I just had a really bad experience while leaving my Telsa at home while on vacation, and I wanted to post about it here, both in hopes that it will get the attention of some Tesla Firmware engineers and to warn others about the problem so that they won't experience the same problem.
My Tesla Model X (2017) has always had issues with charging at home. It trips the groundfault breaker. The original breaker tripped instantly when I started charging, as soon as it started drawing power. The replacement GFCI outlet just trips randomly after half a day or so.
Anyway, when I left the car, thanks to a chaotic schedule during the last few days, I failed to charge the car. That was a big mistake. So I left it at home with... I think about 60-ish miles of range. About a few days (and 2200 miles of flying) later, my phone notified me that the battery was dangerously low, and that I needed to plug my car in, or it might not be able to start. Yay.
So I called my next-door neighbor, and I unlocked the trunk remotely so that he could get the charging cord out and plug it in. It got up to 80-ish miles before it tripped the breaker. And then it ran back down, and I called him and he reset it for me again. And then it got too low again, and I asked him to reset it, but had to leave a message on his answering machine that time, and didn't dare even check the car to see if it was plugged in, assuming that I'd have a better chance of the car being functional if I didn't wake it up.
That was also a mistake. The car did not automatically start charging again. When I got home, the car was below zero miles of charge. It remarkably did wake up, showing a red charge light, and unplugging and replugging the cable got it charging, so I'm guessing that either being tethered keeps the 12V battery alive even if the car isn't actively charging or I got really lucky and just happened to get there right before I would have had to manually pop the frunk and connect a 12V charger to my 12V battery. I'm not sure which. I'm guessing the latter.
During this fiasco, I called Tesla and asked them to send a field service person out. They did some pre-diagnostic work from the service center, and said that the car was waking every three hours. They had me change my password just in case something was talking to their API and waking the car. I did. No change in power consumption. They also suggested turning cabin overheat protection off, but there was no way to do that from the other side of the country.
In the end, Tesla said there was nothing that a mobile tech could do to diagnose it in the field. Had they sent a tech, the tech probably would have immediately noticed the giant power inverter plugged into the 12V power jack with its light lit.
But wait, you say. The 12V power jack is turned off except when the car is turned on, right?
Wrong.
The 12V jack is turned off except when the computer wakes up. And when cabin overheat protection is turned on, it can wake up a lot. So I had the double whammy of it being a hot couple of weeks and a power inverter with an 85W power supply (disconnected from any device, but still using power) connected to the accessory port. The result was that my car was burning through about 15 miles per day of range while sitting turned "off". So that three-week trip cost me $40 in electricity as a result, and the car's failure to restart charging nearly left me manually charging the battery.
Of course, when it gets below 20 miles, cabin overheat protection turns off, so it burned through its usual four miles per day down near the bottom, but that was just barely enough for it to survive from when I checked it Monday to when I got home late Friday night.
Tesla, PLEASE fix this. Specifically, please:
These sorts of problems just shouldn't happen. They just shouldn't.
My Tesla Model X (2017) has always had issues with charging at home. It trips the groundfault breaker. The original breaker tripped instantly when I started charging, as soon as it started drawing power. The replacement GFCI outlet just trips randomly after half a day or so.
Anyway, when I left the car, thanks to a chaotic schedule during the last few days, I failed to charge the car. That was a big mistake. So I left it at home with... I think about 60-ish miles of range. About a few days (and 2200 miles of flying) later, my phone notified me that the battery was dangerously low, and that I needed to plug my car in, or it might not be able to start. Yay.
So I called my next-door neighbor, and I unlocked the trunk remotely so that he could get the charging cord out and plug it in. It got up to 80-ish miles before it tripped the breaker. And then it ran back down, and I called him and he reset it for me again. And then it got too low again, and I asked him to reset it, but had to leave a message on his answering machine that time, and didn't dare even check the car to see if it was plugged in, assuming that I'd have a better chance of the car being functional if I didn't wake it up.
That was also a mistake. The car did not automatically start charging again. When I got home, the car was below zero miles of charge. It remarkably did wake up, showing a red charge light, and unplugging and replugging the cable got it charging, so I'm guessing that either being tethered keeps the 12V battery alive even if the car isn't actively charging or I got really lucky and just happened to get there right before I would have had to manually pop the frunk and connect a 12V charger to my 12V battery. I'm not sure which. I'm guessing the latter.
During this fiasco, I called Tesla and asked them to send a field service person out. They did some pre-diagnostic work from the service center, and said that the car was waking every three hours. They had me change my password just in case something was talking to their API and waking the car. I did. No change in power consumption. They also suggested turning cabin overheat protection off, but there was no way to do that from the other side of the country.
In the end, Tesla said there was nothing that a mobile tech could do to diagnose it in the field. Had they sent a tech, the tech probably would have immediately noticed the giant power inverter plugged into the 12V power jack with its light lit.
But wait, you say. The 12V power jack is turned off except when the car is turned on, right?
Wrong.
The 12V jack is turned off except when the computer wakes up. And when cabin overheat protection is turned on, it can wake up a lot. So I had the double whammy of it being a hot couple of weeks and a power inverter with an 85W power supply (disconnected from any device, but still using power) connected to the accessory port. The result was that my car was burning through about 15 miles per day of range while sitting turned "off". So that three-week trip cost me $40 in electricity as a result, and the car's failure to restart charging nearly left me manually charging the battery.
Of course, when it gets below 20 miles, cabin overheat protection turns off, so it burned through its usual four miles per day down near the bottom, but that was just barely enough for it to survive from when I checked it Monday to when I got home late Friday night.
Tesla, PLEASE fix this. Specifically, please:
- Make sure that every power management feature that is available from the console is also available from the mobile app. The worst time to realize you have a problem with power consumption is when you're away from home, and if there's no way to fix the problem, that's a huge flaw, made worse by the realization that it could be fixed with ten seconds in Interface Builder plus adding maybe twenty lines of code in total, spread between the app and the car.
- Add code to detect unusual rates of power consumption while sleeping and warn the user. That power inverter had been plugged in and turned on for a while, but I didn't notice it because I was only making one trip out per week and charging all the way up each week. But the car knew that it was drawing way more power than usual, and could easily have warned me in time to switch that off before I left on vacation.
- Automatically try to restart charging for any charging failure, regardless of cause, as soon as power is reapplied. Every. Time.
- If possible, draw enough power off of the UMC to keep the 12V systems running even if you aren't actively charging the main battery.
- Fix the UMC v2 design so that it doesn't leak enough current to constantly trip 110V GFCI outlets.
These sorts of problems just shouldn't happen. They just shouldn't.