Range extender !

Mitsubishi i-MiEV Forum

Help Support Mitsubishi i-MiEV Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
So I got my pusher registered last week, no problem at all registering a homebuilt with a California title.
I removed all the ugly old wiring back to the original harness connectors and went forward from there, so the lights are now nice n bright. I cranked the throttle wide open and did a test commute today, starting at 60% SOC and finished up at 80% after 18 miles, pushing in third gear and lugging the dead engine through a small town and other semi-civilized areas. Being "lugged" with the ignition switch off lets enough fuel vapor into the muffler for impressive backfiring, even with a fuel shutoff solenoid (that I'm told disables only the main jet, not the idle jet).
(Yes that would probably make mine the most-polluting hybrid of our modern era!)

Otherwise, not a hint of overheating or other issues with the engine. Lugging it without firing certainly cools it down in a hurry! I'm also surprised by how little drag is added by lugging the engine. Once it starts spinning, it just smooths out the trailer ride at the cost of a 'few' more amps. The engine in fourth spins smoothly down to 8 mph before bucking. In third, it's down to 1 or 2 mph- literally just complains in the last second of stopping. The only time it feels like a conventional bouncy trailer is when pulling it in neutral with the engine stopped.

In third gear the engine has plenty of power to maintain speed on the level while also putting max regen into the car around 35-45 mph. Another test will be to time a pusher-powered fast charge from 20% to 80%!

I've also built a control box for the clutch and throttle actuator, and rather than bothering with limit switches, I've installed an ammeter on the box, thinking to watch for the amps to climb as the actuator motors stall at each limit of travel. Hoping to get that finished up this evening in time for tomorrow night's unveiling at the Seattle EV Assoc. meeting. That'll be the first 'long trip' and my first attempt to track fuel economy.
Awesome. How are you controlling the actuators? I've been wondering if RC servos would be strong enough for something like this. That way, the RC throttle on a plane controller can control the power output of the gas engine on the fly. Then just flip the flaps switch to engage/disengage the clutch or a toggle switch controlling ignition.
I'm just using a DPDT switch to reverse current through the actuator motors, and an analog ammeter (salvaged from a dead battery charger) is giving me a nice signal to tell when they've reached the end of travel (amps suddenly jump when the little permag motors stall out in either direction). Took my first drive with the new control box this morning. The lighted toggle switch that controls ignition is a very nice thing, but I need to refine the clutch actuator. It isn't disengaging completely. One thing I've been nervous about is bending or breaking one of the arms which moves the throwout bearing due to the huge torque of that seat adjustment motor. I think a pneumatic/vacuum actuator would be better to provide just the right amount of force, but the plumbing is more complex, and a leadscrew doesn't leak down like pneumatics would. Time to tune the force and travel with a lever and/or spring...

This exercise has also convinced me how oblivious most people are to spectacle. Most don't give the rig a second glance, and even the cops I've passed just seemed to give a quick look at the shiny license plate and move on....

Here it is topping off the charge at my office.

General update- I took my longest trip yet with the pusher trailer this week. 353 miles total with a single quick charge and one L2 charge en route. Otherwise, it was all hillbilly-hybrid! There were two 145 mile highway legs and 63 in-town miles in-between, during which I was towing around the dormant pusher.

Pusher control is still binary- meaning it's either running at wide open throttle, or not... This is enough power from the salvaged 1600cc aircooled VW engine to average 65 mph on hilly interstate, using the electric drive to boost power up the hills, and scrubbing off speed with regen on the way down (though I also slowed to 60 mph uphill and sped to 70+ downhill). That is 'charge sustaining' mode, in which I maintained SOC within two bars over more than 100 miles.
In this charge sustaining mode, I once again hit 19.5 mpg. BUT, throwing in the around-town errands at my destination, the trip averaged 24 mpg overall. Not great, but a bit better than I could have expected with the family minivan.

Economically, I would've been better off with a borrowed pass to the West Coast Electric Highway, as I refuse to pay Aerovironment's $7.50/session DCFC fee for non-subscribers, and it was logistically very helpful to not spend almost four extra hours waiting on charging sessions... The approximate $32.32 I spent on gas and $10.10 I spent on EVSE come out to 12 cents per mile, which is a lot more than MR BEAN's long term average of 2.4 cents, but equals the fuel-only cost in our minivan.

SO in summary, no better-than-OEM hybrid mpg numbers or great financial savings to report, but enough to continue refining the pusher, perhaps with a tune-up and throttle control.

The maneuverability of an i towing a trailer is compromised ONLY by parking stalls, and that's not bad when the tongue length is tuned to allow a full 90 degree parking angle between car and trailer (especially for an i at charging stations). Otherwise it can still go anywhere.

*update* it attracted some interesting attention on the Chevy Volt facebook group, will try to post a link later from home....
Here's the hubbub I generated on a Volt forum. Lotta ignorant speculation on display......
That Anthony Vigil sure has to say a lot of trash on everything but the Volt. I've driven the Volt, and though it's a nice car, I feel a lot needs to be tuned on it to make it so much better.

