Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > MOTORHOME FORUMS > Electric RVs and EV Charging
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 05-12-2022, 02:22 PM   #1
"Formerly Diplomat Don"
 
Dutch Star Don's Avatar
 
Newmar Owners Club
Join Date: Apr 2005
Location: Moorpark, Ca.
Posts: 20,405
Towing an EV

I would really like to tow an EV truck four down. I know the Rivian came close, but later said they were not towable.

So, here's my question......I believe when an EV is going down a steep hill, it's actually coasting and charging at the same time. What would the difference be to just tow one with it on? It would simulate it going down a hill.

I'm sure there are several reasons why my simple logic wouldn't work....but why not?
__________________
Don & Mary
2019 Newmar Dutch Star 4018 (Freightliner)
2019 Ford Raptor
Dutch Star Don is online now   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 05-12-2022, 03:26 PM   #2
Senior Member
 
Skip426's Avatar


 
Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 25,837
From my limited time spent checking into EVs ; depends on the motor; some will charge the batteries others won't ,
The onboard charge system would have to recognize and disconnect according to the rate of charge ( speed ) and battery state of charge , to prevent motor and /or battery overheating.
I don't think the manufacturer is expecting a five + hour long downhill when it came to determining the rate of charge the motor would put back to the battery.

I'd love to see the next breakthroughs in EVs be this function ; towing to charge, and solar charging .
__________________
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 05-12-2022, 03:43 PM   #3
Member
 
Join Date: Oct 2021
Location: BC
Posts: 91
I think there are software issues that would need to be modified. On our Tesla the regeneration function (and a whole bunch of other things) won't work unless the car senses that someone is seated in the driver's seat. Also if you don't have your foot depressing the accelerator the car attempts to stop and once the car stops rolling it puts itself in "Hold" which locks up the wheels and they won't start rolling again until you push the accelerator pedal down some amount.

They would need to create a "tow" mode to get around these current functions.

Other than that I can't imagine an electrical or mechanical issue that would prevent an EV from being towed. As you say the regeneration happens when going down hill so what is the difference - except duration. A simple adjustment to the amount of regeneration (which is already done in software if the battery pack is cold or already fully charged) could regulate the amount of charge to some middle ground between coasting and full regeneration charging. Perhaps even coasting the motor/generator is creating significant current and doing that without putting it somewhere (or even putting it somewhere) for a long period of time causes problems??? Does not make sense to my simple minded knowledge of electrical/mechanical systems, whereas not wanting to tow an automatic transmission in an ICE car makes perfect sense to me if the transmission oil pump is not being driven by the drive shaft. Would like to know what the issue actually is with flat towing EV's other than the manufacturers just saying don't do it.
__________________
2004 35' Triple E Embassy Diesel
Little Red Truck toad (2003 Ranger Edge)
darnold9999 is offline   Reply With Quote
Old 05-12-2022, 04:38 PM   #4
Junior Member
 
Join Date: Jan 2021
Posts: 6
Seems like a locking hub similar to a Jeep application is needed. Simply set it to freewheel and tow away. Lock it for normal operation.
AKjohn62 is offline   Reply With Quote
Old 05-12-2022, 04:44 PM   #5
Senior Member
 
dizcom's Avatar


 
Freightliner Owners Club
Holiday Rambler Owners Club
Join Date: Jun 2021
Posts: 1,167
Can’t be done yet. No EV has the capability to be towed four down. Ford, interestingly, filed a patent for an EV system that recharges while being towed. I think that’s pretty exciting if you like EVs and pulling a toad. I keep wondering how much of a strain it will put on a motorhome, but I’m sure they’re working on it.
__________________
2021 Holiday Rambler Armada 44LE
2021 Jeep Wrangler High Altitude toad w/Ready Brute Elite II
dizcom is offline   Reply With Quote
Old 05-12-2022, 07:58 PM   #6
"Formerly Diplomat Don"
 
Dutch Star Don's Avatar
 
Newmar Owners Club
Join Date: Apr 2005
Location: Moorpark, Ca.
Posts: 20,405
Quote:
Originally Posted by AKjohn62 View Post
Seems like a locking hub similar to a Jeep application is needed. Simply set it to freewheel and tow away. Lock it for normal operation.
Hoping some industrious entrepreneur could come up with a hub that attaches behind the OEM wheel that can be set to freewheel.

