That’s not how these systems work. The engine in the Fisher Karma only sends power into the battery.
This does make a bit more power available to the electric motor because it can now draw more amps without causing the battery voltage to drop.
Speculation Alert - possible Harvester Engine Choices
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That’s not how these systems work. The engine in the Fisher Karma only sends power into the battery.
This does make a bit more power available to the electric motor because it can now draw more amps without causing the battery voltage to drop.
Trying to read this thread is an exercise in mental masturbation with so many wild guesses/assumptions and speculation about the harvester, it’s making baby Jesus cry….
I’m disappointed in only having 150 miles on battery & how the harvester plays out will either make or break our purchasing a Scout
I’ve got a doctors appointment at the VA next week and its a 300 miles round trip round trip and I’ve never seen any charging stations at the VA hospital. Now do this in the winter at -15 with 25% less battery and the potential of closed roads………(yes I’m a broken record)!
A "hybrid" is any vehicle with more than one source of power for propulsion. Most vehicles are parallel hybrids. Some are series hybrids. If the Harvester is not mechanically connected to the drivetrain, it IS a series hybrid. This explains the difference, though still dumbed down and incomplete:
I don't know how the Harvester option will be implemented and I am not an electrical propulsion engineer but I have been daily driving a series hybrid* vehicle for 10 years. These are some modes I'd expect to see that I'm familiar with from my experience. I have a 2014 Cadillac ELR (fancy Chevy Volt) that I've owned since new. It has 4 basic modes of operation: Tour, Sport, Mountain, and Hold.
Tour - This is the "normal" mode and what the car defaults to on startup. This will use only battery power until reaching a designer specified State of Charge (SOC). Basically you are full EV until the car decides to start running the engine as needed (it turns on and off) to maintain a safe SOC for normal driving - probably 10-15%.
Sport - Claims greater throttle response, stiffer suspension, etc. I probably used this once 10 years ago, didn't really notice a difference and haven't used it since. Everything has a Sport mode though. The 2016 ELR is able to combine the generator power + battery for increased output in Sport mode which would be more useful.
Mountain - This mode raises the minimum SOC to about 30% to keep extra reserve in the battery for long uphill climbs. If you are already below the ~30%, it will run the engine continuously until SOC reaches about 30%, then revert to maintaining that SOC (engine on/off as required). It is inefficient to charge the battery via the generator so it only does it in this mode to ensure there is enough reserve for an extended high use scenario.
Hold - This is driver selectable and commands the car to maintain whatever SOC it is at when it is selected. This is basically hybrid mode and is essentially what the car goes into automatically when you reach minimum SOC in Tour or Mountain mode. This lets you keep the battery at a user selected SOC. If you select it when you start a fully charged vehicle, it will keep the battery full and start running the generator off and on as needed.
I would expect to see some version of these modes + a Towing mode that has some minimum SOC >the Mountain mode 30% as the basic drive modes.
A lot of discussion about "150 mile EV range" and what that says about the battery size. MY thoughts:
-If you're coming from a pure BEV experience, the battery in an EREV is not going to be managed the same. At least it shouldn't be.
1) There is no need to allow the battery to charge up to 100%. It's bad for the battery and you have a generator for extra range.
2) The battery will never go to 0% for the same reasons. The battery is going to be kept in a SOC range of happiness.
If the generator is undersized (as it appears to be for packaging constraints), I would expect the minimum SOC for each mode to be something higher than what my ELR uses. Maybe a min SOC of 30%, Mountain mode of 50% and tow mode 75%. Those are spitball estimates for the SOC at which the generator starts.
If the full BEV battery is 350mi, then a slightly smaller version might be say, 300mi IF it were used like a BEV battery but it WON'T be. If you only charge that "300mi" battery to 80% and only let it go down to 30%, you get...150mi of EV range. The battery acts as a buffer providing extra current when needed and storing excess current from braking or going downhill once it reaches the min SOC of whatever mode it is in.
*Yes, I know the engine/generator in the ELR/Volt is capable of driving the wheels in some situations but 99+% of the time, it is just generating electricity and mechanically separated from the drivetrain as a series hybrid.
I don't know how the Harvester option will be implemented and I am not an electrical propulsion engineer but I have been daily driving a series hybrid* vehicle for 10 years. These are some modes I'd expect to see that I'm familiar with from my experience. I have a 2014 Cadillac ELR (fancy Chevy Volt) that I've owned since new. It has 4 basic modes of operation: Tour, Sport, Mountain, and Hold.
Tour - This is the "normal" mode and what the car defaults to on startup. This will use only battery power until reaching a designer specified State of Charge (SOC). Basically you are full EV until the car decides to start running the engine as needed (it turns on and off) to maintain a safe SOC for normal driving - probably 10-15%.
Sport - Claims greater throttle response, stiffer suspension, etc. I probably used this once 10 years ago, didn't really notice a difference and haven't used it since. Everything has a Sport mode though. The 2016 ELR is able to combine the generator power + battery for increased output in Sport mode which would be more useful.
