thats an interesting video, they are Maxwell 2600f 2.5 volt caps but good luck getting them for $6
In his web page the author says that he got them at a clearance sale from Electronics Goldmine
So he has 1/2 C V^2 Joules in them. 0.5 x 433 x 144=31200 Joules. A car battery of 100Ah (not unreasonable) holds 12*100*3600=4320000 Joules. Or 138 x more energy
Easy starting car.Also explains the quick charging of the pack.
I was amazed how small the batteries in US cars are these days.
Does he say how many Farads he has ?
3000 farads each according to the author's blog