Tow/Haul, Max Tow, and Hot Weather Road Trips

[topher10]

I’m planning a late-July trip from Baton Rouge to Key Largo, which will require several DC fast-charging stops in 90+ temps. My 2024 Flash has the Max Trailer Tow Package, but I will not be towing. I did a similar trip last year, and the battery would often heat up during DCFC stops. My simple question is whether there is any consensus on whether I should periodically run the truck in Tow/Haul mode to aid battery cooling, particularly before or after the DCFC.

I have done some searching on this topic, including the discussion showing that Tow/Haul mode can bring an elevated battery-temperature indication back toward the midpoint much faster:
https://www.f150lightningforum.com/...perature-faster-using-tow-haul-mode-🌡️.21558/

I’m trying to separate two different things:
1. Does the Max Tow package’s additional cooling hardware operate automatically whenever the truck needs it, regardless of drive mode?

2. When Tow/Haul is selected without a trailer, does it: A) actually activate additional cooling hardware, B) make the software request more aggressive cooling, or C) make no practical difference because the truck protects itself (Question #1).

I’m especially interested in observations from owners who have:
- Compared Normal and Tow/Haul in similar ambient temperatures
- Monitored actual battery or coolant temperatures through OBD data
- Tested immediately before or after consecutive DCFC sessions
- Compared Max Tow and non-Max Tow trucks
- Noticed a measurable efficiency penalty
- Seen differences by model year or software version

I hope this is not beating a dead horse, but I would appreciate your thoughts/advice. I could also use this trip to run some experiments of my own.

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[B177y]

There was another recent thread asking something similar, but I don't remember the exact circumstances. Forum member @RLXXI who I believe is a current mechanic had an answer of (paraphrasing from memory) "If the temp gauge is in between the brackets its OK". The brackets are almost the entire temp gauge. I'm sure he'll give his answer now that I tagged him.

From my experience, I have seen my battery temp go over 100 deg F during a road trip with multiple DCFC measured by Carscanner. The temp gauge was slightly right of center. I have a max-tow but was not in tow mode and not towing at the time, but I was hauling quite a bit of gear in the bed and frunk. The truck took care of itself and cooled the HVB into the high 70's - low 80's F by the time I got to the next DCFC. The temp gauge in the truck quickly returned to center on it's own. From what I saw, that dead-center mark of the gauge has quite a large range of "happy temperature" before moving to the low or high side. I have only seen the gauge go slightly to the low side when my HVB showed a temp in the mid 30's F on Carscanner, and that quickly came to center as well after a short drive.

Bottom line, as long as your cooling system is working and the coolant level is correct, I wouldn't worry about the temp at all.

I used to run Carscanner and ABRP live data while driving road trips all the time. Now after learning and watching the truck behavior and temperatures, I drive it and don't worry. Over 55,000 miles on my 2024.

 

[K6CCC]

I somewhat regularly see the battery temp above the center spot after DCFC in hot weather. Two days ago I did an only 14 minute charge in 105 degree weather and the battery temp was about 3/16" to the right of center. Putting the truck in Tow/Haul mode (even without the Max Tow Package) speeds up cooling the battery back down.

 

[RocketGhost]

Max tow gives you a separate cooling system (compressor, heat exchanger) for just the battery and motors. Non-max tow it's only one for the cabin too.

The truck will manage the battery temperature and won't let it overheat. It will slow down or even stop charging if it has to.

You could try some preconditioning tricks that may speed up fast charging but likely not enough to really matter.

 

[TaxmanHog]

Max tow gives you a separate cooling system (compressor, heat exchanger) for just the battery and motors. Non-max tow it's only one for the cabin too.

The truck will manage the battery temperature and won't let it overheat. It will slow down or even stop charging if it has to.

You could try some preconditioning tricks that may speed up fast charging but likely not enough to really matter.

THIS

Max-tow system is dedicated to the drive train, thermal is being managed well with the dedicated system, switching drive modes has more impact on handling, throttle and braking.

 

[Vulnox]

We did a road trip at the start of June and on the way back temps were up there and DCFC put the temp above the middle by a decent amount. I just got back on the highway and drove and it came back down over the next 20 minutes or so back to the middle.

I have a strong aversion to doing things like Tow/Haul mode just because you see a temp bar move from the absolute center. We complain about how much of a nanny modern vehicles are but think they won't yell at us if they are overheating or whatever, or that it won't utilize the same capabilities as tow/haul mode on its own if it is needed. And Ford has always been super conservative on how far they let things run out of spec, so if it was important to the health of the truck they would be throwing those warnings for sure.