Mountain - This mode raises the minimum SOC to about 30% to keep extra reserve in the battery for long uphill climbs. If you are already below the ~30%, it will run the engine continuously until SOC reaches about 30%, then revert to maintaining that SOC (engine on/off as required). It is inefficient to charge the battery via the generator so it only does it in this mode to ensure there is enough reserve for an extended high use scenario.
Hold - This is driver selectable and commands the car to maintain whatever SOC it is at when it is selected. This is basically hybrid mode and is essentially what the car goes into automatically when you reach minimum SOC in Tour or Mountain mode. This lets you keep the battery at a user selected SOC. If you select it when you start a fully charged vehicle, it will keep the battery full and start running the generator off and on as needed.
I would expect to see some version of these modes + a Towing mode that has some minimum SOC >the Mountain mode 30% as the basic drive modes.
A lot of discussion about "150 mile EV range" and what that says about the battery size. MY thoughts:
-If you're coming from a pure BEV experience, the battery in an EREV is not going to be managed the same. At least it shouldn't be.
1) There is no need to allow the battery to charge up to 100%. It's bad for the battery and you have a generator for extra range.
2) The battery will never go to 0% for the same reasons. The battery is going to be kept in a SOC range of happiness.
If the generator is undersized (as it appears to be for packaging constraints), I would expect the minimum SOC for each mode to be something higher than what my ELR uses. Maybe a min SOC of 30%, Mountain mode of 50% and tow mode 75%. Those are spitball estimates for the SOC at which the generator starts.
If the full BEV battery is 350mi, then a slightly smaller version might be say, 300mi IF it were used like a BEV battery but it WON'T be. If you only charge that "300mi" battery to 80% and only let it go down to 30%, you get...150mi of EV range. The battery acts as a buffer providing extra current when needed and storing excess current from braking or going downhill once it reaches the min SOC of whatever mode it is in.
*Yes, I know the engine/generator in the ELR/Volt is capable of driving the wheels in some situations but 99+% of the time, it is just generating electricity and mechanically separated from the drivetrain as a series hybrid.
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Sounds like the proposed 500-mile range of the Harvester should be plenty to get you there and back, but you'll be using some gas along the way. I don't think any other 4wd EV would get you there and back in the winter without stopping for charging, assuming you have an available charging station en route. This is specifically why I like the Harvester option. Still, the implementation will be a make or break moment for me on this purchase. I don't like stopping on long trips, so Harvester output power is a critical factor in my decision and I'll just stick with ICE otherwise.
The harvester is my choice, just need to see how it plays out & the technology behind it. I’m not a fan of charging on roadtrip’s. One of my sisters lives in Calif not far from a small fruit stand tourist attraction & they have 20 Tesla chargers sitting way back out of the way. She was saying during fruit season they always have cars waiting to charge and that’s not factoring in the rolling brown outs that are always happening. This summer when we were out in Calif I counted 10 cars waiting to charge………
Whatever they use, I sure hope it is not one of the VW engines that consumes oil. My sister has a Jetta with a turbo 4 cylinder and it uses quite a bit of oil. I am told this is very common with those engines. My daughter has a hybrid Jetta with non turbo 4 cylinder and it does not consume any oil. Maybe it is the turbo oil seals or something, but let's avoid that if we can please.
The term "hybrid" has a regulatory meaning.
The Harvester option could very well require classification of the vehicle as a Hybrid.
I wonder how many pages this thread will get up to before more details emerge on the Harvester. 
Charge that battery up in like 3 minutes!Unless they can pack a GR Corolla's 3 cylinder that capable of 300hp.
...and then blow the engine, just like in the GR Corolla.
Dude, this is exactly how diesel electric locomotives work. They pull millions of pounds of cargo for hundreds of miles.
Series hybrids have been around since 1881.
How do diesel electric trains work, and why do they need turbochargers?
Why do diesel electric trains require both an engine and electric motors? And where do turbochargers fit into the equation? The answers may be surprising.
Dude, this is exactly how diesel electric locomotives work. They pull millions of pounds of cargo for hundreds of miles.
Series hybrids have been around since 1881.
How do diesel electric trains work, and why do they need turbochargers?
Why do diesel electric trains require both an engine and electric motors? And where do turbochargers fit into the equation? The answers may be surprising.accelleron-industries.com
The military is also going to EV’s powered by an engine of some kind. They have ran out of available electric power to power all needed systems & thus a diesel electric tank/apc
Don’t forget diesel electric subs and other ships that use generators to produce electricity & power the ship
Packaging and NVH concerns may require the former rather than the latter.
Electric power in to the battery does not *need* to be equal to or greater than electric power out from the battery to the wheels.
All you need is three modes:
- Pure EV mode. Sufficient for most day trips and around town driving. Harvester never turns on.
- Recharge Mode. Park, run the Harvester as a jenny, charge up and drive on. Convenient when you pull into camp for the night, or you aren't near a charger, such as at a trailhead after driving to it. Bring some Jerry cans because the next mode gets you home.
