2021-2023 cold weather performance fix

[Billyk24]

The pipe insulation photo and thermal camera is interesting but as the author stated: "it is going to be a real pain to wrap all the pipes". A thermal barrier inside the skid plates using simple press and stick adhesive has got to be an easier fix.

Sponsored

 

[GarageWarrior2023]

Interesting ideas and discussion.

I don’t believe, however, there is any chance Ford or any other OEM would create a CSP or TSB to have the insulation installed at Ford/OEM’s expense, absent vehicles actually failing or becoming dangerous to operate because of a lack of insulation.

A potentially more likely scenario is the creation for retail sale of a kit of pre-cut insulation required to do the job. The material would be relatively cheap, the labor would be the killer for those not installing it themselves.

I don’t know the geographical dispersion of these cars, but I would think even if it’s 50% northern tier of the US, Canada, and northern Europe, the market would still be pretty small since a limited number of that cold climate group would feel, literally or figuratively, the need for the insulation. Sounds more like a product for a small, aftermarket, specialty company than an OEM effort.

All that said, it’s a great discussion and interesting idea and may be worth it for some
people well north of the Mason-Dixon Line.

I completely agree with you. It could more likely become a paid "cold/extreme weather kit" offered by Ford. I would be perfectly okay with Ford releasing a paid option rather than covering it with a TSB or CSP.

Obviously the most likely would be a third party creating a kit. But I am hopeful that with some evidence, that Ford could release a kit. It would, I think, be a great option for cold climate customers to option at purchase. Not necessary for mild weather customers, but certainly valuable to cold weather customers. I would look at it much the same way as paying to add a block heater in Canada.

 

[GarageWarrior2023]

The pipe insulation photo and thermal camera is interesting but as the author stated: "it is going to be a real pain to wrap all the pipes". A thermal barrier inside the skid plates using simple press and stick adhesive has got to be an easier fix.

I believe the issue is that cold air enters at the wheel wells and pulls through the entire space under the hood. there's a gap behind the power electronics and everywhere that the heating loops travels. There is also a gap on top of the battery between it and the floor of the interior that channels air along the top and out into the rear end of the vehicle.

I think at speed the air flow/volume increases to a point where the r-value of the hoses is not enough to overcome the -22c and colder air traveling over it in high volumes. The convection cooling effect overcomes the heaters ability to compensate. It's made worse by the fact that the heating loop is so long.

So I don't think insulating that skid plate would do anything, to be honest. That's just my opinion based on what I've tracked and observed so far.

 

[eponey]

So I appreciate that the insulation would deliver more heat to the battery but is this really going to overcome the huge amount of cold air running over the tray and cooling plates?

 

[Billyk24]

So I appreciate that the insulation would deliver more heat to the battery but is this really going to overcome the huge amount of cold air running over the tray and cooling plates?

Do we have any data?

 

[GarageWarrior2023]

So I appreciate that the insulation would deliver more heat to the battery but is this really going to overcome the huge amount of cold air running over the tray and cooling plates?

That's an excellent question and a great observation. I agree.

I had started a post a long time ago where I pushed for recognition that a 2 pronged attack was required for a full solution.
https://www.macheforum.com/site/threads/mach-e-cold-weather-kit-who-wants-one.33781/

While I can't see many arguments against insulating the heating loop of the cabin and battery for proper function and longevity, there seemed to be a split of confidence in insulating the battery....even though other auto makers have done so with no issues.

The mach-e has a liquid cooled battery capable of sub-ambient cooling. Personally I don't think convection cooling of the battery in the summer is a huge part of the equation, especially in bumper to bumper traffic in a place like Florida. I would wager a guess that having a non-thermally conductive bottom cover or an insulated layer would help reduce load on the cooling system in summer and help improve efficiency and function of the heating system in extreme cold climates. But some people are stuck thinking that the bottom of the battery is a radiator that operates the same as the radiator in an ICE vehicle.

I would love to see both components addressed. But there's probably a better chance of the heating loop being insulated than the bottom of the battery unfortunately....

 

[Mach-Lee]

Do we have any data?

I've been tracking my battery pack temperatures in the winter for several years, and have observed it cooling off extremely quickly when there's a combination of both cold weather (<10ºF) AND wind. I've basically parked the car outside in the wind (which was blowing from the side), sat in it, and watched the battery temp tick down at a rate as fast at 1ºC per 5 minutes. That signifies significant convective loss of heat.

When the pack is heated, the bottom of the case warms up quickly and is usually within a few degrees of the cell temps after sitting at rest (viewed with thermal camera). This indicates there is very little thermal isolation between the bottom of the pack and the cold plates, which are sitting probably 1/4" above the bottom of the tray with only an air gap, no insulation. The cells are heatsinked directly to the cold plates, so any heat loss near the cold plates will quickly affect the cells temps.

Same thing when driving, rapid heat loss when there is air blowing under the pack. I don't think the amount of air blowing over the top of the pack is significant, there's only a 1/2" gap or less and the path is convoluted, so there would be a much smaller amount of convection happening over top of the pack compared to underneath. The top of the pack also benefits from heat escaping through the floor of the cabin, if you run cabin heat only for a while the upper stack cell temps on the extended range pack will increase (the ones under the rear seat).

Basically all this points to the bottom of the pack being where the significant heat loss occurs. And from teardowns we know it's not insulated, so it makes sense.

Pack shortly after being heated to above 0ºC, you can see how much heat is leaking out the bottom compared to the surroundings:

 

[eponey]

That's an excellent question and a great observation. I agree.

