Erratic Touchscreen Behavior when Using 16V Outlet

[P-Rock]

I'm trying to figure out a way to run my work laptop inside my 2022 M3 LR for more than the 90 minutes it lasts when using the battery by itself. To that end, I purchased a Jackery 300, which I can plug into the 16V outlet, and I can plug the laptop into that. The laptop uses an enormous 240W power brick, but I've noticed during average workloads I'm probably only pulling 60-100W (as reported by the Jackery), with peaks near 200W when the GPU is going full tilt. The Jackery itself can support loads of up to 300W continuous. When the Jackery is plugged into the 16V outlet, it will recharge its battery at anywhere from 70-100W, depending on the SOC of the Jackery battery. The seems to be well under the 12A continuous at the 16V the manual claims this outlet is capable of. That means in theory I should be able to run my work laptop essentially indefinitely as long as I'm not doing constant heavy workloads.

The problem I'm having is that when the car is parked and the Jackery is plugged in, sometimes I get really erratic touchscreen behavior--it either won't respond to touch inputs at all, or it will respond schizophrenically. Unplugging the Jackery almost always makes the behavior go away immediately (although I did have to reboot once to return the touchscreen to normal) The behavior doesn't happen 100% of the time when plugged in, but it happens enough to be annoying. It doesn't appear to happen at all when the car is actually driving, but the fact that it's acting up while parked is making me nervous I'm going to somehow kill my 16V battery or some other component hooked up to it. Switching to different modes to keep the 16V turned on--camp mode, keep climate control on, etc. doesn't fix the issue when parked. The warning in the Tesla manual to not plug any non-Tesla approved accessories into the 16V outlet, especially if they're interfering with the electronics is not making me feel any better (does Tesla even make any accessories that use the 16V outlet?) I should note that I've had zero issues with the touchscreen while the Jackery is not plugged in.

Any idea what's going on here? Should I be worried that using the Jackery will somehow permanently damage my 16V battery or touchscreen?

 

[Unclepaul]

Some accessories are rated for 16 volts. Others are not.

 

[stopcrazypp]

Here's a few things you can troubleshoot:

Touchscreen:
See if there is anything on the touchscreen (especially wet) or if there is a screen protector (note if your car was bought used, some screen protectors may be almost invisible). You can try putting it in screen cleaning mode and cleaning, but make sure to dry off screen or it may freak out (may require a reboot).

Jackery overloading or electrical interference:
What happens when it is plugged in and charging but there is no load? Then what about when it is full and no load? And then what about when there is a load on the Jackery for both cases?

Jackery not rated for 16V?:
Issue may also be the input on the Jackery is not rated for 16V (check the specs) so it is causing interference. When car is parked, there may be less load on the 16V bus, so the voltage may rise vs when driving . If you have a voltage meter on the cigarette outlet you may be able to see this.

Electromagnetic interference through the air instead of through the connection:
What happens if the Jackery is out further away from the screen? What about if outside the car or in the trunk (if possible to test)? A metal sheet or box may also shield it. If the interference is through the connection, sometimes a magnetic choke on it may help (the ones you see on some power cables).

 

[P-Rock]

Here's a few things you can troubleshoot:

Touchscreen:
See if there is anything on the touchscreen (especially wet) or if there is a screen protector (note if your car was bought used, some screen protectors may be almost invisible). You can try putting it in screen cleaning mode and cleaning, but make sure to dry off screen or it may freak out (may require a reboot).

Jackery overloading or electrical interference:
What happens when it is plugged in and charging but there is no load? Then what about when it is full and no load? And then what about when there is a load on the Jackery for both cases?

Jackery not rated for 16V?:
Issue may also be the input on the Jackery is not rated for 16V (check the specs) so it is causing interference. When car is parked, there may be less load on the 16V bus, so the voltage may rise vs when driving . If you have a voltage meter on the cigarette outlet you may be able to see this.

Electromagnetic interference through the air instead of through the connection:
What happens if the Jackery is out further away from the screen? What about if outside the car or in the trunk (if possible to test)? A metal sheet or box may also shield it. If the interference is through the connection, sometimes a magnetic choke on it may help (the ones you see on some power cables).

Jackery specs say it takes 13.6V +-1V for input. I'm not sure what the 16V outlet is actually outputting when I'm parked vs. driving, although I can get a multimeter and check later.

If the issue is that the Jackery can't take the input 1) why does the Jackery unit itself seem to behave fine and 2) how would the Jackery not being able to take 16V screw with the screen or other things connected to the 16V battery?

