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Does LIBCM have access to the cabin temperature sensor or is it just using that green wire? I asked because it seems like I need to warm up the car for 20+ minutes before the battery fan will turn on.

It seems like it would be best just to have the fan turn on whenever the car is on and the battery is below 7 to 8° C. The battery heats up pretty quick once the fan turns on.

I'm still noticing that the battery will slowly deplete if I leave it on idle while the battery is super cold. You are probably right about the power going to the IMA but I don't understand why. I am running it on defrost with an aftermarket AC compressor. I basically need to run the AC all the time to try to dry out the cabin because I'm still having a wet floor mat water leak on the driver side.

You should get some good first hand data when you drive up to Madison.

I'm using the latest official firmware release, should I move to the pre release?
 

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Discussion Starter · #62 ·
@mudder
Great video, makes me wish i had heated seats and a remote starter. ONLY KIDDING. all i can say is your a stand up kind of guy. can't believe your going above and beyond with this challenge. Have a Happy Thanksgiving in Wisconsin. while your there you should ask the fam what type of heat source they use, and ask them if they have redundancy.. 'back up' heat,, and how much Insulation do they have.. so if plan A fails and plan B fails.. how much time do they have to call tech before calling a plumber.
Kidding Aside, Have a Happy Thanksgiving.

my only thoughts;
the photo eye in the motion light on the front of my garage only lasted two years this last time sigh
as a matter of fact that brings up another issue. the ceiling inside the garage has round porcelain receptacles for incandescents. i switched em all to ecosmart home depot bulbs, there cheap china led's but i have had five of those burn out in the last two years also. i dont know if its a switching on and off in the cold thing but the ones i replaced in the house are still goin on strong. its just my typical luck
 

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Discussion Starter · #63 ·
Does LIBCM have access to the cabin temperature sensor or is it just using that green wire? I asked because it seems like I need to warm up the car for 20+ minutes before the battery fan will turn on.

It seems like it would be best just to have the fan turn on whenever the car is on and the battery is below 7 to 8° C. The battery heats up pretty quick once the fan turns on.

I'm still noticing that the battery will slowly deplete if I leave it on idle while the battery is super cold. You are probably right about the power going to the IMA but I don't understand why. I am running it on defrost with an aftermarket AC compressor. I basically need to run the AC all the time to try to dry out the cabin because I'm still having a wet floor mat water leak on the driver side.

You should get some good first hand data when you drive up to Madison.

I'm using the latest official firmware release, should I move to the pre release?
DISCLAIMER 'DONT DO WHAT I DO'
ive owned so many vehicles without a/c and if you cant get the floor dry you may have to resort to letting the snow freeze solid on the carpet. i'm not joking. just wear wool socks and run the upper defroster, cycle the windows to let the steam out. try to kick as much off of your feet every single time you get in your car. get a deep dish floor mat that you can empty out as needed. my a/c doesn't work in my car and i just dress warmer, use lots of layers and crack the windows to let the steam out. good luck
 

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Does LIBCM have access to the cabin temperature sensor or is it just using that green wire? I asked because it seems like I need to warm up the car for 20+ minutes before the battery fan will turn on.
Green wire only.

It seems like it would be best just to have the fan turn on whenever the car is on and the battery is below 7 to 8° C. The battery heats up pretty quick once the fan turns on.
Good idea. I've added a note to do this. I'll add the same behavior when the battery is hot, too (i.e. in the summer).

I'm still noticing that the battery will slowly deplete if I leave it on idle while the battery is super cold. You are probably right about the power going to the IMA but I don't understand why. I am running it on defrost with an aftermarket AC compressor. I basically need to run the AC all the time to try to dry out the cabin because I'm still having a wet floor mat water leak on the driver side.
DCDC can't output enough current at idle unless the IMA battery provides supplemental power. In other words, this is expected behavior.

I'm using the latest official firmware release, should I move to the pre release?
Pre-release isn't as thoroughly tested (yet), but does have several improvements. I need to get it all in the official (i.e. 'main') release soon... keep coming up with other things to work on.
 

