A fat Li-on battery like the Ving 850 would make sense.
That is one thing I like about the Godox flashes. (V850/V860) For the price, the battery life, and full amount of features (except the old style lock wheel :-( ), I think this should be the next build model for flashes. Options? Manual vs TTL and built in radio or not. I think Canon could sell a decent amount of manual only flashes with HSS and rear curtain sync.
7D (gripped), 70D, XSi, Canon 50mm f1.4, Canon 85mm f1.8, 18-55 kit lens, Canon 18-135 IS STM kit lens, Canon 70-300 f4-5.6 IS USM, Tamron 70-200mm f/2.8 Di VC USD, 430EX (2), 300EZ, PW Mini TT1, AC3, Flex TT5 (3)