Our SUV is gas but being retired we rarely drive it (wife's car). I only drive my truck short distances doing about 8K a year. An electric truck would be great for me, but would like it to be towable. I had high hopes for the Rivian.
__________________
Don & Mary
2019 Newmar Dutch Star 4018 (Freightliner)
2019 Ford Raptor
Dutch Star Don is online now   Reply With Quote
Old 05-13-2022, 03:15 PM   #7
Senior Member
 
Join Date: Apr 2005
Posts: 3,389
Hi Don. Sorry I don’t have an answer to your question as I don’t know enough about it. We towed an EV on a trailer for 5 years and friends towed their leaf on a dolly (I think they still are) but I can’t help with the 4 down. Maybe check in on one of the Rivian and Ford EV truck Facebook groups as to wether there is any kind of weight in seat requirement for the truck to operate. I know our Tesla does.

The other thing to consider would be tire wear on a vehicle being essentially dragged to some extent while charging.

Hope you find your answer Don and hope you come back to share with the board. You are going to be a pioneer in the field. .

Good luck Don.

John.
radar is offline   Reply With Quote
Old 05-14-2022, 08:18 AM   #8
Junior Member
 
Join Date: Jul 2016
Posts: 24
I’ve done quite a bit of thinking about this. Regen or not doesn’t really matter. The car/truck would automatically disable regen once the battery was fully charged.

Another factor is to keep the car from turning off without any driver input. If the car is shut off the motors won’t be getting proper lubrication and could be damaged.

My Volt shuts off after 2 hours with no driver input. My Pacifica eHybrid shuts off after one hour.
__________________
2015 F-150 XLT 4x4, 5.0L, SCab, Tow Package, 2019 lbs payload, 3.55 locker, 36 gal tank
2013 Keystone Springdale 253FWRLLS

People like to make generalizations.
easycamper is offline   Reply With Quote
Old 05-14-2022, 09:33 AM   #9
Senior Member
 
Join Date: Jan 2021
Posts: 1,905
We need to define the term “coasting”. Are we truly coasting if we remove our foot from the accelerator of a vehicle that has a default regen setting? In my opinion, we are not. Our PHEV has a default regen setting that closely simulates the feel of lifting off the accelerator in an ICE vehicle. There are 3 additional driver selectable settings, all of which offer relatively light regen. Only by selecting Neutral, will the car “coast” and not recapture kinetic energy through regenerative braking. Again, in my opinion, coasting does not produce regenerative energy.

This brings us to the aforementioned reference of “dragging” the car behind another vehicle in order to “recapture” some kinetic energy. The problem with this concept is that we’re using the kinetic energy produced by an ICE vehicle, or it could be an EV, to force an electric motor/generator to spin and generate electricity to charge a battery. A number of folks with very large brains have stated that regen is roughly 50% efficient. There’s no free lunch.

We’re looking at the Jeep Grand Cherokee 4xe, a PHEV which is flat towable. The electric drive system is upstream of the transfer case, rather than at the wheels/axles. This allows the vehicle to freewheel while being towed. We’ll just charge it at the campground or find “free” public charging while in town.
__________________
Alpine Coach ‘05 36MDDS
Kid Gloves is offline   Reply With Quote
Old 05-14-2022, 09:46 AM   #10
Senior Member
 
Join Date: Apr 2005
Posts: 3,389
Quote:
Originally Posted by Kid Gloves View Post
We need to define the term “coasting”. Are we truly coasting if we remove our foot from the accelerator of a vehicle that has a default regen setting? In my opinion, we are not. Our PHEV has a default regen setting that closely simulates the feel of lifting off the accelerator in an ICE vehicle. There are 3 additional driver selectable settings, all of which offer relatively light regen. Only by selecting Neutral, will the car “coast” and not recapture kinetic energy through regenerative braking. Again, in my opinion, coasting does not produce regenerative energy.

