Why no hybrid trucks yet?

[redpoint5]

A series hybrid would have no gearing except for the fixed ratio from the electric motor to the drive shafts. The engine would be off except when it's needed to top off the battery, and at that time would run at peak efficiency.

I know there is efficiency loss with all the energy conversion steps, but a series hybrid reduces complexity and allows the engine to operate only at peak efficiency.

[JSH]

Originally Posted by redpoint5

A series hybrid would have no gearing except for the fixed ratio from the electric motor to the drive shafts. The engine would be off except when it's needed to top off the battery, and at that time would run at peak efficiency.

True but a series hybrid is less efficient than a series / parallel arrangement.

[redpoint5]

Does the added efficiency justify the added weight, cost and complexity? It's not like the eCVTs are without their own efficiency losses.

I was a bit dismayed at how inefficient the BMW i3 in a series configuration was (31 MPG).

[JSH]

Originally Posted by redpoint5

Does the added efficiency justify the added weight, cost and complexity? It's not like the eCVTs are without their own efficiency losses.

I was a bit dismayed at how inefficient the BMW i3 in a series configuration was (31 MPG).

Toyota, Honda, GM, Ford and pretty much every other manufacturer that has made a dedicated hybrid came to that conclusion.

The Nissan Note with e-boost is the only dedicated serial hybrid I can think of.

[redpoint5]

Originally Posted by JSH

Toyota, Honda, GM, Ford and pretty much every other manufacturer that has made a dedicated hybrid came to that conclusion.

The Nissan Note with e-boost is the only dedicated serial hybrid I can think of.

There's some point between the size of a sedan and the size of a locomotive that a series design begins to make sense. Full-sized pickup trucks with 10 speed transmissions may benefit.

Don't those enormous mining dump trucks use a series configuration?

[freebeard]

GM eAssist is a mild hybrid. IDK if they put it in trucks.

Originally Posted by redpoint5

I don't know if there is an easy solution.

Originally Posted by DDG

3DFS - Software-Defined Electricity
https://3dfs.com
Download White Paper on Financial Benefits of Software-Defined Electricity. Clean Electricity Pays for Itself Within 2 Years. Direct Energy Savings. There is an instant reduction in the energy consumed by every load in a panel powered with clean electricity. Indirect Energy Savings.

About - 3DFS Software-Defined Electricity
https://3dfs.com/about
Software-Defined Electricity is a very powerful technology leverages Task Oriented Optimal Computing for better data and analytics to measure and control electricity in Real-Time.

The Software-Defined Power Grid Is Here
https://spectrum.ieee.org/energy/the...r-grid-is-here
This article appears in the July 2020 print issue as "The Software-Defined Power Grid." About the Author Patrick T. Lee is CEO of PXiSE Energy Solutions and vice president of infrastructure ...

Just pointing to it; I've no idea....

[redpoint5]

The Caterpillar 797 series trucks employ mechanical drive powertrains in contrast to the diesel-electric powertrains of similar haul trucks offered by competitors.[4] During initial development in 1997, a diesel-electric powertrain was considered for the 797, but this powertrain configuration was not developed because Caterpillar considered a mechanical drive powertrain more appropriate for market conditions at that time.

The 797 series haul trucks are equipped with a rear-axle-mounted, computer-controlled, seven-speed planetary transmission with a separate lock-up torque converter. Both transmission and torque converter use a common powertrain oil.

The BelAZ 75710 has a conventional two-banana setup but the wheels are doubled, one to an axle, like a scaled-up International Payhauler 350. For this reason it needs two 59/80R63 tires.[1] It also has four-wheel drive and four-wheel hydraulic steering which is unusual. It has a turning radius of about 31 m (102 ft).

The 75710 can carry a 450-tonne (440-long-ton; 500-short-ton) load.[2] With an empty weight of 360 tonnes (350 long tons; 400 short tons), it is much more heavily built than the previous largest model, the BelAZ series 7560, which weighed 240 tonnes (240 long tons; 260 short tons) when empty.[3] [4] It is 20.6 m (67 ft 7 in) long, 8.16 m (26 ft 9 1⁄4 in) high, and 9.87 m (32 ft 4 5⁄8 in) wide. The bed is relatively shallow, limiting the volume of material that can be carried.

Instead of a single engine, the Siemens MMT 600 drive system is powered by two MTU 65-litre (4,000 cu in) 16-cylinder four stroke diesel engines, each with 2,300 horsepower (1,700 kW). These are coupled to two AC alternators and four AC traction motors (two in each axle.[5] Fuel consumption (according to company data) is 198 g/kWh (1.94 oz/MJ) per engine, with option to run on only one if carrying less than capacity loads. Maximum speed is 64 km/h (40 mph), and economy maximum speed (when fully loaded and on a 10% gradient) is 40 km/h (25 mph).[6]

Here's a series hybrid truck.

[JSH]

Originally Posted by redpoint5

There's some point between the size of a sedan and the size of a locomotive that a series design begins to make sense. Full-sized pickup trucks with 10 speed transmissions may benefit.

The Ford Hybrid has a 10 speed transmission because it is a single motor hybrid with the motor sandwiched between the engine and transmission. Far easier to do (and likely cheaper) than building a dedicated hybrid powertrain like the one found in your Prius.

Yes, giant mining trucks are series hybrids. They are also very slow speed vehicle. From what I've read the efficiency benefit of driving the wheel directly is at highway speeds.

[ksa8907]

Originally Posted by redpoint5

I'll have to research this a bit more, but it might be complex to get a solar inverter to function with a battery instead of solar. The inverters are designed to utilize the grid as a battery, so any "excess" electricity is fed back out to the grid, and any deficiency is pulled from it.

If it's being fed a DC voltage from a battery, it would always have "excess" and any attempt to feed that excess to the fake grid we've created would not be good.

I don't know if there is an easy solution.

The solution is for the inverter to not be the grid-tie variety. As the battery is discharged the vehicle will ramp up power from the engine to match the discharge, just as though it were being drained by the drive motor.

Edit: not to be used as a grid-tie, flip off the main breaker

[redpoint5]

Originally Posted by ksa8907

The solution is for the inverter to not be the grid-tie variety. As the battery is discharged the vehicle will ramp up power from the engine to match the discharge, just as though it were being drained by the drive motor.

Edit: not to be used as a grid-tie, flip off the main breaker

Right, I know there are purpose built inverters for local storage, but that's not what we've got because we had no intention of spending money on a battery system (it's not worth the investment unless it can offset peak rates, and we don't have TOU pricing here).

What's missing to make it capable of being tied to a battery instead of grid? Probably not worth the engineering effort, but it's a shame to spend another $3k to get a different one that is designed to feed a battery.

I'll research this some more, but like all inquiries that involve "off-label" use of a product, the internet mob will revolt for even considering an unconventional approach.