an excellent power reserve for resistive spot welding on batteries, and many other things I'm sure.
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