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The area behind the seats where the green thermostat is seems to stay cold unless the fan is running. It is not inaccurate place to measure the cabin air temperature. It seems like the fan only turned on twice in the last week. Today I had to run the car for over 30 minutes with the heat blasting at 90 and the fabric cover pull down / vent cover open.

You could run the fan every once in a while to sample the cabin air temperature.

Thanks for explaining about the DC to DC converter, it makes sense that electricity is required for spark. I'm not sure what the minimum amount of power that could be obtained from the IMA motor. I assume it's possible to run the DC to DC converter and the 75 watt heater from the IMA motor to bypass the battery when it reaches freezing since that's what you were talking about doing with the forced hot air heater.

I'd like to sign up for the beta heating PCB if there is a slot left.

For the FoMoCo system we should be able to put the heater under on the bottomside of the IMA compartment. I believe there is access near where the spare tire goes. We should also add flame proof insulation in that area, including the the other side of the heater. Yes that aluminum area will become a thermal bridge but It's not very thick so as long as we insulate the big flat surface below the battery then it shouldn't be much of an issue.
 

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DISCLAIMER 'DONT DO WHAT I DO'
ive owned so many vehicles without a/c and if you cant get the floor dry you may have to resort to letting the snow freeze solid on the carpet. i'm not joking. just wear wool socks and run the upper defroster, cycle the windows to let the steam out. try to kick as much off of your feet every single time you get in your car. get a deep dish floor mat that you can empty out as needed. my a/c doesn't work in my car and i just dress warmer, use lots of layers and crack the windows to let the steam out. good luck
Yeah the floor area is frozen much of the winter. Still I like to try to keep up with the humidity in the air as it causes condensation. We also get moisture in the cabin from snow melting off our shoes. Opening up the windows can help sometimes but my girlfriend is not a fan of the cold.

@mudder we talked about this somewhat before but you're still that sure I'm not going to have issues blowing hot humid air on the cold battery right?
 

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Okay so I had some difficulties trying to warm up the IMA battery the second time today. I came out a few hours after Jackie used the car and it was at 0° C. I started the engine and left for a long time while I searched around for seat covers online. 50 sum minutes later, I came back at with low SOC and the battery was still at 0°. It was a troublesome situation because I didn't want to run the SOC down and I didn't know how to get the battery temperature up. I ended up driving a mile to the grocery store with the IMA off. The whole time I was thinking where could I buy a battery operated fan at 11:00 p.m. in the middle of winter. I parked, turned the car off, turned back on the IMA and started manually wafting air through the vent... Holy crap! It worked, I was able to push enough heat to the temperature sensor to show a delta. The fan started working, I turned on the car and LIBCM on the showed to 2° C instantly. The temperature change was far too quick to be accurate. I believe the air warmed up the sensor before the batteries. I have been running the car for 10 minutes now with the IMA fan on and the temperature has been at 4 to 5° C for most of the time and it just went up to 6° C. The SOC is still very low, 25% at the moment. I'm going to start forcing a regen. Hopefully the battery is indeed hot enough.

So far I am still having fun with LiBCM. I am not worried because I am confident that mudder will be able to fix the issues that I'm experiencing with his next code update. For now, it's a fun challenge.

I must be setting a record for the worst gas mileage in an Honda Insight. For his last gallon plus I'm basically getting Hummer mileage.

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Okay so I had some difficulties trying to warm up the IMA battery the second time today. I came out a few hours after Jackie used the car and it was at 0° C. I started the engine and left for a long time while I searched around for seat covers online. 50 sum minutes later, I came back at with low SOC and the battery was still at 0°. It was a troublesome situation because I didn't want to run the SOC down and I didn't know how to get the battery temperature up. I ended up driving a mile to the grocery store with the IMA off.
Perhaps I'ved missed something about your own situation, but do you have a Calpod switch? Yesterday afternoon when I left work, I got in the car, turned my key to the first position so that the 4x20 LCD would turn on. It showed my battery at -1° C. So, I flipped on my Calpod switch, and started the car. I started my commute home. Once the coolant warmed up, and I cranked up the heat and within 10 minutes my battery was at +1° C. No fuel economy hit suffered.

The car doesn't generate a lot of heat at idle. IMHO, you are better off driving the car with Calpod enabled than letting it try to warm up at idle. If I didn't have a Calpod switch, that would be a priority install for me.

