FVT eVaro plug-in serial hybrid

[love the evaro]

Originally Posted by NeilBlanchard

Are the two motors hub motors?

Neil, there are two FVT custom built inboard motors, no transmission or gear box, they are the differential and will produce up to 2000 ft. lbs of torque
send me a privet message with your e-mail address and I will send you some pictures

cheers

[NeilBlanchard]

The FVT team and their eVaro have made it to the Michigan Speedway:





The final paint job will have to wait; but they made it!

[rgathright]

Nice car...

I also like the yellow and green concept cars behind it to.

Actually, I'm just a sucker for anything sporty and eco-friendly.

[NeilBlanchard]

Here are pictures of the 20kW generator they made for the eVaro:





It uses the engine block of a Honda GL-1100 (Gold Wing) motorcycle, and everything is designed to run at a constant RPM. It is able to run the eVaro at highway speed, AND charge the battery in about 1 hour.

[dcb]

do we think recharging the battery with an engine is a good idea?

How many folks will actually plug it in if you allow that?

How less efficient is it when you use gas to pump up the batteries to drive the motor?

[rbrowning]

"do we think recharging the battery with an engine is a good idea?"

For those of us that commute anywhere near the stated range, this is a must. The stated range is under ideal conditions with new batteries. Add some snow to the road on three year old batteries and you probably won't make it home.

"How many folks will actually plug it in if you allow that?"

All of them that have ever ran their house on a gas generator when the power is out. The cost of gas generated electricity is prohibitive compared to the grid.

I still want one of these so bad I can taste it.

[rgathright]

I like the constant RPM idea. Alternators are notoriously picky about the right RPM for optimum output. In other words, the engine in this scenario will work because it has been tuned to the generator and not the other way around.

[love the evaro]

Originally Posted by dcb

do we think recharging the battery with an engine is a good idea?

How many folks will actually plug it in if you allow that?

How less efficient is it when you use gas to pump up the batteries to drive the motor?

The on board genet is something that can be an option when you buy the car, the main reason for the genset is that in real world driving an all electric car is some what useless with short range and having to plug it in before you make it to your destination, even thou the eVaro can do 120 miles on a charge it is not able to give us the freedom to go any where or as far as the gas powered car, With out that freedom the car is like any other electric car that limits us to short distances from home and long recharge times, With the on board genset it may only run 2% of most peoples drive time and will never leave you stranded or forced to plan short trips, Short range and long recharge times are what makes electric cars a real problem for most public acceptance, With out the genset, if I want to go on a trip that is only 90 miles from my home I would never get back home on a single charge so I would have to plan to recharge at my destination which would add another 9 hours to my trip as I wait for the car to recharge on a 110 plug, keep in mind not every where you want to go has recharge capabilities much less with 220 which will cut your recharge time in half, For now I think an electric car without on board recharge capabilities is more or les usless

[dcb]

Originally Posted by love the evaro

...

Nobody has directly addressed the question of recharging the battery from the ice, which is the most inefficient use of gas.

Neil said it would recharge the battery in an hour while driving, that does not sound efficient to me as it is obviously larger than it needs to be if that is the case.

series as a range extender is an engineering shortcut, there are much more effient ways to move a car than to go from
engine -> generator -> charger -> battery charge -> battery discharge -> controller -> motor -> drivetrain -> wheels

i.e. engine -> drivetrain -> wheels.

All someone (or a bloody computer if the driver is a complete idiot, engineers make that assumption all too often such that it is now self fulfilling) has to do is engage the parallel drive when conditions are right and you will get far more range, and not be tempted to recharge your pack with gasoline as you are pulling in your driveway.

[NeilBlanchard]

The eVaro has about 120 mile range on the battery alone, so you would be silly not to plug it in. And, this is the most efficient way to use the gasoline -- think of the generator --> electric motor as the transmission. The reason we need a clutch and transmission is because it is hard to match the torque available with the speed you need to travel. In an ICE --> transmission, you almost never can use it at the optimum RPM; only when you get it up to the ideal highway speed.

As one of the FVT guys has said: internal combustion engines love to be run at a constant speed -- they love it!

The serial hybrid allows you to run the gasoline engine at it's most efficient RPM all the time, into a constant load. You use what you need to power the electric motor(s) and you collect the excess power in the battery, until it is fully charged, and then you can drive another 120 miles on the battery only.

So here's the scenario: you plug in the vehicle and charge it during the night. You drive up to 120 miles on that charge. If you need to drive farther, say a long all-day trip, the engine then runs for 1 hour, recharging the battery and letting you drive at highway speeds. You then can drive another 120 miles on electric only.

So, you charge it up before you start, and drive 2 hours at 60mph. Then the genset runs for 1 hour while you drive another 60 miles. Then you drive 2 more hours at 60mph on electricity. You have traveled 300 miles in 5 hours and the engine has only run for 1 hour.

If you need to drive farther, the engine runs for 1 more hour, and then you can drive 2 more after that on electric only; bringing the total to 480 miles in 8 hours with the genset engine running for just 2 hours.

Sounds pretty darn efficient to me!

The DC motors on the eVaro are custom made, and they are very efficient -- like 40% better than the AC55 used in the previous prototype, partly because they do not need any reduction gears. The eVaro is very fast" 0-60mph in ~5s. The genset engine is 1100cc -- there is no way that it could achieve that much speed all on it's own, because it is the peak power of the ICE that is used -- when you use a transmission, you cannot hit that peak very often.

Oh -- I almost forgot: in this serial hybrid setup (or in a pure EV), you get to have regenerative braking. The folks at FVT have worked very hard on this, and they are able to get all of the braking down to 5mph from the regen -- below 5mph, the friction brakes are also used to fully stop. So, in city driving, you lose only some energy to rolling friction, aero drag, and the last 5mph. By having the battery and the really efficient electric motors, you can regain a lot of the energy you used to accelerate the vehicle.

This is impossible to do in and ICE-only car, obviously.