Anybody tried Emergency Flat-tow w Regen to charge when stuck in the boonies?

Shayne

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Strap towing can be fun. Not sure if it is legal everywhere and understand why due to the past fun. Definitely need safety chains on there somewhere to tug you if it lets go. Hook it up with what? Then what? Then they run into the back of you and get all pissed. Another one that has towed in the past and if asked would smile and walk away. Would be a good story thou. I would test it before trying to find someone when counting on it. Good luck finding someone experienced in towing do it.

Yeah, I have a tow rig. I would never hook up someone I don’t know with an EV to flat tow them to get them power. All it takes is that person hitting the brakes because they’re scared of being 1ft from the back of another vehicle and bye bye tow rig. I’d point to the closest campground or power source and say good luck… maybe bring a portable generator down if I was feeling like I had plenty of time to kill.
Extension cord and drier adapter is where I would go. Drier outlets are all over the place and could be planned if you can not locate a RV park or an electric stove/welder outlet. Lots of the remote areas I look at are tourist locals and have RV parks with electrical services. Takes a bit more planning and leisure time but it could be done with no towing involved.
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Awmustang

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I think your biggest issue will be that the system is designed for regen of going down an actual long hill and not much more than that. We already saw a couple MME's get bricked from going down actual long hills. To get any reasonable juice into the battery you'd have to go "down a long hill" for far longer than is possible in real life so I guarantee the engineers haven't accounted for it in the design.
Will it work, probably. Will it cause damage, maybe not if you are careful. Will it make a meaningful difference, unlikely.
Check this video out. Not a MME but the principles are the same.
 
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dtbaker61

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Strap towing can be fun. Not sure if it is legal everywhere and understand why due to the past fun.
I have 'had' to strap-tow my DIY converted eMiata a couple times for short distances, not because it ran out of Energy, but twice when cheapo dc-dc converters failed and I had no 12v power. Fortunately the eMiata has a manual steering rack, unfortunately the power brakes are N/A without 12v, and it has a DC motor no no Regen... which meant riding the brakes MANUALLY to maintain tension on strap while my wife was driving my old ICE vehicle (a Mazda 3, manual transmission) to tow me 2 miles home.

If my wife can handle a short strap-tow in emergency, I would think that virtually any vehicle COULD give an Emergency tow to the nearest safe place to park/charge.

Extension cord and drier adapter is where I would go. Drier outlets are all over the place and could be planned if you can not locate a RV park or an electric stove/welder outlet. Lots of the remote areas I look at are tourist locals and have RV parks with electrical services. Takes a bit more planning and leisure time but it could be done with no towing involved.
Certainly the goal to have mobile charger with both 120v and 240v 'tails' as well as a stout extension cord (BadAss 10/3)... strap tow would be a LAST RESORT, not a 'Plan' as some seem to have interpreted this thread.

The very real issue in Northern NM is that there are a couple stretches of secondary highways that go thru Natl Forests... and there are stretches with NO houses, restaurants, and campgrounds that close for the Winter. I've plotted my routes, and I *should* be ok. If the temp drops to -5F, or I get down around 5% SOC, I want to have Emergency equipment with me to get to the nearest plug and calling a tow truck may or may not be an option.

so, under my cargo floor, I now have:
- jumper cables (to give or get a 12v jump)
- front tow Bridle
- tow strap

and in the Frunk, when I travel, I have:
- Ford Mobile charger with both tails
- 50' BadAss 10/3 extension cord
 
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dtbaker61

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I think your biggest issue will be that the system is designed for regen of going down an actual long hill and not much more than that. We already saw a couple MME's get bricked from going down actual long hills. To get any reasonable juice into the battery you'd have to go "down a long hill" for far longer than is possible in real life so I guarantee the engineers haven't accounted for it in the design.
Will it work, probably. Will it cause damage, maybe not if you are careful. Will it make a meaningful difference, unlikely.
I would plan on using just enough regen to maintain strap tension, probably somewhere between 20kw-50kw... so as not to bog down tow vehicle and to keep temp of motor/inverter/HVBJB down. I do have a CarScanner custom dashboard I can display this info on to keep an eye on it, so I'm not worried about that part.

The longest stretch I can imagine needing a tow to the nearest plug would be maybe 20 miles tops, which might translate to a half-hour tow.... probably regen no more than 10 kWhr with 'light' tension on strap in that timeframe, but that might be just enough to reach a L2 charger, or a 240v outlet.

The instances of 'bricking' from long downhills and/or DCFC I hope are in our rear-view with the new HVBJB.
 

Awmustang

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I would plan on using just enough regen to maintain strap tension, probably somewhere between 20kw-50kw... so as not to bog down tow vehicle and to keep temp of motor/inverter/HVBJB down. I do have a CarScanner custom dashboard I can display this info on to keep an eye on it, so I'm not worried about that part.

The longest stretch I can imagine needing a tow to the nearest plug would be maybe 20 miles tops, which might translate to a half-hour tow.... probably regen no more than 10 kWhr with 'light' tension on strap in that timeframe, but that might be just enough to reach a L2 charger, or a 240v outlet.

