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| Ed Boysun - 1/1/2024 15:23 The 130 Kw generator can't provide enough juice to run a 250 Kw motor continuously. What it can do is charge the 92 Kwh battery and use that to turn the motor for a while. Problem is; it will take less gas to provide the HP directly than it will to add an extra step consisting of charging a battery. Something I always hear is how a gas engine running at it's peak will be more efficient and that is true BUT. Notice that the leading experts on hybrid tech never run the gas engine for the purpose of charging the battery. They run it to propel the vehicle and usually charge the battery with regen braking or left over energy from gear reduction in the planetary. Also consider that weight costs energy to move and this pickup is likely to have a battery pack that will weigh around a thousand pounds. Speed costs range and so does weight. What the guys at Stellantis are basically proposing is a Chevy Volt platform under a pickup body. The Volt did pretty much the same thing, with an electric motor drivetrain driven by either the battery or gas generator. GM abandoned the platform and I think for a good reason.
That kinda makes sense. Trying to think through it a little. I definitely see that any hybrid is going to lose efficiency as it charges the battery and again as it discharges the battery. That happens to an EV as well. If the juice could go directly from the generation source to the electric motors without a battery in the middle, things would be more efficient.
That being said, there are also efficiency losses in drivelines. I think it's pretty common for the transmission, transfer case, driveshafts, differentials, etc to lose 15%+ of your input energy. So I guess I'm a little confused why it's more efficient to charge the battery from excessive energy that has gone into the drivetrain than it is to just charge it from the generator itself.
I have not studied other hybrids. It sounds like maybe you have. I wonder if what you're saying is that someone like Toyota focuses on not putting more energy into the drivetrain than they need to but all drivers inevitably put more energy into the drivetrain than they need to (if they didn't, no one would need brakes). So they install some sort of regenerative braking device on the vehicle to capture as much excess energy as possible and use that to charge a pretty small battery. Then the regenerative braking device doubles as a motor to assist the ICE and reduce the amount of energy the ICE has to put into the drivetrain.
I don't know if I'm saying that in a clear way but if that is what say Toyota is doing and if battery charging/depletion losses are more than driveline losses, I could see the Ramcharger version of hybrid being a less than ideal way of pursuing the concept.
Ed Boysun - 1/1/2024 15:23 As for how much HP a gas or diesel engine will need to run a 130 Kw generator, maybe ask an irrigator how big an engine it will take to replace a 175 HP electric motor running an irrigation pump.
We have some irrigation. At one point I had 5 irrigation engines and had done a fair amount of thinking on how to get at least two of them economically converted to electric. I no longer have the ICE ones (I let that ground go) but I do still have the electric ones. My experience with ICE irrigation vs electric irrigation is one reason that I really look forward to an all electric future. An ICE that runs 24/7 really shows you how much of a pain it is to maintain an engine vs maintaining an electric motor.
That being said, I think the reason people oversize ICE engines on irrigation so much is so that they don't pull the guts out of the engine. They want that engine to run a long time so they oversize it. I don't think a gearhead that drives a well needs more HP to drive it if it's an ICE engine instead of an electric engine.
In other applications with varying loads, people choose oversized ICE engines vs electric motors because if the load increases above what the ICE is rated for the ICE will fall on its face. If you increase the load beyond what an electric motor is rated for it'll keep chugging away as long as your supply wires can provide the amps and you don't approach stall torque (which is a LOT higher than the rated torque).
To me, for the situation of the Ramcharger, all that would really matter is:- Will the generator ever require more HP than the Hurricane engine can provide?
- Does the Hurricane engine sit close to the optimum point on the load vs thermal efficiency curve when it's providing power to the generator?
- Does the Hurricane engine have good thermal efficiency numbers compared to other engines?
- Will the Hurricane engine be reliable at the load levels required by the generator?
Edited by dpilot83 1/1/2024 17:17
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PHEV Pickups - Dodge Ramcharger
