Modern batteries last a lot better, and there’s a huge difference between an 80 mile EV that’s lost a third of its range and a 300 mile EV that’s lost a third of its range anyway.
Also, PHEV vehicles will retain most of the benefit of all-electric, while alleviating range anxiety stemming from deteriorated batteries
PHEVs have their own disadvantages, though.
They’re a lot more complicated with higher maintenance costs, and also often don’t have an EV drivetrain that’s fully independent. They’ll kick on the engine when accelerating, going uphill, for cabin heating, etc. Most of them don’t just use the engine as a range extender.
PHEVs only make sense so long as batteries continue to be expensive. The complexity of manufacturing the dual drivetrain and plummeting battery prices is going to see PHEVs become more expensive than gas cars or long range battery EVs in another year or two.
Those are all serious concerns, and I expect PHEV vehicle design to change over the next few years (my only concern is how many “few” is).
The more sensible design if you’re are going for ‘ICE as backup’, not ‘electric as efficiency improvement on top of ICE’ is a typical electric ‘drivetrain’ and battery, with a generator, more similar to diesel-electric trains. A switch to diesel in general wouldn’t be a bad idea either, but the north american market would be resistant.
Depending on how gas prices and the EV market go, I wouldn’t be surprised if drop-in engine replacements for converting ICE vehicles to hybrid become easily available in the next 5-10 years either, especially on larger vehicles.
It’ll still be a typical ICE transmission, which will still be less efficient, but you can run the engine at the ideal RPM all the time which helps make up for that. Where to put enough battery to be worthwhile is problematic, but the vehicles that would benefit most tend to have vestigial truck beds, so there is that
