Well I happen to not be familiar with any of those things
Excellent write up, thank you!Like the OP, I live in a rural area and depend upon my Cybertruck as "Plan A" to provide emergency backup power for my home. That's a critical issue for me because without power I don't have running water - I am on a well. And without running water my pipes will freeze (98-year-old farmhouse).
Unlike the OP, I don't have PowerShare. I utilize the 9.6 kW available at the outlets in the bed.
Just to clarify, warming the CT's battery pack is quite easy and only consumes a few percent of available pack charge. Just turn Climate on from the app. That's it. Do NOT turn on Window Defrost or Windshield Wiper Defrost or Heated Seat or Heated Steering Wheel or anything else. Just Climate.
If the pack temp is cold enough, pack heating will begin (in addition to cabin heat).
Here's an example of that pack heating process, from just a few hours ago, with a CT NOT plugged in:
Of note, had the vehicle been plugged in and had access to house power the pack heating would have continued for another ~15 degrees. The BMS set point is different for plugged-in versus not plugged-in. Tesla has also tweaked those set points across different software releases. This was on 2025.45.8.
Also of note, if your vehicle is plugged in it will very likely begin charging at some point (because you've dropped far enough below the set charge level due to the losses from cold and from Climate being on). Turn charging off when that happens. Use all available power to heat the pack, then worry about charging.
And, yeah, it's unfortunate that Tesla does not provide access to pack temps through the normal UI or app. Having access to that information is the singular reason I use 3rd-party apps.
Hopefully for the OP, simply raising pack temps using the Climate control will resolve his problem.
However.... there may be more to the story. There was for me.
I did not lose power during the recent storm. But like millions of others I prepped for that possibility. In my case, that meant bumping the charge level of my CT to 80% - rather higher than I normally keep it - and then unplugging and backing the truck up next to my house (not plugged in, as my L2 TWC is located at one of my sheds, 175' away). With the truck parked, I ran a 50' generator cord from the 240v outlet in the bed to the single-circuit transfer switch at my well head; and a 10 AWG extension cord from one of the 120v outlets into my home for ancillary power. The tonneau cover remained closed; but the tailgate had to be open because of the cords. To prevent snow ingress I draped a canvas tarp over the rear of the vehicle.
This setup worked great during two winter storms last year, where we did lose power.
Alas.
Eighteen hours into this year's storm, which began as 6-8" of snow before turning to sleet and freezing rain - but with utility power still going strong - I decided to run some THD (total harmonic distortion) comparisons from the comfort of my living room. I also had my "Plan B" backup (a Honda EU7000is inverter gas generator) set up and it was one of the few times I had ready access to all three power sources.
Plan B:
Utility power measured very clean, as expected: 123v, 60.01 Hz, 2.1% THD.
Turning to the Cybertruck (which I knew would likewise be clean, as I had measured it a year ago), I turned on the bed outlets via the app. A couple seconds later the extension cord I had run to the truck went hot.... but, then, in a surprise, just as quickly went back off.
The CT was throwing an HV_BATT_a294 error and telling me to reset the outlets directly on the truck's screen.
The long and the short after numerous attempts.... resetting the error on the truck's screen would initially clear the fault. However, every attempt to then re-energize the bed outlets (even with both cords unplugged) would result in the fault reappearing.
My "Plan A" was dead in the water.
Service Mode didn't provide any other insight, other than that it also contained a bunch of PCS2_a103_IsoTempSensorIrrational codes. I had to laugh at those. The CT apparently thought about as much of this weather as I did.
The rest of this is speculation, so feel free to take it or leave it.
I do NOT think the truck is broken. I have not booked a service ticket.
What I think happened was that the sustained cold temps (ambient had been 16-18F for many hours) combined with the high humidity from the storm - it wasn't foggy but the air was otherwise dense with moisture - and that perhaps exacerbated by my leaving the tailgate open overnight.... led to a ground-fault or isolation-fault within the (not hermetically sealed) inverter subsystem.
Tesla's leakage current thresholds are very conservative - that's a good thing. But the downside of such safety-conscious design is a narrowing of the environmental envelope in which that design can work.
The next day - yesterday - the storm had passed. It remained very cold, but the sun came out and humidity noticeably decreased. I warmed the CT's pack (using Climate, as described above), moved the truck back to its normal parking spot next to the shed, bumped the charge back up, and let it rest in the sun all afternoon.
This morning, with the truck once again backed up to the house, I energized the bed outlets and they stayed on. Still very cold (ambient of 7F), but much drier.
Numbers were excellent: 119.8v, 60.01 Hz, 2.2% THD.
My conclusion at this point is that the Cybertruck remains an excellent alternative for powering one's home if grid power goes down. But there are likely environmental conditions which can cause it to fail earlier than some other solutions (like a good ICE generator).
In the future I'll leave the tonneau and tailgate closed. Opening them only in the event that we lose grid power. Hopefully that will help.
Along with having a "Plan B."
