Expensive batteries.
Ditto. One of my on-going projects is converting an old trolley to electrically propelled - 10HP and parade-slow vehicle anyway. So I called up this battery outfit in Utah : how much for lithium-ion batteries. Oh, about $60,000 he said. eeeyeah, rrrright.
We have heard though about a company developing lead-foam plates vs flat plates : far greater surface areas for anode/cathode reactions, thus greater energy density. How are they coming along? Then there’s blacklightpower.com