Toller - The BYD battery does not have a long charge time, as when the battery is fully depleted a full charge is accomplished in 90 mins or it can be opportunity charged all day, every day with no harmful effect of the overall life of battery. The BYD battery also requires NO watering, NO equalization charges, and NO cool down after being charged. Their battery produces no heat and contains zero heavy metals or hazard chemicals, therefore making their battery (fuel) 100% safe! Because BYD is using Iron Phosphate (LiFePO4) technology in their batteries, it gives them MANY advantages over lead acid or Lithium ion batteries.
One last item to consider, what type of warranty is being offered on a brand new hydrogen fuel cell? BYD's warranty is 10 years / 20,000 hours - FULL battery replacement! I would think if the hydrogen fuel cells are as wonderful as you mentioned that they would have come with a warranty to back up their claims.