All that is to say, I don't think it's bad or harmful if you want to kick in extra cooling because it makes you feel better, it's your vehicle ultimately! But I don't like it getting around like the Lightning is a delicate flower and you have to do all this work to keep it cool because it won't do it itself. It absolutely will, and if it does ever hit a point where it's struggling it will definitely let you know.

 

[DavidS]

I don’t have Max Tow but my general strategy recommendations are start off with charging the day or night before, hitting a DC charger at the start of your road trip puts you in a thermal hole right from the start, and, if possible, pick routes with higher road speeds. My experience is that in bumper to bumper beach traffic in hot weather, the Lightning can struggle to cool down between charging sessions and then de-rate charging.

 

[hturnerfamily]

we've driven this amazing machine over 71,000 miles, and over 25,000 while towing one of various size and weight campers, as well as a few utility trailers...and in Sport Mode', Normal Mode', and even Tow mode', although I've never used a specific mode simply because I thought it would lower the temp of the battery, or somehow better 'pre-condition' the battery, etc....

the truck already knows how to control these things... MaxTow may give a separate chiller/compressor to the battery pack, yes, but that is in play no matter what Mode' you choose...

Modes are about the regeneration level, and that's it - they don't 'give' more power, provider 'better' towing', or somehow change the characteristics of the vehicle...(there may be some noticeable play in the power pedal, but that's not a 'change' of power, but simply how quickly the pedal triggers power)
... so it's really only about what Mode' type you like to drive in... Sport will be the FIRMEST Regen, TowMode in the middle, and a little with Normal...

I've driven with any modes with our campers, and it makes no difference, other than what you 'like'...

 

[fhteagle]

I would be more concerned with the temperature of the CCS inlet. This is especially true if you are using a NACS adapter, even a UL2252 rated one. Mine is rated, and still gave me a very slight burn after charging in El Paso in 104F and full sun. Cannot put the adapter back in its case for a good 15+ minutes after a session.

Tesla says no wet rag trick any more, but in these conditions I would at least use a wet rag for the disconnect process...

 

[K6CCC]

Tesla says no wet rag trick any more, but in these conditions I would at least use a wet rag for the disconnect process...

Leave a pair of light gloves in the truck. Works great for the purpose.

 

[astrand1]

I would be more concerned with the temperature of the CCS inlet. This is especially true if you are using a NACS adapter, even a UL2252 rated one. Mine is rated, and still gave me a very slight burn after charging in El Paso in 104F and full sun. Cannot put the adapter back in its case for a good 15+ minutes after a session.

Tesla says no wet rag trick any more, but in these conditions I would at least use a wet rag for the disconnect process...

I have the A2Z adapter and charging in over 100F temps I’ve never been burned by it. Yes it gets a little toasty but it’s never been that hot.

 

[21st Century Truck]

I just drive it like I stole it a habit which might, just might be reflected by a failed front motor bearing (separate thread).

 

[fhteagle]

I have the A2Z adapter and charging in over 100F temps I’ve never been burned by it. Yes it gets a little toasty but it’s never been that hot.

The problem with the one I have is the CCS release latch on top is black metal. Even while not charging it gets very hot in the sun. It was a very light "burn" that it gave me that one time, just enough to cause pain and a bit of altered sensation in my thumb for awhile. No blistering or anything like that. Rest of the plastic housing gets hot but you can still hold it. Its just that metal CCS release latch that is the major problem with mine.

Reason number 42 why I am glad CCS Type 1 is on its way out.

 

[astrand1]

The problem with the one I have is the CCS release latch on top is black metal. Even while not charging it gets very hot in the sun. It was a very light "burn" that it gave me that one time, just enough to cause pain and a bit of altered sensation in my thumb for awhile. No blistering or anything like that. Rest of the plastic housing gets hot but you can still hold it. Its just that metal CCS release latch that is the major problem with mine.

Reason number 42 why I am glad CCS Type 1 is on its way out.

Yes! I wish we could retrofit a Mac’s plug on our trucks. I know it’s not possible but how cool would it be if we could. One can dream. lol.

 

[jamelski]

It will cool on its own but if you want it to get back to middle of the battery temp gauge faster put it in sport &or tow mode and it will cool it back to middle faster than normal mode

it just uses more juice to cool it no reason too IMO. Just gonna have to charge sooner

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