You only need a battery to support you while you are off-grid. Electric trains don't run on batteries. Wireless charging is getting better. Electricity which

You only need a battery to support you while you are off-grid. Electric trains don't run on batteries. Wireless charging is getting better. Electricity which is "too cheap to meter" would mean we didn't need 'great' battery tech, current tech would be ok. The other way to solve this problem is to say "burning hydrocarbons have great energy density, and the global transport industry is already tooled up to use them, so lets use those as our 'battery' tech", and just find: - a good way to turn our global energy output into stored chemical energy in hydrocarbons - a good way to use hydrocarbons in small-scale non-transport devices (phones?)