BEV as a toad behind diesel pusher

[Durb]

As the BEV/RV capability debate rages on, I have couple of questions regarding the viability of an electric car being used as a towed vehicle.

First, are some even rated as being capable of being towed four down?

Second, if towed behind a DP could it be set up so regenerative braking allowed the car to be charged completely when arriving at a destination? Would the electronics allow that? Would the process create too much drag on the tow vehicle?

Third, can some BEVs be charged by plugging into a 50 amp pedestal without heavy supplemental equipment like transformers and DC convertors?

Possibly, some manufacturer can carve out a nice niche by addressing these issues.

[valhalla360]

Reisender wrote:

JRscooby wrote:

valhalla360 wrote:

A few minutes braking on the downhills won't add much to the battery pack. Regenerative braking is mostly about recovering the acceleration power used.

I don't recall any long downhills on that stretch...for the most part, you don't even need to touch the brakes to keep speed under control...but let's say you find a 2min stretch of downhill where the regen is putting out 50kw. That's going to generate a whopping 1.6kwh on a car that likely has a 80-120kwh battery bank. Even if you find 10 downhill stretches on the stretch of road you mention, that's only 16kwh. In much of the country, I never have to touch the brakes to keep the speed at the limit.

EVs are known to eat up tires in the first place (without locking up the tires). Trying to meaningfully slow down a 30,000lb MH is only going to accelerate the issue.

I picked that section of road, because Ks is known to be flat. As for "never use the brakes" I don't know about the air drag of a MH compared to the light weight, so you may not need to slow. I know that most times I'm on interstate I try to hold my speed real constant. Pick up speed going down, it looks like you are struggling to get up. Like a old outlaw told me when I first started "Put on what you want to haul, but never put on more than you can step with" 3 trucks on a small grade, 1 be struggling, he will get stopped. Because I would often run fat, I would always have my old snot turned up so I could pack a jag, and look right.
And tire slip will limit how much the toad will slow the combination, but most interstate travel, with the MH supplying the power, nothing will be coming out of batteries. But most anytime the rig slows, even to reduce speed to match a slower vehicle while a faster overtakes you, a little of the wasted energy could go in the battery. Would it get the battery from half to full in the course of a day? Don't know. But I would bet my last dollar a ICE has no more gas in the tank than when started at end of day, unless you pumped it there.

"EVs are known to eat up tires in the first place" I did not know this. Any idea as to the why of that?

It’s just how people drive them. Lots of horsepower and crazy torque. Hard not to have fun with that. Usually they have settings where the driver can dumb the car down somewhat so it makes it easier for the driver to “resist the urge”. In a Tesla it’s called “chill mode”. We use chill mode in winter and on snow. Works well. But come dry roads and spring I’ll be turning that off again. What’s the fun in that. :). Zero to 60 in 4. Woohoo. But yah, hard on the tires. Good year and Michelin have both designed tires just for EV’s now.

I suspect a lot of it is driver behavior and slowing a 30,000lb MH will be much closer to an aggressive driver.

Also, EVs use low rolling resistance tires. Trades off some durability for a couple more miles per charge.

[JRscooby]

time2roll wrote:
My Mach I Mustang 4 speed was hard on tires too. Mostly the rear. Could have been the driver.

Back in the day guys would ask me why I would ride the little 50 cc around town, instead of my Z-1 Kawasaki or Panhead. Panhead, worried somebody would steal. Z-1? Much more fun to ride a bike that struggles to break the speed limit as fast as I could make it go than keep a real fast bike below the limits

[time2roll]

My Mach I Mustang 4 speed was hard on tires too. Mostly the rear. Could have been the driver.

[Grit_dog]

Lol. Most “Teslas” can kill tires as fast As the owner wants to drive. Most other EVs would be embarrassing to pretend to be a racer in!
EV specific tires? Another lol. That’s called marketing, son. No more, no less.

[JRscooby]

Reisender wrote:

It’s just how people drive them. Lots of horsepower and crazy torque. Hard not to have fun with that. Usually they have settings where the driver can dumb the car down somewhat so it makes it easier for the driver to “resist the urge”. In a Tesla it’s called “chill mode”. We use chill mode in winter and on snow. Works well. But come dry roads and spring I’ll be turning that off again. What’s the fun in that. :). Zero to 60 in 4. Woohoo. But yah, hard on the tires. Good year and Michelin have both designed tires just for EV’s now.

Thank you. As I suspected, it is not the car wears out tires, it is the driver. Probably best I don't get one!

[Reisender]

JRscooby wrote:

valhalla360 wrote:

A few minutes braking on the downhills won't add much to the battery pack. Regenerative braking is mostly about recovering the acceleration power used.