- Range Extender Mode. Harvester runs 100% duty cycle while driving. Jenny produces electricity that reduces *net* drain rate of battery. When the tank is empty and the battery is flat, you have to stop, and switch to Recharge Mode and hope you have a couple Jerry cans of fuel to get recharged again.
In all cases, the battery supplies the electricity that turns the motors.
That article says the power comes from the diesel/generator (not batteries) and powers the traction motors, which is the idea @CarTechGeek is promoting.Dude, this is exactly how diesel electric locomotives work. They pull millions of pounds of cargo for hundreds of miles.
Series hybrids have been around since 1881.
How do diesel electric trains work, and why do they need turbochargers?
Why do diesel electric trains require both an engine and electric motors? And where do turbochargers fit into the equation? The answers may be surprising.
Why invite electrical losses and battery wear by feeding power from the generator through the battery to get to the motors, instead of sending power directly to the motors, and anything not used by the motors then gets stored in the battery?
Obviously, this does not work if the current draw from the motors is higher than the generator can create, hence the request for a larger generator from a lot of us.
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Heaven only knows. Kinda wish original OP would delete it-HaHa!I wonder how many pages this thread will get up to before more details emerge on the Harvester.
No-seriously!!!
Dude, this is exactly how diesel electric locomotives work. They pull millions of pounds of cargo for hundreds of miles.
Series hybrids have been around since 1881.
How do diesel electric trains work, and why do they need turbochargers?
Why do diesel electric trains require both an engine and electric motors? And where do turbochargers fit into the equation? The answers may be surprising.
You either didn't read what you quoted from me, or the Diesel Link you provided.
Nowhere does it say the Diesel Generator in a locomotive only charges the battery. It mostly supports my point.
I'm making my last post on the topic unless someone directly quotes or otherwise asks for my input.
I don't want to harp too much on Scout Motors for using the dumbed down battery charging explanation for their range extender. It is unfortunately, a very common, but incorrect way to explain, and handwave away what is going on, while making it clear that the Gas Engine is NOT connected to the wheels. It's a simple concept and easy to understand. It's wrong, but again requires little thinking. We live in a world, where simple, but wrong, is often preferred over complicated, but correct.
What is actually happening is significantly more complicated, interesting, and versatile.
I'll credit Nissan for actually having a video by one of their Power Engineers explain how their E-Power series hybrid works, here is what the Nissan Engineer states:
He makes it crystal clear that the generator sends power to the power electronics (inverter), where it is split depending on need between driving the wheels, and charging the battery. Which is what I have been saying all along. If the Scout Engineers were free to speak, they would tell you the same thing.
Nissan Global has a handy diagram showing how it works. Note the power entering the inverter and splitting with some going to the wheels, and some going to the battery. The battery is NOT supplying the wheels at all in this case.
Believe what you want to believe, the simplified dumbed down, "only charges the batteries", or how it actually works which is more complicated and versatile.
What you believe doesn't really impact the choice of Generator engine. So we could get back to that.
Regardless of how it's hooked up, if it takes 40 KW of power to drive a 70 MPH, then a 30 KW genset is likely going to be problematic, and 50 KW genset significantly more versatile.
So the power output of the engine choice is critical.
Why you ask? Great question... It's simple.
Because the Harvester motor will be quite small relative to the size of the battery pack and small relative to the size of the truck and its curb weight. And, if you go by CarTEchGeek and the i3 example, then you are essentially using a scooter battery (34 HP) to send power to a motor directly. Yes, 34 HP!
This is also why Scout has a stake in the sand and has stated a 500 mi estimated RANGE for these vehicles (which is absolutely phenomenal BTW). All the naysayers wants to be able to drive for 15 hours straight without stopping for gas or energy. Why they want to do this type of torturous driving, I dunno. That's not for me, and I am perfectly happy to stop, charge, pee and eat while road tripping. Right now there is not a nuclear-optioned Scout to drive for ever.
Now, if you want to take away the EV benefits (including HP, instantaneous TORQUE and all of the additional storage space Scout has planned for everyone), then you could put a giant V6 in the frunk and build a RAM and pretend its an EV. Or you could put a Scooter motor in and skip the whole battery thing.
Even if you went full MAD MAX and filled the bed with all the gas from GAS TOWN, you would be pulling MORE WEIGHT and you would not recoup enough energy to drive for 15 hours at HWY speeds. The truck would simply consume more than it receives from the Harvester. Again there is a stated range of 500 for a reason.
So you agree with @CarTechGeek that diesel electrics do NOT send the electricity through a battery before powering the wheels?Dude, this is exactly how diesel electric locomotives work. They pull millions of pounds of cargo for hundreds of miles.
Series hybrids have been around since 1881.
How do diesel electric trains work, and why do they need turbochargers?
Why do diesel electric trains require both an engine and electric motors? And where do turbochargers fit into the equation? The answers may be surprising.
But its driving engagement!Heaven only knows. Kinda wish original OP would delete it-HaHa!
No-seriously!!!
We should start a poll with a Scout mug as a prize to the one who gets closest to the actual number of posts on the day Scout reveals the system fully.Heaven only knows. Kinda wish original OP would delete it-HaHa!
No-seriously!!!
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