Not an expert but my understanding is that electric motors are pretty cheap. In fact, all of the key components of an EV are cheaper than ICE – except the battery and HV systems.
So it’s relatively easy to add another motor, something that’d be much harder an more expensive in an ICE.
Probably the same reasons the vast majority of electricity users decide to hook up to the grid instead of generating their own power. Or, put another way, the reasons a connected grid exists.
I’m far from an expert so it’s hard to really disprove your assumptions , but you make an awful lot of them. But I’d question costs of equipment and fuel. I’d question whether a diesel generator makes sense for a highly variable demand like DC fast charging. I’d question the emissions and efficiency. I’d question a lot.
Seems like something that can be done pretty easily within the existing charging apps. I believe ChargePoint offers it (maybe the charger owner has to opt in or something).
Sorry to pile on but charging to 100% on DCFC is far from ideal.
EQB’s charging speed drops a bit around 50% and then significantly at 85%: https://insideevs.com/news/492300/mercedes-eqv-dc-fast-charging-analysis/ So you’re wasting a lot of time to get that last little bit of charge.
You really wouldn’t add many more stops if you charged only to 80% or so. And then when you’re staying somewhere for the night – hotel, house, etc. – that’s when you go fully to 100%, because you’ve got the time and Level 2 charging (well, Level 1 too) doesn’t slow down at the top of the battery.
EQB also isn’t great at fast charging but you can make it work. I have a Kona and it’s even worse at fast charging, but it doesn’t bother me. We’ve never needed more than one DCFC per direction on a trip anyway.