This brings us to the aforementioned reference of “dragging” the car behind another vehicle in order to “recapture” some kinetic energy. The problem with this concept is that we’re using the kinetic energy produced by an ICE vehicle, or it could be an EV, to force an electric motor/generator to spin and generate electricity to charge a battery. A number of folks with very large brains have stated that regen is roughly 50% efficient. There’s no free lunch.

We’re looking at the Jeep Grand Cherokee 4xe, a PHEV which is flat towable. The electric drive system is upstream of the transfer case, rather than at the wheels/axles. This allows the vehicle to freewheel while being towed. We’ll just charge it at the campground or find “free” public charging while in town.
Bingo. We towed an EV for 5 years (on a trailer) and never had an issue charging it. We occasionally charged in the campground but mostly it was just a matter of consulting the App on where the stations were and off you go. Shop at grocery stores or malls or restaurants with charging. Too easy. And probably cheaper than replacing tires on the car. .

Jmho.
radar is offline   Reply With Quote
Old 05-14-2022, 09:48 AM   #11
Senior Member
 
96 Wideglide's Avatar
 
Holiday Rambler Owners Club
Join Date: Aug 2010
Posts: 8,690
Quote:
Originally Posted by radar View Post

The other thing to consider would be tire wear on a vehicle being essentially dragged to some extent while charging.
Shouldn't be any excess tire wear. Tires are still spinning.
__________________
Ben & Sharon
2008 43' Holiday Rambler Scepter PDQ
96 Wideglide is offline   Reply With Quote
Old 05-14-2022, 10:00 AM   #12
Senior Member
 
Join Date: Apr 2005
Posts: 3,389
Quote:
Originally Posted by 96 Wideglide View Post
Shouldn't be any excess tire wear. Tires are still spinning.

I would disagree but am not an expert in this. The motor generator on each wheel is resisting the spinning of the tires. Essentially like riding a brake pedal. Anyone who has left their park brake partially on on a toad while towing knows the affect on the tires.

Regen is pretty intense on many EV’s. Our tow vehicle is an EV and even on a 6 degree grade our EV tow vehicle will bring the vehicle and the trailer to a stop on a 6 percent grade. There would have to be selectable software to control this. I believe some EV’s have more control of this than others.
radar is offline   Reply With Quote
Old 05-14-2022, 03:09 PM   #13
Senior Member
 
96 Wideglide's Avatar
 
Holiday Rambler Owners Club
Join Date: Aug 2010
Posts: 8,690
Quote:
Originally Posted by radar View Post

Regen is pretty intense on many EV’s. Our tow vehicle is an EV and even on a 6 degree grade our EV tow vehicle will bring the vehicle and the trailer to a stop on a 6 percent grade.
So, do you think your tires are wearing out pre-maturely?
__________________
Ben & Sharon
2008 43' Holiday Rambler Scepter PDQ
96 Wideglide is offline   Reply With Quote
Old 05-14-2022, 03:26 PM   #14
Senior Member
 
Join Date: Apr 2005
Posts: 3,389
Quote:
Originally Posted by 96 Wideglide View Post
So, do you think your tires are wearing out pre-maturely?
I would say no. But I’m not towing it for 100 kilometres at a shot to charge the battery.
radar is offline   Reply With Quote
Reply

Tags
tow, towing



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Towing Capacity and vehicle upgrades for towing acanania Trailer Towing and Tow Vehicles Discussion 17 10-23-2016 06:16 AM
Trailer towing or flat towing randys66gt Toads and Motorhome Related Towing 7 05-01-2016 11:02 AM
re: Towing older 5er, what to do for towing prep? BandSA 5th Wheel Discussion 3 07-09-2015 05:06 AM
Requesting Advice on diesel MH towing a Class B MH OR "Class B+" towing up to 10,000 ClassBPuller Toads and Motorhome Related Towing 2 11-02-2012 10:49 PM
Dinging towing (flat towing) Toyota F J Cruiser akasusie Winnebago Industries Owner's Forum 15 11-27-2007 10:18 AM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 12:58 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.