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]

Skibane wrote:

valhalla360 wrote:
Charging via towing would likely cost far more than paying for grid power. The MH would burn significant extra fuel to drag a car that is resisting being pulled.

The OP asked about using regenerative braking, which only produces drag when the brakes are applied.

OP wasn't particularly clear on that point.

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.

[way2roll]

FWC wrote:

Skibane wrote:

FWC wrote:
With auto driving also on the radar, what about not even connecting the car to the MH? It just follows along 5m behind the MH as if it were towed? No hooking up, no disconnecting, no extra length or weight on hills. With some sort of beacon on the MH for the car to follow, this seems like a much easier control problem than 'normal' auto pilot for an EV.

A true self-driving vehicle wouldn't even need to stay behind the motorhome - just program in the desired destination, and the vehicle would get there on its own.

Naturally, due to range limitations, it might need to meet you at designated charging stations along the way.

Agreed, with true self driving there would be no need to follow along.

My thought is that a follow on mode would be much easier to achieve than full self driving and gets away from some of the murky legal and liability issues with self driving vehicles. The technical challenges are far easier - just follow the huge MH in front of you and from a legal/liability issue the EV could be treated just the same way a towed vehicle.

If it's truly self driving and you miss your payments, does it drive itself back to the dealership? 🙂

[philh]

ktmrfs wrote:
when we were looking at hybrids NONE that we looked at (both mild hybrids and plug ins) allowed 4 down towing. ALL made it very clear that the car MUST be flatbed towed. Now we didn't look at all but we did look at many.

Ford Hybrids are flat tow capable.

[FWC]

Skibane wrote:

FWC wrote:
With auto driving also on the radar, what about not even connecting the car to the MH? It just follows along 5m behind the MH as if it were towed? No hooking up, no disconnecting, no extra length or weight on hills. With some sort of beacon on the MH for the car to follow, this seems like a much easier control problem than 'normal' auto pilot for an EV.

A true self-driving vehicle wouldn't even need to stay behind the motorhome - just program in the desired destination, and the vehicle would get there on its own.

Naturally, due to range limitations, it might need to meet you at designated charging stations along the way.

Agreed, with true self driving there would be no need to follow along.

My thought is that a follow on mode would be much easier to achieve than full self driving and gets away from some of the murky legal and liability issues with self driving vehicles. The technical challenges are far easier - just follow the huge MH in front of you and from a legal/liability issue the EV could be treated just the same way a towed vehicle.

[Skibane]

FWC wrote:
With auto driving also on the radar, what about not even connecting the car to the MH? It just follows along 5m behind the MH as if it were towed? No hooking up, no disconnecting, no extra length or weight on hills. With some sort of beacon on the MH for the car to follow, this seems like a much easier control problem than 'normal' auto pilot for an EV.

A true self-driving vehicle wouldn't even need to stay behind the motorhome - just program in the desired destination, and the vehicle would get there on its own.

Naturally, due to range limitations, it might need to meet you at designated charging stations along the way.

[Durb]

With all the technology designed into battery electric vehicles, I'm guessing that designing software to make them push/pull on demand would be easy-peasy on their complexity scale.

[mike-uswest]

Reisender wrote:

mike-uswest wrote:
Well,going to a recent back post, I looked up BEV and BEV/RV on google to no avail. I guess I'm just too old to know what people are talking about anymore.

Mike

Good morning. A BEV is a battery electric vehicle.

Thank you.

[Reisender]

JRscooby wrote:

Reisender wrote:

Any EV we have owned has had a neutral position. So free spin down the road with no regen. Putting it back in drive immediately engages regen.

I could well be wrong, but I assumed the neutral position was just dis-connect the motor electrically. Are you saying that there is a mechanical dis-connect between wheel and motor? If so, that would mean even less friction than I thought.(But more moving parts than I expected)

Durb wrote:

JRscooby wrote:
Now to get into the most interesting idea. Some new vehicles can follow at a certain distance. Why couldn't things be wired so when MH is full throttle, power is turned on, so the toad pulls it's own weight? Or even push the MH some?

Wow, never considered this. Potential exists to use regenerative braking to help slow the MH and applying the juice to help push the MH when needed. Essentially, the BEV toad would be turning the DP into a hybrid.

Not sure you could get enough push to call it hybrid. Tire slip would be a issue. But I have read about people unhooking toad, driving separate on steep uphills. A self propelled toad would eliminate the need for that. Drafting that close behind MH, would go a long ways before pulled enough out of battery to have re-gen on the downside. But pushing the MH would discharge battery fast, so regen could help the jake, keep service brakes cool incase needed.

Re the neutral question. I don’t know. I just know if I select neutral it is like selecting neutral in our old Grand Cherokee. It just rolls. What’s happening on the mechanical side is out of my area of exercise. We use it every time we go thru a car wash.

[JRscooby]

Reisender wrote:

Any EV we have owned has had a neutral position. So free spin down the road with no regen. Putting it back in drive immediately engages regen.