I don't recall any long downhills on that stretch...for the most part, you don't even need to touch the brakes to keep speed under control...but let's say you find a 2min stretch of downhill where the regen is putting out 50kw. That's going to generate a whopping 1.6kwh on a car that likely has a 80-120kwh battery bank. Even if you find 10 downhill stretches on the stretch of road you mention, that's only 16kwh. In much of the country, I never have to touch the brakes to keep the speed at the limit.

EVs are known to eat up tires in the first place (without locking up the tires). Trying to meaningfully slow down a 30,000lb MH is only going to accelerate the issue.

I picked that section of road, because Ks is known to be flat. As for "never use the brakes" I don't know about the air drag of a MH compared to the light weight, so you may not need to slow. I know that most times I'm on interstate I try to hold my speed real constant. Pick up speed going down, it looks like you are struggling to get up. Like a old outlaw told me when I first started "Put on what you want to haul, but never put on more than you can step with" 3 trucks on a small grade, 1 be struggling, he will get stopped. Because I would often run fat, I would always have my old snot turned up so I could pack a jag, and look right.
And tire slip will limit how much the toad will slow the combination, but most interstate travel, with the MH supplying the power, nothing will be coming out of batteries. But most anytime the rig slows, even to reduce speed to match a slower vehicle while a faster overtakes you, a little of the wasted energy could go in the battery. Would it get the battery from half to full in the course of a day? Don't know. But I would bet my last dollar a ICE has no more gas in the tank than when started at end of day, unless you pumped it there.

"EVs are known to eat up tires in the first place" I did not know this. Any idea as to the why of that?

It’s just how people drive them. Lots of horsepower and crazy torque. Hard not to have fun with that. Usually they have settings where the driver can dumb the car down somewhat so it makes it easier for the driver to “resist the urge”. In a Tesla it’s called “chill mode”. We use chill mode in winter and on snow. Works well. But come dry roads and spring I’ll be turning that off again. What’s the fun in that. :). Zero to 60 in 4. Woohoo. But yah, hard on the tires. Good year and Michelin have both designed tires just for EV’s now.

[JRscooby]

valhalla360 wrote:

A few minutes braking on the downhills won't add much to the battery pack. Regenerative braking is mostly about recovering the acceleration power used.

I don't recall any long downhills on that stretch...for the most part, you don't even need to touch the brakes to keep speed under control...but let's say you find a 2min stretch of downhill where the regen is putting out 50kw. That's going to generate a whopping 1.6kwh on a car that likely has a 80-120kwh battery bank. Even if you find 10 downhill stretches on the stretch of road you mention, that's only 16kwh. In much of the country, I never have to touch the brakes to keep the speed at the limit.

EVs are known to eat up tires in the first place (without locking up the tires). Trying to meaningfully slow down a 30,000lb MH is only going to accelerate the issue.

I picked that section of road, because Ks is known to be flat. As for "never use the brakes" I don't know about the air drag of a MH compared to the light weight, so you may not need to slow. I know that most times I'm on interstate I try to hold my speed real constant. Pick up speed going down, it looks like you are struggling to get up. Like a old outlaw told me when I first started "Put on what you want to haul, but never put on more than you can step with" 3 trucks on a small grade, 1 be struggling, he will get stopped. Because I would often run fat, I would always have my old snot turned up so I could pack a jag, and look right.
And tire slip will limit how much the toad will slow the combination, but most interstate travel, with the MH supplying the power, nothing will be coming out of batteries. But most anytime the rig slows, even to reduce speed to match a slower vehicle while a faster overtakes you, a little of the wasted energy could go in the battery. Would it get the battery from half to full in the course of a day? Don't know. But I would bet my last dollar a ICE has no more gas in the tank than when started at end of day, unless you pumped it there.

"EVs are known to eat up tires in the first place" I did not know this. Any idea as to the why of that?

[valhalla360]

JRscooby wrote:

valhalla360 wrote:


Of course, if only when the MH brakes are hit (and activating the EV brakes)...not much regenerative braking when doing a rural 200mile freeway drive, so really pretty pointless.

To recharge the car so it's has a full battery bank upon arrival, you would need a way to activate the regenerative braking system while the MH is NOT braking and that gets silly pretty quick.