-Bryan
 
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Discussion Starter · #69 · (Edited)
I must be setting a record for the worst gas mileage in an Honda Insight. For his last gallon plus I'm basically getting Hummer mileage.
your not setting records. im lucky to get 4 mpg when im snowplowing driveways with my fullsize blazer. it may take a few days of preplanned preheating to get it back up but take joeaax1j's advice.

SLIGHTLY OFF TOPIC:
my last tank in my insight I had to drive 60 miles home on 2cylinders. I had an ignition coil burn out on me. Also on that tank I let my car idle A LOT, had 430miles/9.4Gal. A respectable 45 mpg considering what she had to go through. If anyone wants to know.. yes your car will still get you home if you have a coil burn out. i was surprised the car still went the speed limit but if you want to avoid driving in 2 cyl mode, than buy a spare coil and always carry a 10mm wrench in the storage compartment. you might have to cuss a little bit to get the connector off of the coil if its really cold outside. I suppose i'll tell you how to diagnosed this. i was driving when it occured so it was obvious that it was missfiring. the check engine light started flashing which is also an indicator for a steady missfire. it will sound like its running rough and you'll have very low power, if your ima works, it will give your ima a workout with assist. If you have a spare coil, like i do now, you can find a safe place to pull over, leave it idling, take a guess which one. you have a 33.3334% chance you will get it right, OR unplug an injector.. if it dies/stumbles that means you unplugged a running cylinder. try again. You can try spitting on the exhaust manifolds to see which one is dead but the one piece manifold makes this difficult, you'll need a lot of spit, use a small amount of snow if its available. Parts stores do not have our coils in stock, fortunately i have a donor '01MT in the back yard. If you live where hypothermia kills people every year than i recommend you learn how to work on your own car. There's no such thing as uber up here and your lucky to have cellphone signal. Not much traffic at night either.
 

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Perhaps I'ved missed something about your own situation, but do you have a Calpod switch? Yesterday afternoon when I left work, I got in the car, turned my key to the first position so that the 4x20 LCD would turn on. It showed my battery at -1° C. So, I flipped on my Calpod switch, and started the car. I started my commute home. Once the coolant warmed up, and I cranked up the heat and within 10 minutes my battery was at +1° C. No fuel economy hit suffered.

The car doesn't generate a lot of heat at idle. IMHO, you are better off driving the car with Calpod enabled than letting it try to warm up at idle. If I didn't have a Calpod switch, that would be a priority install for me.

-Bryan
I haven't yet installed a Calpod in Jacqueline's car. It's on my to do list. She doesn't like all the buttons and hacks that much. The FAS system in my car scares the crap out of her.

Either way, I need to warm up the car so we can drive safely without the windows fogging up. The car warms up fine at idle. This is what we have been doing every winter for the last 8 years of insight ownership.

Even with the calpod I would have had troubles. The cabin was warm. The reason why my battery stayed at 0° C for an hour yesterday with the car on is because there is very little heat transfer to the battery when the fan is off. At least not enough to counteract the heat loss to the negative -8° C outside weather. Clearly I won't have this problem when Mudder updates the code as we discussed. Running the fan when the battery is cold and the car is on will 100% make it easy for me to warm up the battery before driving.
 
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@mudder we talked about this somewhat before but you're still that sure I'm not going to have issues blowing hot humid air on the cold battery right?
IIRC the lowest RH part on the entire rig is 95% noncondensing. The board has a conformal coating, so that will keep the LiBCM PCB itself in good shape. Each modules' steel exterior might oxidize faster.... not the end of the world.

...

Okay so I had some difficulties trying to warm up the IMA battery the second time today.
battery was still at 0°.
Reminder 0 degC isn't the end of the world for storage, as long as you don't regen at all, and minimize assist. The battery can be stored down to - 30 degC, albeit with shorter overall lifetime. I'm not certain it makes sense to keep warming the battery up by idling.

