TheBeastie said:
When I try to evaluate dubious battery backs especially Zippy packs I prefer to go by weight then their stated Ah, going by weight that pack does seem like a somewhat real deal as its 2.5kilos in weight! Thats a chunky battery!
That's a bad way of figuring energy density, because it varies widely across batteries.
Let's do some math for that pack.
22ah x 3.8v nominal x 6 cells = 501.6 watt hours.
501.6 watt hours / 2.518kg = 199 whrs/kg.
If that pack really has that capacity, that's right up there with high end panasonic 18650's, in terms of energy density per weight. But this is some random brand - they could easily be bullshitting us.
Typical 20C lipo, by those same calculations, is 149whrs/kg. Lead acid batteries are something stupid like 33whrs/kg.