The instances of 'bricking' from long downhills and/or DCFC I hope are in our rear-view with the new HVBJB.
In case you don't have the time to watch the video, they flat towed a Tesla for 3.5 miles before the car started showing errors and disabled regen completely. I'm not a Tesla fan boy but if it only made it that far I'd be shocked if the Ford could go much further while using regen. But as you said, this is a last ditch, no other solutions available, option so it could be worth a short try, but 20 miles seems a bit optimistic.
 


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dtbaker61

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In case you don't have the time to watch the video, they flat towed a Tesla for 3.5 miles before the car started showing errors and disabled regen completely. I'm not a Tesla fan boy but if it only made it that far I'd be shocked if the Ford could go much further while using regen. But as you said, this is a last ditch, no other solutions available, option so it could be worth a short try, but 20 miles seems a bit optimistic.
makes me wonder how many kw of regen they were pulling for those 3.5 miles.... given they got 10% charge... I did not see any instrumentation showing that. If they were 1-p, 0% throttle, it could have been upwards of 100kW, which would be pretty tough on both vehicles.... totally explains the Tesla battery overheating
 
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tannerk89

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Not to throw out the obvious, free tow from Ford to nearest dealer when you run out of charge I s an option, that’s likely way more practical and less likely to damage something than flat towing. If someone is nearby to “flat tow” your car they could give you a ride to cell service to get your car actually towed.

I get you are bent on making this flat tow a viable option, and sounds like you’ve done your planning to not need it.. but please share the full details with pics, vids, and damage report if you end up trying it.
 
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dtbaker61

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Not to throw out the obvious, free tow from Ford to nearest dealer when you run out of charge I s an option, that’s likely way more practical and less likely to damage something than flat towing. If someone is nearby to “flat tow” your car they could give you a ride to cell service to get your car actually towed.

I get you are bent on making this flat tow a viable option, and sounds like you’ve done your planning to not need it.. but please share the full details with pics, vids, and damage report if you end up trying it.

where I will be going, the nearest Dealer is more than a hundred miles away. The nearest L3 charger would also be more than 100 away.... nearest house (with 120v) might be 50, and nearest business with a 240v outlet or L2 charger would also be 50 miles away.

hence, my research and hesitation to depend on a timely Towtruck to arrive with Flatbed
 
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dtbaker61

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HutchRed

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I can build better than that myself.... but any meaningful amount of watts of solar panel won't fit in the MME. I cannot use my entire cargo area for a bunch of modules and an inverter I would hope NOT to need. That would be like packing a gasoline or propane generator. ;)
lol, yeah, I know. I was just messing around.
 

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Did you ever test this?

Random guess, but I wonder if it would work best to start regen-pulling when you still have some 10%-ish battery left so you can push a bit of power from the battery to the motors from time-to-time so the car believes you're actually driving it and not towing it.

When we used to flat tow at the ranch, we would run the tow strap through a length of pipe that would hang between the vehicles such that there could never be less than a certain amount of tension on the strap. This provided braking and kept tension on the strap at all times, even when stopped. This worked well on vehicles with high clearance and a decent front bumper so the pipe could hang under the towed vehicle if it got too close to the tow vehicle. I'm not sure it would work with the location of the winch keyholes on the Mustang.
 
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dtbaker61

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Did you ever test this?

Random guess, but I wonder if it would work best to start regen-pulling when you still have some 10%-ish battery left so you can push a bit of power from the battery to the motors from time-to-time so the car believes you're actually driving it and not towing it.

When we used to flat tow at the ranch, we would run the tow strap through a length of pipe that would hang between the vehicles such that there could never be less than a certain amount of tension on the strap. This provided braking and kept tension on the strap at all times, even when stopped. This worked well on vehicles with high clearance and a decent front bumper so the pipe could hang under the towed vehicle if it got too close to the tow vehicle. I'm not sure it would work with the location of the winch keyholes on the Mustang.

I would guess that it would be best to:
- be in contact phone contact with tow vehicle
- have ODB2 and CarScanner in MME so that you can monitor actual kW regen 'realtime'
- use 1-p and manually adjust MME regen with partial throttle to pull no more than 50kw regen to limit the load on tow vehicle and maintain reasonable tension on towstrap

I would NOT suggest 0% throttle, which would result in 100kw regen.... be a hard tow, and heat up battery like a DCFC.
 

AKgrampy

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I would guess that it would be best to:
- be in contact phone contact with tow vehicle
- have ODB2 and CarScanner in MME so that you can monitor actual kW regen 'realtime'
- use 1-p and manually adjust MME regen with partial throttle to pull no more than 50kw regen to limit the load on tow vehicle and maintain reasonable tension on towstrap

I would NOT suggest 0% throttle, which would result in 100kw regen.... be a hard tow, and heat up battery like a DCFC.
But did you ever test it? Just curious.
 
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dtbaker61

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But did you ever test it? Just curious.
no, I have not tested..... just a matter of time and arranging an afternoon with a buddy that has a truck with a hitch to tow me around the block.
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