[Ecky]

For those not familiar with this technology, Mazda kindof hybridized the Mazda 3 and 6 back in 2014. Those cars have a variable voltage alternator (up to 25v), a supercapacitor bank, a DC-DC converter, and a special battery which I'm going to guess charges more efficiently. With these parts, Mazda was able to have a very basic regenerating braking system.

Best info I've been able to find claims the caps can hold 25kj. Someone check my math, but I estimate a 3000F 2.7v capacitor holds about 30k joules. Adding more caps in series increases their voltage while reducing capacitance, so chances are good these caps are effectively 10x 2.7v 3000F caps in series.

Thinking about it today, I'm sure there are tons of 3's and 6's in junkyards. I wouldn't know what to do with the alternator, but this might be a cheap source of capacitors. Shipping them is likely not an option as Mazda claims they may leak if turned upside down.

Anyone want to raid a junkyard and find out?