It was a troublesome situation because I didn't want to run the SOC down and I didn't know how to get the battery temperature up.
SoC is always going to drop while idling. Again, the DCDC cannot source enough power from the engine when idling, because the IMA motor's output voltage is proportional to RPM (and at idle it's too low to run the DCDC above a certain output power).

started manually wafting air through the vent... Holy crap! It worked, I was able to push enough heat to the temperature sensor to show a delta. The fan started working, I turned on the car and LIBCM on the showed to 2° C instantly. The temperature change was far too quick to be accurate. I believe the air warmed up the sensor before the batteries. I have been running the car for 10 minutes now with the IMA fan on and the temperature has been at 4 to 5° C for most of the time and it just went up to 6° C.
I will add this "periodic fan activation to check temperature" feature to the next firmware version. Ideally I'll get it in prerelease before my trip to Madison on Tuesday.

So far I am still having fun with LiBCM. I am not worried because I am confident that mudder will be able to fix the issues that I'm experiencing with his next code update. For now, it's a fun challenge.
The battery heater PCBs I just ordered should probably solve this problem, as long as you can plug the car into an outlet overnight (or drive the car for a few hours each day).

I must be setting a record for the worst gas mileage in an Honda Insight. For his last gallon plus I'm basically getting Hummer mileage.
Pretty bad... but Sawbite's lifetime mileage was something like 5 MPG when I first got it. I believe I got it up to 7 MPG after driving it half a mile.
 

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SoC is always going to drop while idling. Again, the DCDC cannot source enough power from the engine when idling, because the IMA motor's output voltage is proportional to RPM (and at idle it's too low to run the DCDC above a certain output power).
That's weird because the car is able to regenerate at idle during the initial calibration of a new Ima battery or when you pull the number 15 fuse. I do think it increases the throttle of idle during this regeneration. A higher idle would be better for defrosting the windows and might be better for the car.

My fear the other day was that if the fan did not turn on that I would not be able charge the IMA while the car was hot and I would go into the next day with a cold car and insufficient soc to maintain the DC/DC converter during warm up. I know there would have been worked around but this was a lot easier. It turns out wafting warn cabin air with my hand is surprisingly effective for creating a delta that will trigger the battery fan.

Oh, I noticed today that the metal IMA Bay tray is ribbed. It looks like there is a room underneath the tray between the ribs where you could push in long thin resistive heaters for the FoMoCo batteries.

It might be possible to use a gas tank heater and let the tank warm the battery. I'm not sure how energy efficient this would be, how easy it is to install gas tank heaters, or if we can insulate the gas tank. However google says that many types of tank heaters do exist.
 

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That's weird because the car is able to regenerate at idle during the initial calibration of a new Ima battery or when you pull the number 15 fuse.
A 48S LiBCM pack operates ~50 volts higher than OEM. When the IMA motor's output voltage drops below the lithium pack voltage, it becomes very difficult to charge the battery... it's like pushing water uphill. There are some clever math tricks you can do with three-phase power to charge when the motor voltage is less than ~20% below the pack voltage, but after that it becomes very difficult to extract energy from the motor's phase windings.

My fear the other day was that if the fan did not turn on that I would not be able charge the IMA while the car was hot and I would go into the next day with a cold car and insufficient soc to maintain the DC/DC converter during warm up.
Overdischarging the pack (probably) won't happen (I haven't actually tested it though). Once the SoC drops below 10%, LiBCM flags out assist, at which point the MCM should disable the DCDC converter (to prevent further IMA battery drain). Obviously still not ideal, but shouldn't overdischarge the pack. By all means please test this out and report back if the SoC continues to drop below 10% (to prevent battery damage, stop testing if SoC drops below 8%).

Oh, I noticed today that the metal IMA Bay tray is ribbed. It looks like there is a room underneath the tray between the ribs where you could push in long thin resistive heaters for the FoMoCo batteries.
If you went this route, you almost certainly would need to power them from the 12 volt system... very unlikely you could safely feed HVDC in that small gap... which requires 3 mm creepage and clearance to any conductive surface.

It might be possible to use a gas tank heater and let the tank warm the battery. I'm not sure how energy efficient this would be, how easy it is to install gas tank heaters, or if we can insulate the gas tank. However google says that many types of tank heaters do exist.
A better option might be to place a heater between the fuel tank and the chassis (i.e. stick it to the chassis). I haven't explored FoMoCo heating options yet to know if that will be required... but hopefully not, because it's not an easy install for most people. Rest assured that I will come up with a FoMoCo solution... but not right this moment... obviously I'm open to any and all ideas.
 