I could well be wrong, but I assumed the neutral position was just dis-connect the motor electrically. Are you saying that there is a mechanical dis-connect between wheel and motor? If so, that would mean even less friction than I thought.(But more moving parts than I expected)

Durb wrote:

JRscooby wrote:
Now to get into the most interesting idea. Some new vehicles can follow at a certain distance. Why couldn't things be wired so when MH is full throttle, power is turned on, so the toad pulls it's own weight? Or even push the MH some?

Wow, never considered this. Potential exists to use regenerative braking to help slow the MH and applying the juice to help push the MH when needed. Essentially, the BEV toad would be turning the DP into a hybrid.

Not sure you could get enough push to call it hybrid. Tire slip would be a issue. But I have read about people unhooking toad, driving separate on steep uphills. A self propelled toad would eliminate the need for that. Drafting that close behind MH, would go a long ways before pulled enough out of battery to have re-gen on the downside. But pushing the MH would discharge battery fast, so regen could help the jake, keep service brakes cool incase needed.

[Reisender]

mike-uswest wrote:
Well,going to a recent back post, I looked up BEV and BEV/RV on google to no avail. I guess I'm just too old to know what people are talking about anymore.

Mike

Good morning. A BEV is a battery electric vehicle.

[mike-uswest]

Well,going to a recent back post, I looked up BEV and BEV/RV on google to no avail. I guess I'm just too old to know what people are talking about anymore.

Mike

[FWC]

With auto driving also on the radar, what about not even connecting the car to the MH? It just follows along 5m behind the MH as if it were towed? No hooking up, no disconnecting, no extra length or weight on hills. With some sort of beacon on the MH for the car to follow, this seems like a much easier control problem than 'normal' auto pilot for an EV.

[Durb]

JRscooby wrote:
Now to get into the most interesting idea. Some new vehicles can follow at a certain distance. Why couldn't things be wired so when MH is full throttle, power is turned on, so the toad pulls it's own weight? Or even push the MH some?

Wow, never considered this. Potential exists to use regenerative braking to help slow the MH and applying the juice to help push the MH when needed. Essentially, the BEV toad would be turning the DP into a hybrid.

[Reisender]

JRscooby wrote:
I will never have a MH or EV but I would like to see discussion of this. So far, the only reason I have seen why it can't be done is Manufacturer does not recommend.
(Years back, friend bought brand new Mack. I was picking him up at dealer, he told service manager the 460 HP would not keep up with my old 425 Cat, Turn it up! "But Roger, it is set as hot as we can and still have a warranty" DU*K THE WARRANTY! I'M NOT SPENDING THIS MUCH TO BE PASSED!) On the keyboard, do we need to worry about warranty?
E cars don't have neutral. If we can keep the parking brake disengaged, that is not a issue, IMHO. Electrically disconnected, a motor can spin with no more harm than running at the same speed. Extra friction? Most toads now in use are 4X4. So when towing you are spinning axles, differentials and driveshafts. And there is more friction ring/pinion when driving the ring instead of pinion. So I can't see a big friction increase spinning the motors.
Braking; I assume EV has a braking system that works pretty much like any other toad. So any system to apply brakes on toad can be adapted to EV. Also, I can't see how it would be real hard to control regen from MH. And holding the weight of both vehicles back on a downhill could put a lot of power in battery. But once full charge that whoa is gone.
Now to get into the most interesting idea. Some new vehicles can follow at a certain distance. Why couldn't things be wired so when MH is full throttle, power is turned on, so the toad pulls it's own weight? Or even push the MH some?

Any EV we have owned has had a neutral position. So free spin down the road with no regen. Putting it back in drive immediately engages regen.

[JRscooby]

I will never have a MH or EV but I would like to see discussion of this. So far, the only reason I have seen why it can't be done is Manufacturer does not recommend.
(Years back, friend bought brand new Mack. I was picking him up at dealer, he told service manager the 460 HP would not keep up with my old 425 Cat, Turn it up! "But Roger, it is set as hot as we can and still have a warranty" DU*K THE WARRANTY! I'M NOT SPENDING THIS MUCH TO BE PASSED!) On the keyboard, do we need to worry about warranty?
E cars don't have neutral. If we can keep the parking brake disengaged, that is not a issue, IMHO. Electrically disconnected, a motor can spin with no more harm than running at the same speed. Extra friction? Most toads now in use are 4X4. So when towing you are spinning axles, differentials and driveshafts. And there is more friction ring/pinion when driving the ring instead of pinion. So I can't see a big friction increase spinning the motors.
Braking; I assume EV has a braking system that works pretty much like any other toad. So any system to apply brakes on toad can be adapted to EV. Also, I can't see how it would be real hard to control regen from MH. And holding the weight of both vehicles back on a downhill could put a lot of power in battery. But once full charge that whoa is gone.
Now to get into the most interesting idea. Some new vehicles can follow at a certain distance. Why couldn't things be wired so when MH is full throttle, power is turned on, so the toad pulls it's own weight? Or even push the MH some?