My parents have a C-Max hybrid (non-plug-in), and yes it can sustain highway speeds in EV mode. Can't accelerate with gas, but can definitely maintain speed. My only complaints about it are weak regen (when you have a small battery, what choice do you have?) and a very wide turning radius. I think the F-150 makes tighter turns. Either that or I'm really used to the i-MiEV's two-lane U-turn.
I thought that the responses to the Facebook post were just hilarious. But PV1 is right about Anthony's trash talk. I still believe that a range extender is a great idea, now to re-visit the hydrogen fuel cell extender.....

But I will take on any Volt owner when it comes to comparing cost per mile with my iMIEV considering my purchase price of $10k with about 2,300 miles. The Volt owners that I have spoken to here in Phoenix are either in leases, which still have a much higher costs basis, or have purchased, which is an unacceptable price for me to pay for any car. Even used Volts are substantially higher in price from what I can tell.

Ok, and one other question, I wasn't sure from reviewing the prior posts on the subject on the mechanism used to re-charge the battery while you were driving? Or did I miss it in the posts?
Well, since the VW is pushing the i-MiEV, recharging the main pack is as simple as engaging regen with the pusher running. As seen on the Facebook page, charging stations are also used.

The VW gets 12 volt power from the i-MiEV.

I'll take the i-MiEV with a pusher over the Volt. There have been so many trips that the i-MiEV does on electricity that would make gas a requirement in the Volt. The pusher is reserved for long-range travel, though with a recent explosion of quick chargers in my area, I don't really have a need for a pusher. CHAdeMO is my new range extender :mrgreen: .
If I had the time I would take a salvage WRX250 250cc water cooled motorcycle or something similar and convert it to a mini version of the VW pusher.
I'll second GDB that a motorcycle-based pusher should be very good. I took another long pusher trip last week, this time with my wife as accessory to the crime! We drove through the metro area on electric and then stopped for a fast charge and energized the engine once we found some virgin air to pollute. Starting from under 100' elevation, we pushed over Tiger Mountain Summit at 1375 feet, Snoqualmie Pass at 3022 feet, and then down and up Blewett Pass at 4102 feet.

We went 159.7 miles with one 4.81 kWh fast charge boost and exactly 5 gallons of gas (ran out of fuel before cresting Blewett Pass and made it over the top with less than two bars). That last 26 miles into Leavenworth almost made me nervous, but we finished up with less than one mile on the turtle, after the downhill grade leveled out in town.
I think Volt drivers would call that 32 mpg in Mountain Mode. TESLA drivers might call it a hamburger run... My wife calls it tolerant. :|

Similar results on the return trip, though we took a longer route and refueled once; no CHAdeMO.
As mentioned when I made this trip on electric only last year, the i-MiEV can barely maintain regen at highway speed, even with miles of 7% grade- UNLESS you've got a pusher behind you. Then it's full regen at cruising speed (with instant engine braking at your disposal in case of elk encounters).

Thank you PV1. I'll agree that CHAdeMO is my preferred range extender within the metro area, but the novelty quickly wore off for highway trips, especially when trying to keep a schedule but running into lineups of LEAFs or a DCFC station out of order.
I would love a small auxiliary suitcase style battery pack, that I could put in the trunk. All I want is another 10 miles.
jray3, you're now famous ... or is that infamous? :ugeek:

Using a motorcycle as a pusher could prove to be a relatively simple implementation, especially if you already own a motorcycle and have a trailer hitch on your i-MiEV. Google "motorcycle towing cradle" to see the possibilities. :geek:
Thank you Joe and Phximiev. :cool: We'll see if I get a nastygram from Mitsu now. So far, they've acted oblivious to everything that happens once we leave the dealer lots, and at this point, a continuation of that practice would be welcomed.

Surprisingly, I continue to be surprised by folks who don't get the point and feel compelled to enlighten me that a Prius or Volt or whatever would be better for a long highway trip. BOOring and NOT cheaper, and despite some ASSumptions, not less polluting when one stretches out the numbers. Carting around more car than we 'mericans need 99% of the time digs a deep hole that is very difficult to drive out of, even if comparing 19,000 electric miles plus 1000 pusher miles per year to a 20,000 mile per year hybrid. I just re-ran the numbers, and I'm at over 800 miles now on the pusher, so time to get serious about emissions and safety improvements. (Plus I dislike averaging 20 mpg in charge sustaining mode.)

I've picked up a good 2 kW propane genset (vintage salvage in keeping with my theme). Am torn on whether to mount that to a pusher for dual modality (plus I could rig that propane regulator to also supply the pusher engine for cheaper, cleaner fuel). No desire yet to charge and push, just to charge OR push. Am thinking to preserve the pusher for posterity in it's original form, but continue the experimentation with my lighter-weight plywood-bodied pusher, built before we resurrected the Straubel pusher.