tony sayer wrote:

I've been on a 120 mile round trip today I might end up doing that
again or more next week. I might not go anywhere the week after ...

Batteries can get 200-300 mile - RIGHT NOW. Then use light composite
materials for the body, as the Russians are right now.

Then there is the "range extender"

Right so what power can that store then compared to a conventional
battery and if so is it cost effective for a motor vehicle application
giving say a "useful" capacity and range?. I'd like a range of say 400
odd miles on a tankful or charge...

The average car driver DOES NOT need a range of 400 mile in 95% of use.
Hence why range extenders will be introduced. Many small cars will be just
EV.

The secret is brake regen and supercapacitors/efficient batteries.
The new Russian hybrid using the rotary vane engines range extender
uses supercapacitors.

Well if your going to add in another engine why bother with all the
electric traction?..

You really do not get it.

Look at the links I gave for the Russian Rotary Vane engine.