Charging E Vehicles

With the impending advent of an electric fleet there is one major issue. Charging vehicles. 

The current set up is flawed. The time it takes to charge a vehicle. If a car runs for 4 hours to drain power, it stands to reason it takes 4 hours to fully charge. I have a solution. 

We have several outlets that swap 9kg LPG Gas bottles where outlets have fully charged gas bottles and you get a charged one swapped with your empty one.. 

So why not do the same with E Charging. All E cars etc have the same standard battery suite where you pull into a E Charging outlet, hand over the dead batteries and swap in new fully charged batteries. The charging outlets also monitor the batteries for any issues. Stands to reason there will be no charging wait time.