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I'm open to any and all ideas
I found this a few days ago, it looked pretty interesting.
It could basically work the same as your resistor matrix PCB design. I don't really have the knowledge to accurately compare the two, but it could possibly be made cheaper/faster/thinner.
 

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As long as the fans are on, no amount of insulation is going to increase the efficiency... we'd need the fans to be off before blankets/foam added any appreciable insulation... it's like having a jacket unzipped while biking down a hill.
I'll be the 1st to say .. Disclaimers .. the thoughts I am about to share .. are NOT worth the significant added cost .. time , money , space , etc .. and still only likely to be worth doing with an external energy source.

.. but ..
Just for fun / to share .. a few ideas I've been tinkering with , along a similar topic point ..
3 parts

Part-1> Insulation
I've been tinkering with Panasonic's Vacuum insulated panels (VIPs) on different projects for a few years now .. allot of heat insulating R-Value for small thickness .. around R45 from only 15mm thick .. Maybe not the cheapest source .. but I've been going the 'easier to get route' , and just getting them from DigiKey as a Panasonic distributor , who has 13 sizes .. https://www.digikey.com/en/products/filter/miscellaneous/579?s=N4IgTCBcDaIG4EMDGBXFBbEBdAvkA

For comparison .. If/when size/thickness is not an issue .. It would take about ~10 Inches (~254mm) of conventional foam board thickness to thermally insulate as well as just 15mm thick of these Panasonic VIPs.

Using them is not all good .. to preserve the vacuum , you can't cut them , drill them , etc .. soo not as easy as other types of insulation that can easily be cut to fit whatever size.

Although these are about as good one can get for heat insulation per mm of thickness .. even this little mm of thickness is too many for the 'drop in' style design .. using such would I suspect require a completely custom cold weather install .. in order to move things and change things enough to gain those mm.

If we have an box roughly IMA Battery size surface area .. about 330mm x 160mm x 390mm .. If we managed an overall package thermal performance of R30 .. In a 20C dT ambient around it .. aka 68F inside when 32F outside .. that super insulated box will loose heat at a rate of only about ~1.2watts .. or about ~1.8 watts at 30C dT (aka about 14F outside 68F inside).

Part-2> Air Flow heat loss
Heat recovery ventilators look at that issue for houses .. they transfer some ~80% or so of the heat in the exiting / exhaust air into the incoming / intact fresh air .. this can work both ways .. retain cold air conditioning temperature in summer , and retain warm heating temperature in winter.

One of the smallest size devices that can function like this are the flat plate heat exchangers .. designed for thicker fluids like water , but will thermally work for air as well .. although again custom work .. there should be space in the air intake path from behind the seat to the battery box for the heat exchange to take place.

A valve could be opened and closed when one wants to retain some of that 'waste' heat in the exhuast air .. or flipped when one wants to just exhaust it.

Part-3> Over 1 COP
How many wh of heat do you get per wh of electricity spent .. 1 for 1 is COP 1 .. ie you get 1 for every 1 you spend.
The easy to use , robust , inexpensive , etc .. resistance heaters are nearly ~100% efficient converting the wh of electricity spent into wh of heat .. only tiny bits of magnetic and other .. thus it does make allot of sense why they are often used.

Although compressor style heat pumps are much better able to get around 2-3 COP for heating they are massive larger , noisier , etc .. sometimes getting 2 or 3 wh of heat for every 1 wh of electricity spent is worth it.

For any heat pump of any size to work .. it would need a source to pull heat from .. soo I only see this as possible as a add-on to further improve the Part2 above for the waste heat in the exhaust air.

A middle ground between those two are the solid state Peltier modules .. not as big or as efficient as the compressor heat pump .. but they can still allow one to get over 1 COP for heating , you get the resistance nearly ~100% and you also get any wh of heat energy they pull from the cold side as well .. thus for heating they do better than cooling .. Peltier COP varies considerably with conditions .. I've seen allot of people just run them at max dT which is not as good for COP .. I've attached an example heating COP graph , for cooling reduce the COP on the y axis by at least 1 for all points on the graph .. highest heating COP is not at 100% max module power , instead it is usually around low load 10% to 20% of module max .. and the higher the dT the lower COP , eventually by 30C dT they are worse than COP1.

