What vehicle do you drive?

Right... when I searched Series Hybrid / EV - it all comes up with the Ramcharger, i3 etc.

AI Definition: "A series hybrid is a type of hybrid vehicle where the gasoline engine never directly powers the wheels; instead, it runs a generator to create electricity, which either charges the battery or directly powers the electric motor that drives the wheels, making it function much like an electric vehicle with a built-in range extender. The electric motor is the sole power source for propulsion, offering smooth, quiet operation, especially in city traffic, while the engine acts as an onboard power plant for longer distances. "

So... really the different between like, the i3 is... you cant plug it up? you can only just feed it gas to the generator and have a good day? Or that the range extender cannot directly power the electric motor, only charge the battery, so that is a key difference?

But the issue was the lack, or issue, of EV engine breaking? 99.9% of the time, you do not just happen upon a steep, long road down with 100% battery... you usually have to go up to go down, or go somewhere to get there from somewhere not exactly "close by"

If the series hybrid you are taking issue with is that, somewhere your going to go down a hill, and the regenerative breaking will generate, effectively more than 50% of the /real/ battery capacity - and where the "physical" breaks are wholly insufficient to do the job - and that the tech that AI mentioned "break choppers" does not exist or is not implemented directly into its created use case in this truck?

Even "where does the power go?" for the generator- AI "When nothing is plugged into a home gas generator, it doesn't produce usable electrical power because there's no current flow; the engine just overcomes internal friction and spins, consuming minimal fuel, with the energy mostly dissipating as heat and motion, like an idling car engine. The generator maintains voltage, but without a load (an appliance), no electrical energy is transferred, preventing that "wasted" power from going anywhere but being lost to heat and friction within the machine"

So... capacitors and essentially heat sinks to dissipate unused - or energy unable to be stored - into the air, as heat.

You would want a "bigger" battery than "just" what is needed to min/max locomotive the electric engine because the up/down of use, the generated power of the generator etc. so... there will be a solution to engine breaking other than explosions.

If this is a big truck or a semi- the size of an already "smaller than needed for complete EV" would not be /that much/ of a cost factor overall in consideration of everything else.

You could definitely call those vehicles a series hybrid in the sense that you have an engine in the system and it's only supplying power as a generator. The distinction I would make is in the scale of the components in the system.

Traditional hybrid: ~1-2kW battery (basically zero range as an EV)
PHEV: ~10-20kW battery (10-50 or so miles as EV only)
EV +Range extender: 50+ kWh battery (100+ miles range as EV only)

I was hoping they were designing something as a more traditional hybrid since it would be a unique application as a truck with potentially some advantages in cost.

When they design a vehicle, they have to account for the worst case applications. I was just outlining one.

You're right that it's not likely to be at 100% SoC at a peak, however, you can see how a smaller and smaller battery is going to fill up quicker from regen. It's definitely an energy management problem that would probably only crop up with a smaller battery.

The analogy of a home generator at no load doesn't really line up. Think of it more like this: you have a vehicle being accelerated by gravity. To slow that vehicle you need to dissipate that energy. Brakes are taking it and turning it into heat, engine braking you're compressing air and producing heat, or you can store that energy into a battery. In a scenario where the brakes would overheat and fade and the battery is full, you'd need somewhere else to put that energy. Braking choppers are very commonly used in diesel locomotives for this, but as I mentioned, would be novel in a passenger vehicle. Caps would work, but cost-wise, sizing up the battery probably makes more sense.

Anyway, it's all a thought exercise since they're doing the ev+range extender option. I'm sure they'll be doing more write-downs when the vehicle comes out way overpriced and doesn't sell at any appreciable volume.