I wish europeans and the west in general were more ambitious – we have become lazy….. I thought there would be shops setting to do these at affordable prices all over the shop after 10 years of EVs.

Anyways….

Nissan Leaf Battery Upgrades:

https://www.vivnevs.com/products

BMW I3 Battery Upgrades

https://www.i3upgrade.cz/en

https://insideevs.com/news/484717/upgrade-bmw-i3-battery-pack-120-ah

BMW I3 Range extender generator values are here:

https://www.mybmwi3.com/threads/rex-engine-kwh-output.315