Soo (for example ) ..
Part#1 could vastly reduce the heat loss while valve closed up / parked , over night , over weekend , etc.
Part#2 could save / reuse around ~80% of the heat wh in the exhaust air.
Part#3 could then give more heating watts than one spends in electrical watts taking heat from and thus cooling the exhaust air down.


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Discussion Starter · #78 ·
i bring my 90 lb. dog everywhere with me. i couldnt stomach leaving him at home by his lonesome where he hates it. he always beats me to the car to go with, with passenger seat removed and the whole passenger floor lined with thick comforters and thick poly-fill large dog beds that i rotate through the laundry. he eats like a horse, those calories really help keep the cab warmer. his thick coat is built for my climate, right before the lake ice'd over i took him there so he could go swimming. he didnt want to leave the water.
yesterday i was helping a friend insulate inside his new 30x40 workshop on his property. it was 4F outside and windy, his dog and my dog are good friends, they ran around and played outside all day in that crap. i had to install a two-gang outlet on the outside of the building.. reluctantly i had to warm my hands up inside by the temporary propane heater twice just so i could get it done. 4f and windy means frostbite on exposed skin in short order. we were able to get the entire 12' high ceiling covered with 6 mil poly and it got warm enough in there that i could remove my jacket. i still had a 5 layers of shirts underneath but hey, a noticeable improvement. our next steps will be nailing 3/4" thick pine boards to the entire ceiling so we can pump about 24" of blow-in insulation up there. it is just a workshop and the goal is to get it insulated enough so the concrete floor doesnt freeze with minimal btu's spent. insulation is expensive but fuel prices are climbing. dogfood has gone up quite a bit too.
 

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I briefly looked into designing the PCB without discrete resistors... the primary issue I ran into with trace heating is that the power source for the LiBCM heater is much higher voltage (up to 250 volts) than most extant PCB trace heaters (e.g. 12 volts). When I did the math, I needed 3200 feet of trace to safely emit that much heat... and that's if I used a 1 ounce copper, impedance controlled PCB with 0.004" trace width (which is prone to failure over time due to narrowness).

Even spread out over QTY3 PCBs, I would have still needed to route 1000' of trace on each PCB. Even if that was possible (it wasn't), the resulting heater would have zero redundancy... any trace breakage anywhere would cause the entire heater to fail.

So yes the PCB trace heater concept is excellent, but in this case it didn't work.

...
@IamIan:
I haven't seen the commercialized vacuum panels you mentioned before. Neat! As you mentioned, they look pretty fragile... not sure they would hold up in the hands of most G1 Insight owners ;). Since you've used them, how much abrasion resistance do they have? If a bolt head rubbed on them for 20000 miles, do you think they'd still be vacuum sealed?

These vacuum panels are likely overkill unless the entire battery is wrapped. Even a couple small holes for airflow (when desired) would compromise the overall insulation value of the pack. Honestly I think 'standard' non-flammable insulation (e.g. rockwool) is probably sufficient (in conjunction with a heating element). No need for exotic materials... even an R-1 insulation rating would be a vast improvement versus the exposed aluminum surfaces inside the IMA bay.

Aside: I believe aerogels have a higher R-value (and are also more fault tolerant), but they are also even more expensive than the vacuum panels you mentioned.

One issue with heat recovery ventilation is condensation, which has to be evacuated similar to a drip line on a heat pump. Energy recovery ventilators solve this problem, but are also considerably more expensive.

...

As always, I enjoy reading all these creative ideas. Keep them coming! As with most engineering efforts, the 'correct' solution is always a compromise between cost, complexity, and availability.
 

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Why not power the resistive heating elements from the 12V DC-DC converter? Less efficient, sure, but at least you have use of the car at really low temps. I recently bought some conductive tape (for EMI use, more like a fabric) and found it was resistive enough to potentially be used as a source of gentle heat. Not sure how it would hold up or if it would develop hot spots if the current path narrowed due to wear and breakage (and then burn down your car).
 
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