Electric Assist Project: E-charger (2000 Subaru Outback)

[bwilson4web]

Originally Posted by brucey

[IMG]. . . I think the huge increase came because I figured out how to use it properly and I was subsidizing the gasoline use heavily with electricity.

What you've built is called a plug-in, hybrid since the energy comes from the grid.

Originally Posted by brucey

[IMG]. . . Other hybrids are not currently doing this, they're mainly using the electric for regen abilities.

One of the earliest 'lessons learned' is the futility of maximizing hybrid performance by trying to use regenerative energy. Regenerative braking helps but it there are other aspects to hybrid efficiency . . . for the efficient ones.

Bob Wiilson

[Phantom]

I'm assuming that you missed my post a few pages ago since it was the last on one the page and was posted just after one of yours, so I will repost it.

Originally Posted by Phantom

Have you considered adding an injector kill switch? If you did that you could warm the engine then cut the injectors at a stop or roll as you do this open the throttle 100% and use the electric motor to turn the engine and trans for city driving. That would reduce pumping loss and should keep the electronics on in the car, the one thing you will need to remember is to let off the throttle and shift into neutral when you are ready to restart the engine.

[brucey]

Oops! Yeah, missed that one.

That's a possibility. Although at that point I'd be fighting with 2 throttles, the automatic transmission, the gauges, plus the fuel cut. It was getting a bit busy with just the first 3! Although If I could get a fuel cut and open the throttle up it would basically be a (very inefficient) pure EV at that point!

[dcb]

Originally Posted by bwilson4web

...
One of the earliest 'lessons learned' is the futility of maximizing hybrid performance by trying to use regenerative energy...

Just so people don't get too trapped in this mentality, electric hybrids (due to all the conversion losses) currently don't recapture a whole lot of regen. But systems, like hydraulic hybrids, do show a lot of promise in capturing and returning a significant portion of braking energy.

[Phantom]

If you were to keep the set up I would work on automating the throttle on the electric motor.

Something like this: (e= electric motor throttle, TPS= Throttle position sensor of engine)
If <25mph = 20%e
If TPS >10% = 1-100%e
If Load >x = 1-100%e
If TPS 0-2% and MPH >47 = regen
If brake is applied = regen

The actual percent of applied assist would be based on engine load using the MAP sensor. That way if you can cruse at 70mph with 7-9% throttle normally, but up hills you need 12-25% to maintain 70mph due to the extra load, the controllers throttle will aim to keep the load consistent allowing the car to climb the hill at 12% instead of 25% throttle.

[SolarSaab]

Most awesome work on this project!
I agree with Phantom, that an automation of the motor/ generator would be a huge help. Once you fully electrically and mechanically integrate the systems, your efficiencies will jump.

Do you have an amp meter on the motor wiring for both in and out (throttle and generator modes)? What type of volts/ amps are coming off during regen mode?

Have you thought of deleting your alternator and pulling a 12V string from the motor during regen mode? You'd probably need to add another AGM to replace your OEM battery to get more AH, and some onboard solar connected to it to help extend range. It seems like the standard alternator is just in the way if you already have a larger generator source on board, plus its fighting the motor when it engages (rectifier turns on and causes mechanical resistance when your battery needs juice).

You could pull a string wired to engage during regen, drop it to 12v, run it into a charge controller with the solar and then to the 12v.

Again, many props, most impressive!

[Dr. Jerryrigger]

Awesome, I haven't checked in on this for some time now. Now just swap the EJ25 for an EJ18.
Any plans to tie the throttles together? A fuel kill switch would be much simpler to use if your electric motor was controlled by the throttle position sensor.

[Logic]

Originally Posted by Dr. Jerryrigger

I've thought about this (but haven't done anything) and came up with a few possibility:
2- mill gear teeth into your brake disks (2 or 4 of them) and mount a little brushless motor to you strut mount. This would require a lot of machining and you would only be able to gear it for the highway, but that might be okay...

Noise (see straight cut gears)
Wear and lubrication: You want to what? Grease a gear cut in your brake disk? Or run it dry and gratingly load and replace monthly?

Originally Posted by Dr. Jerryrigger

3- (the one I'm considering at the moment, if only I had the $$) A electric assist boat tail trailer. Two birds with one stone. It would be a little hairy having a trailer pushing your car, but with the right linkage it could work out. This idea needs much more planning.

E-motors make sense in town due to recharge on braking.
ie: As town driving is what we all do most, you want the E-motor in the car if you don't want to tow a trailer around town and try find and do parking.

An ICE engine at constant rpm/speed can be made way more efficient than ICE expected to rev from 500 to 6000 rpm.
You can tune ignition and fuel easily, and max efficiency at fixed rpm things like cams, intake tract lengths, tuned length exhaust lengths.

ie: A pusher trailer should not contain an E-motor.
It should contain an efficient ICE without a gearbox.
So direct drive from an ICE or don't do it.
You also get extra space for long trip luggage.

Originally Posted by Dr. Jerryrigger

For manual controlling of the motor; I was thinking a T-handle throttle from a boat would do the trick (and with style), with a switch to put it into a charging circuit for slowing.

What are you wanting? Do you want to drive around on the motor alone, with the engine off?
Or do you want engine assist on acceleration and charge on cruise if reqd and regen on braking?

I have posted about a very easy way to get elec assist with no motor control issues here somewhere, using E-bike kit, including their torque sensors.


If you want to drive on elec only; do an elec conversion, keeping the gearbox so a smaller cheaper motor suffices, and put the engine in a 1 wheeled trailer that connects to the car with a large universal joint:

A UV joint allows left and right turns and up and down over bumps, but the only way the trailer can fall over to the side is if it twists the car into falling over with it.
(You may want to stiffen up the car's rear anti roll bar a bit. There are kits for that or its pretty simple to DIY)

One center wheel requires no heavy, power sapping differential.
Run a properly geared chain to the wheel with a freewheel sprocket.
In fact; sell the engine and get a smaller lighter one: you only need around 20kw to cruise.

All this will take some maths and engineer type thinking it through!
But not too difficult if you ask the right questions.

[Logic]

Originally Posted by bwilson4web

One of the earliest 'lessons learned' is the futility of maximizing hybrid performance by trying to use regenerative energy. Regenerative braking helps but it there are other aspects to hybrid efficiency . . . for the efficient ones.

Bob Wiilson

See my post here, where E-bikers will be trying this:
https://endless-sphere.com/sphere/th...0/post-1828002

NB that E-bikes + a rider have the areodynamics of an outhouse with the door open so they slow down fast.
Then they have low weight, so no low speed momentum to speak of.

Yet they still get at least 5% from regen and way less brake pad changing.

Momentum P = 1/2.m.v squared.

An eco car has way better CD and way more momentum, so the above idea to be able to capture more of the power from braking will work way better.

If there was nothing to be gained from regen, there would be no reason for hybrids.
The BYD cars are serial hybrids with a direct top gear for cruising.
They do 200 km/l.

[freebeard]

ie: A pusher trailer should not contain an E-motor.
It should contain an efficient ICE without a gearbox.
So direct drive from an ICE or don't do it.
You also get extra space for long trip luggage.

I'd had hopes of getting an Arcimoto FUV. They only have a range of around 100 miles. My thought was to convert a Vespa motorscooter to a single-wheel trailer (On the reverse tadpole) and give it an electric clutch.