Towable Generators

[Kevin Harney]

So what would your range increase to using a 30KW Genset at highway speeds - say an average of 50-60 mph (which is really a highway speed of around 70 mph figuring in stops etc..) I don't think any reasonable person would ever expect to travel more than 720 miles a day (60 mph x 12 hours). That would effectively be unlimited mileage. And then on top of that you could charge all night while you sleep and start fresh the next day.

[TEG]

Steve Hawkins' Long Ranger

RXT-G 3-Phase AC
AC-150 70kW configured for 7,200rpm 70a
continuous output of 24kW.
Drivetrain: Kawasaki Ninja EX-500 powered ACP AC-150 converted to a generator system.

ACP specs

[doug]

See also this other thread about REEVs since the power requirements are similar. (Though usage may be different since you're likely starting with a lower capacity battery.)
http://www.teslamotorsclub.com/techn...-concerns.html.

Be sure not to confuse power and energy.

[WarpedOne]

So what would your range increase to using a 30KW Genset at highway speeds - say an average of 50-60 mph

According to data from Roadster Efficiency and Range, Roadster needs about 15kW for constant 60mph.
With 30 kW gen-set your range would become practically limitless at that speed. Things could change with many stop 'n' goes, climbing hills etc.

30 kW is overkill. We should be aware that engines capable of 30kW of CONSTANT power output are very heavy. very loud, very big (think truck or bus engine). That genset linked above with 24kW output would have very short lifetime (a year max) as it is using a bike engine. Bike engines see very low average power (under 10kW) so they can afford to be light and still have high max power. They are very high-maintenance things though.

Gen-set could have normal operating mode at say 5kW with low noise and high durability and performance mode for times you really need that extra energy and are willing to sacrifice some durability.

[stopcrazypp]

See also this other thread about REEVs since the power requirements are similar. (Though usage may be different since you're likely starting with a lower capacity battery.)
http://www.teslamotorsclub.com/techn...-concerns.html.

Be sure not to confuse power and energy.

The REEVs are definitely related, only difference is what you mentioned and also that they have internal generators.

However, it seems right now the REEVs have "range extenders" which are intended to be the primary source of power after the battery is depleted while minimizing the need to draw power from the battery (since presumably it is near depleted or has reach a threshold level where you don't want to deplete much further). For this application then the 75kW that TEG mentioned will be more appropriate. This is because the generator also has to provide power for acceleration (so it needs more peak power).

In a towable generator, the intention is mostly to maintain highway speeds for long distance travel, with the battery providing power for other situations, so the power requirements are much lower (though it has to be continuous power rather than just peak).

[Kevin Harney]

yes but that genset being towed would only be used a couple times a year max and even then only for a couple days at a time maybe. I think it would be ideal to rent one for vacations just as one rents say a uhaul trailer.

[stopcrazypp]

yes but that genset being towed would only be used a couple times a year max and even then only for a couple days at a time maybe. I think it would be ideal to rent one for vacations just as one rents say a uhaul trailer.

Yes that would be ideal, but it seems like there is no one who is working on this idea and making some rentable genset trailers. Genset trailers in the mean time would be a lot more practical, cheaper, and easier to implement than other alternatives like rapid charging or battery swapping.

REEVs seem to get a lot more attention.

Of course the market for towable gensets right now would probably be very small, so it might get more attention after all the promised EVs get released.

[Kevin Harney]

There is a simple reason that the REEVs get more attention from others ..... The others have a range of ONLY 40-50 miles!!!!!! You would have to tow a trailer ALL THE TIME with that mileage With a 200+ mileage range you would only need the trailer for long trips.

[ZeroFossilFuel]

I have pondered many of these same questions I found in this and other related threads. But so far all it appears to be is theoretical discussions. Questions I still have are:

1) Has anyone actually tried interfacing a towable generator to the Roadster?

2) Is there a less conspicuous pigtail cable that can be added to tether the generator instead of connecting to the side mounted power receptacle?

3) Does the car's firmware even allow the batteries to be charged while the car is driven?

Under normal conditions I would likely never have the need but I would like the ability to take it on long trips from time to time, without a flatbed.

[TEG]

I have pondered many of these same questions I found in this and other related threads. But so far all it appears to be is theoretical discussions. Questions I still have are:

1) Has anyone actually tried interfacing a towable generator to the Roadster?

I have never seen such a thing done. I assume you saw the ACP gen trailer for the TZero and Rav4EV early in this topic though...

2) Is there a less conspicuous pigtail cable that can be added to tether the generator instead of connecting to the side mounted power receptacle?

The car may put itself in "park" when off/charging. The reductive charging might not work right if you tried to plug a charger in while the vehicle is in motion. Just speculation, but I bet you would have trouble trying to add charge to the vehicle while it is in motion. (The gearbox always turns the motor when the vehicle moves... no clutch to disengage it). I have never seen a Roadster charge from any connection other than the one under the charge cover.

3) Does the car's firmware even allow the batteries to be charged while the car is driven?

Well technically that is what regen is doing. A long time ago I inquired about the idea of having the Roadster charge itself when towed behind an RV. Somewhere along the way someone made a comment that such a thing is possible. So I suppose you could hook up a tow hitch between the front of the Roadster and an RV, turn on the Roadster and then start towing it and the battery would start charging based on regen.

Under normal conditions I would likely never have the need but I would like the ability to take it on long trips from time to time, without a flatbed.

This is a question many have pondered. The usual "solution" ideas are quick charge and pack swap. Neither seem to be reality now. Better Place suggests that they will have both technologies ready on a mass scale someday soon. Tesla more or less said they are considering it for Model S. Time will tell.