Comment by jakeinspace
4 hours ago
A cheap diesel/gasoline generator might do like 5kW, which is enough for overnight charging but not for range extension or powering the wheels. There were several pretty good range extended EVs (plugin hybrid with larger battery and smaller engine), like the Volt and BMW i3, those had small engines that mainly acted as generators for the battery, but with enough horsepower to at least keep you rolling on the highway. A $300 modular generator ain't quite gonna cut it.
I believe there's also a bunch of Chinese vehicles with similar design, entirely electric drivetrain with gas generators for range extension. Most of these will need to kick in before the battery is empty so that there's some stored energy buffer available for acceleration.
To put it in perspective why a 5kWh generator isn't a range extender: my lightening has a range of 331 miles and 135kWh battery. If we assume a spherical cow (60mph, and I get every single one of those 331 miles), the truck buns through the battery in 5.5 hours, which equates to 24.5kWh to keep up.
In actuality, at highway speeds I'll burn through 80% of the battery in 3 hours which equals a run rate of 36kWh. If we ran a 5kWh generator the whole time and assume perfect charging efficiency, it'd extend the time to charge by 28 minutes.
My Chevrolet Bolt actually shows me the real-time kW draw from the high voltage battery and, while it's highly dependent on driving conditions, it seems to require around 12-15 kW to maintain 60 MPH on a flat dry road using cruise control and with the climate control turned off. It's not the most efficient model on the market, but it's also far from the least; as you noted your F-150 would need significantly more energy under the same conditions.
The lightning is ridiculous, it weight 70% more than your bolt and is huge.
My partner and I honestly bought it to be a whole house backup battery. My regions get ice storms and we have hundreds of gallons of aquariums we'd need to keep powered through a long duration power outage. 135 kwh of battery storage cost more than the 135kwh battery truck, so we got a whole house battery backup system with wheels and cruise control. It can backstop 80 amps for 3 days.
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For what it's worth you get fairly similar results if you assume an efficiency for a ICE engine (25-40% depending on a lot of things) and work backwards from the energy density of the fuel and the milage you achieve over a trip.
I think you mean kw. The kWh rating is basically just how big the gas tank is.
Technically correct for the rating of the generator output capacity, I was just meeting OP where they were at and they used kwh as a unit for the generator. At the end of the day, that nuance isn't all that important
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