I mean I'm sure the tubing has some sort of insulated property, you can always insulate more but it's more expensive.

I think the advantages of convection outweigh battery insulation at a large range of temperatures. If you insulated the battery I think you would use a lot of energy in the heating and cooling system as it's a big thermal mass to deal with, so we take advantage of mother nature as much as possible.

 

[GarageWarrior2023]

I've been tracking my battery pack temperatures in the winter for several years, and have observed it cooling off extremely quickly when there's a combination of both cold weather (<10ºF) AND wind. I've basically parked the car outside in the wind (which was blowing from the side), sat in it, and watched the battery temp tick down at a rate as fast at 1ºC per 5 minutes. That signifies significant convective loss of heat.

When the pack is heated, the bottom of the case warms up quickly and is usually within a few degrees of the cell temps after sitting at rest (viewed with thermal camera). This indicates there is very little thermal isolation between the bottom of the pack and the cold plates, which are sitting probably 1/4" above the bottom of the tray with only an air gap, no insulation. The cells are heatsinked directly to the cold plates, so any heat loss near the cold plates will quickly affect the cells temps.

Same thing when driving, rapid heat loss when there is air blowing under the pack. I don't think the amount of air blowing over the top of the pack is significant, there's only a 1/2" gap or less and the path is convoluted, so there would be a much smaller amount of convection happening over top of the pack compared to underneath. The top of the pack also benefits from heat escaping through the floor of the cabin, if you run cabin heat only for a while the upper stack cell temps on the extended range pack will increase (the ones under the rear seat).

Basically all this points to the bottom of the pack being where the significant heat loss occurs. And from teardowns we know it's not insulated, so it makes sense.

Pack shortly after being heated to above 0ºC, you can see how much heat is leaking out the bottom compared to the surroundings:

Yes I've seen the same level of cooling in winter, and a similar effect in summer. Battery is basically always rapidly hitting ambient.

It's frustrating because Ford seems to think this is false data. They're under the impression that this doesn't happen and the battery holds its heat for 8-10 hours in the extreme cold without heating it.

 

[GarageWarrior2023]

I mean I'm sure the tubing has some sort of insulated property, you can always insulate more but it's more expensive.

I think the advantages of convection outweigh battery insulation at a large range of temperatures. If you insulated the battery I think you would use a lot of energy in the heating and cooling system as it's a big thermal mass to deal with, so we take advantage of mother nature as much as possible.

Hey don't take my word for it. Do some digging around. Foundationally, it's best practice to have a thermally non-conductive layer between your battery and the outside environment for best battery protection/longevity and vehicle efficiency. That best practice aside, I won't argue that at temperatures of around or above 20c you do gain some free efficiency if there's no boundary to ambient temperatures. But I will argue that there is a small window of temperatures where air cooling is efficient and safe.

The issue with the Mach-e specifically though, is where they put the cold plates relative to the battery design. Tesla had a woven coolant loop between cylindrical cells. the coolant isn't exposed directly to ambient temperatures. Lucid put the cold plates on the top side of the pack, sandwiched between the battery and the floor of the vehicle.

Because of where the cold plates are, whether you are cooling or heating, you have the most inefficient design possible. It's like trying to heat my garage with the doors wide open or trying to cool my house in summer and leaving all the windows open. So regardless of the intentions, the outcome is a vehicle that's more inefficient.

 

[eponey]

vehicle that's more inefficient.

Makes some sense but for simple operation the battery doesn't have to be micromanaged all that much outside of the extremes.

Maybe you get some gains preparing to fast charge, but that's easier to do when stopped anyways, at the risk it takes longer to charge.

The car fasts charges pretty slow, maybe the added complexity and cost isn't worth it?

 

[GarageWarrior2023]

Makes some sense but for simple operation the battery doesn't have to be micromanaged all that much outside of the extremes.

Maybe you get some gains preparing to fast charge, but that's easier to do when stopped anyways, at the risk it takes longer to charge.

The car fasts charges pretty slow, maybe the added complexity and cost isn't worth it?

Well, I'm pretty confident the battery was supposed to have a thermally non-conductive insulator pad under each cold plate so they could function efficiently. very little added cost or complexity. I believe a later management decision or supply chain issue (products of that nature from 3M and other during the pandemic became back ordered) caused it to be omitted late in pre-production. That's my theory.

As for the heating/cooling loop. Most manufacturers aren't insulating these (but I wish they would), and the rubber does have a low R-value. Where Ford went wrong, was making it unnecessarily long. This added cost, complexity and created an issue with keeping the coolant warm or cool efficiently while traveling through a lengthy maze of thermal loss.

When you look under the hood and think about the routing for a few seconds, you start to wonder how anyone would have approved the design in the first place. It costs more, it's more parts, more hose, more everything. It's not even smart from a manufacturing or cost perspective, let alone function and efficiency.

My simplest take on the Mach-E is "doing less with more".

 

[Peugfan]

They were rushed in getting to market, it works, and they didn't have time to design a $1,600 octavalve.

 

[GarageWarrior2023]

They were rushed in getting to market, it works, and they didn't have time to design a $1,600 octavalve.

Ya, they made a huge mistake pretending to be Tesla.

In a pinch and when rushed, they would have been better served keeping things simple and direct rather than trying to add complexity that took Tesla a decade to perfect.

 

[eponey]

My simplest take on the Mach-E is "doing less with more".

I thought I remembered seeing they took one of their existing cooling systems and just modded it, who knows how true that is.

Sponsored