Quote:
Originally Posted by roflwaffle
There's plenty of data. A HH conversion for a pickup costs $13,000 plus labor, so probably around $15,000 and up. A factory 2-mode hybrid system carries a ~$4000 premium over a similarly equipped model out the door. Certainly an OEM w/ a HH option would charge less than $15000 since they can purchase in volume, but I haven't seen anything to indicate that it's cost competitive w/ battery electric hybrids. |
Is it fair to compare a factory electric hybrid to a conversion HH?
How much would it cost you to convert a Corolla to an electric hybrid?
Probably a lot more than any HH conversion.
Accumulators are very simple. Think of a bottle of nitrogen you get from the welding shop. Then place a very strong balloon inside the bottle. Precharge the balloon to 1000 PSI. Pump fluid into the bottle and collapse the balloon.
Life expectancy is measured in thousands of hours of continuous operation, and when the balloon fails, you buy a rebuild kit, that is basically a new balloon, for less than $100 bucks.
Been around forever. Very mature technology. Used as backups for landing gear in aircraft. Virtually impervious to temperature variations. Used in excavators. and other heavy equipment.
In the same way your shock absorbers smooth out the ride in your car, and accumulator smooths out the huge variations in energy demand and recovery in a HH vehicle.
Why do we need huge batteries and capacitors to do what the simple accumulator has been doing for decades, even centuries. In England before they even had electrical power transmission they used hydraulic "water engines" driven by pressurized water from giant centrally located steam engines in the late 1800's. Boiler explosions were serious concerns and water engines were impervious to fire.
Look at this objectively. Pulse and glide is proven to be efficient. it's simple and totally effective. When you pulse and glide, your car is the accumulator.
To incorporate P&G into the vehicle, you need to accumulate energy and apply it consistently. The accumulator allows you to do this, when you combine it with an Infinitely Variable Transmission that has no fixed gear ratios.
This allows you to pulse and glide the accumulator and engine, while applying the exact same amount of power to the wheels by constantly increasing the displacement of the in wheel IVT as the accumulator pressure declines.
No vehicle speed changes necessary.
When the accumulator pressure approaches its minimum level, the engine fires up and pressure in the accumulator rises as the IVT displacement reduces to maintain a consistent X value of horsepower to the drive wheels.
It's not all wheel drive because I like AWD (although it's very useful in low traction situations). It's because you must recover energy from every wheel for greatest regeneration efficiency. Any individual wheel can be set to neutral (no stroke-no displacement) any time at any speed, almost instantaneously.
If you can drive your car every day using only the emergency brake (and many here probably can) then you would only need 2 wheel regeneration.
Is it practical to sell a car like that?
Nope.
Burn and coast, P&G, hypermiling, call it whatever you like, but it is basically turning your car into a hybrid, by storing inertia in the mass of your car itself.
With an accumulator and in wheel IVTs you do the same thing tactically, without the speed variations necessary in P&G.
The IVT is the crucial component. The EPA designs were inefficient at higher speeds because the hydraulic motor speeds were too high. In wheel drives reduce motor speed by 75%, where motor efficiency is in the 90+% range.
Revolution sensors in the wheels used in ABS and traction control are another requirement, to provide the speed signal for the control unit to adjust the IVT displacement to maintain speed while energy storage is depleted. The effective gear ratios in the in wheel drives would be constantly changing.
The OP in this thread addressed the issue of combined energy losses in series hybrids. That is the core understanding of this design. Is it to hard to believe that you can actually build a simpler and less expensive system and accomplish what we do with P&G with a lot more driver input than the average driver would tolerate?
Simple
Robust
Long life expectancy
Less expensive than conventional configuration
(when you compare factory mass produced examples of both types-not factory produced versus conversions- which is really not a fair comparison)
Like I said before, if your situation only requires short range operation, then use a battery for your primary power source.
If you need greater range use IC or other methods of propulsion.
In the same vehicle which means you can have both for less than the price of a Nissan Leaf.
regards
Mech