The lowest point in Co is higher than the highest point in Mo, so I 70 WB in Kansas is climbing all day. But still there are more than a few places where I would use the jake to keep my speed close to limit. Bet the MH has to use some kind of whoa just as often. Why couldn't the combination be programed so the first brake to come on when the grade starts to increase the speed is re-gen? Speed still climb, use the jake. If the driver is smart, he is letting off throttle long before he is on the brakes, to save brakes and more important, fuel. Use re-gen to slow more before brakes.

valhalla360 wrote:

Skibane wrote:
The dinghy vehicle could not only be used to brake itself, but could also contribute some braking ability to the motorhome towing it.

There's a lot of kinetic energy in a 30,000 pound motorhome rolling down the road at 75 MPH! :B

Expect to buy tires more frequently if the light duty car tires are used to stop a 30k lb MH.

I don't stand under what you are saying here. You think re-gen would lock the wheels? I think the slower the wheel is turning, the less output to battery. That output is the only braking action

A few minutes braking on the downhills won't add much to the battery pack. Regenerative braking is mostly about recovering the acceleration power used.

I don't recall any long downhills on that stretch...for the most part, you don't even need to touch the brakes to keep speed under control...but let's say you find a 2min stretch of downhill where the regen is putting out 50kw. That's going to generate a whopping 1.6kwh on a car that likely has a 80-120kwh battery bank. Even if you find 10 downhill stretches on the stretch of road you mention, that's only 16kwh. In much of the country, I never have to touch the brakes to keep the speed at the limit.

EVs are known to eat up tires in the first place (without locking up the tires). Trying to meaningfully slow down a 30,000lb MH is only going to accelerate the issue.

[Reisender]

time2roll wrote:

valhalla360 wrote:

Skibane wrote:
The dinghy vehicle could not only be used to brake itself, but could also contribute some braking ability to the motorhome towing it.

There's a lot of kinetic energy in a 30,000 pound motorhome rolling down the road at 75 MPH! :B

Expect to buy tires more frequently if the light duty car tires are used to stop a 30k lb MH.

No more than with the current braking systems.

I don’t know. I kinda see where Valhalla is going. When regen is happening it is like stepping on the brakes fairly firmly. It regenerates at up to 80 KW. (Imagine an 80 kw generator on a trailer behind you :)). If it was only activated on braking sure, but if purposely used for recharging those (expensive) tires are going to wear down quick. Personally I would never charge the car by regeneration, and we towed an EV behind our pusher for 5 years. (Albeit on a trailer soooo).

[free_radical]

Instead of guesing all you have to do is look up

Charging Tesla by towing on YT as others already tried it

And yes it works,however

https://youtu.be/nILM_DEdBqM

[time2roll]

valhalla360 wrote:

Skibane wrote:
The dinghy vehicle could not only be used to brake itself, but could also contribute some braking ability to the motorhome towing it.

There's a lot of kinetic energy in a 30,000 pound motorhome rolling down the road at 75 MPH! :B

Expect to buy tires more frequently if the light duty car tires are used to stop a 30k lb MH.

No more than with the current braking systems.

[Grit_dog]

Ok, based on this thread, everyone who believes in Santa Claus raise your hand…I want to see if I have my list right!

[JRscooby]

valhalla360 wrote:


Of course, if only when the MH brakes are hit (and activating the EV brakes)...not much regenerative braking when doing a rural 200mile freeway drive, so really pretty pointless.

To recharge the car so it's has a full battery bank upon arrival, you would need a way to activate the regenerative braking system while the MH is NOT braking and that gets silly pretty quick.

The lowest point in Co is higher than the highest point in Mo, so I 70 WB in Kansas is climbing all day. But still there are more than a few places where I would use the jake to keep my speed close to limit. Bet the MH has to use some kind of whoa just as often. Why couldn't the combination be programed so the first brake to come on when the grade starts to increase the speed is re-gen? Speed still climb, use the jake. If the driver is smart, he is letting off throttle long before he is on the brakes, to save brakes and more important, fuel. Use re-gen to slow more before brakes.

valhalla360 wrote:

Skibane wrote:
The dinghy vehicle could not only be used to brake itself, but could also contribute some braking ability to the motorhome towing it.

There's a lot of kinetic energy in a 30,000 pound motorhome rolling down the road at 75 MPH! :B

Expect to buy tires more frequently if the light duty car tires are used to stop a 30k lb MH.

I don't stand under what you are saying here. You think re-gen would lock the wheels? I think the slower the wheel is turning, the less output to battery. That output is the only braking action

[valhalla360]

Skibane wrote:
The dinghy vehicle could not only be used to brake itself, but could also contribute some braking ability to the motorhome towing it.

There's a lot of kinetic energy in a 30,000 pound motorhome rolling down the road at 75 MPH! :B

Expect to buy tires more frequently if the light duty car tires are used to stop a 30k lb MH.