 

[stopcrazypp]

Jackery specs say it takes 13.6V +-1V for input. I'm not sure what the 16V outlet is actually outputting when I'm parked vs. driving, although I can get a multimeter and check later.

If the issue is that the Jackery can't take the input 1) why does the Jackery unit itself seem to behave fine and 2) how would the Jackery not being able to take 16V screw with the screen or other things connected to the 16V battery?

It may seem to behave fine but it may cause dirty power or different RFI levels or signals (whatever FCC requirements it met during testing may no longer apply given the voltage doesn't match test conditions).

 

[bobkart]

If the issue is ~16V being marginally too high for the Jackery, a DC-to-DC converter like this could clear that up:

https://www.amazon.com/MGGi-Converter-Regulator-Waterproof-Transformer/dp/B09T9XJ4ZX

Input can range from 8V to 40V, and output is 13.8V at up to 10A. Such a converter could also provide isolation of suspected electrical noise coming from the Jackery's DC input, preventing it from reaching the 16V bus. There is some conversion loss of course.

 

[jankratochvil]

You probably won't like the answer but happily running my Lenovo 65W from a 100W cigarette lighter USB-C adapter. My wife's HP laptop worked only a bit (turning off the charging) despite officially it should work from USB-C 100W source (despite with lower performance). So I also bought a powerbank with 140W USB-C output and that works fine for my wife's HP laptop's 100W demand. One could apparently chain it for charging from the cigarette lighter adapter.
The issue is if your laptop understands a mode with reduced performance from USB-C. Besides that I had disabled GPU on my laptop (nouveau.blacklist=1 rd.driver.blacklist=nouveau) as (I have) no use for any GPU myself and the Intel integrated gfx card works much better anyway regarding its driver. This is not tested with my Tesla (Volkswagen Caddy) but I hope it would be the same.

 

[P-Rock]

You probably won't like the answer but happily running my Lenovo 65W from a 100W cigarette lighter USB-C adapter. My wife's HP laptop worked only a bit (turning off the charging) despite officially it should work from USB-C 100W source (despite with lower performance). So I also bought a powerbank with 140W USB-C output and that works fine for my wife's HP laptop's 100W demand. One could apparently chain it for charging from the cigarette lighter adapter.
The issue is if your laptop understands a mode with reduced performance from USB-C. Besides that I had disabled GPU on my laptop (nouveau.blacklist=1 rd.driver.blacklist=nouveau) as (I have) no use for any GPU myself and the Intel integrated gfx card works much better anyway regarding its driver. This is not tested with my Tesla (Volkswagen Caddy) but I hope it would be the same.

So the first thing I tried was an 120W inverter that can work with 16V. Was hoping I could at least trickle charge the laptop when it was off (since I measured it was only charging at about 50W while off but charging). But merely plugging in the power brick caused the inverter to shut off. I could also buy a ~100W power adapter that *might* trickle charge it, but at that point I'm spending almost as much as I would be to just get something like a Jackery, and wouldn't even keep the laptop charged while I was using it.

 

[P-Rock]

Jackery not rated for 16V?:
Issue may also be the input on the Jackery is not rated for 16V (check the specs) so it is causing interference. When car is parked, there may be less load on the 16V bus, so the voltage may rise vs when driving . If you have a voltage meter on the cigarette outlet you may be able to see this.

I measured the voltage coming out of the 16V outlet while parked, and it was about 15.5V. I had someone measure the voltage while I was driving, and it was exactly the same voltage. Still too high for the Jackery according to the spec sheet, but it doesn't appear that there's any voltage sag on the 16V bus while driving.

 

[jankratochvil]

What is the "power brick"? Do you use AC adapter of the laptop converting DC 16V->AC 110V->DC xV? That gets hot, sometimes it trips Tesla cigarette lighte fuse (for ~15 minutes) and it just feels too heavyweight to me.
My suggestion was to use direct DC 16V->DC 20V adapter. 20V can vary based on negotiated DC voltage according to USB Power Delivery for the USB-C connector. Some laptops can accept USB-C charging despite their original AC adapter is plugged in by some custom connector.

 

[stopcrazypp]

I measured the voltage coming out of the 16V outlet while parked, and it was about 15.5V. I had someone measure the voltage while I was driving, and it was exactly the same voltage. Still too high for the Jackery according to the spec sheet, but it doesn't appear that there's any voltage sag on the 16V bus while driving.

So the difference between parked and drive isn't voltage, not sure what it would be then. Have you tried testing the physical distance/separation between screen and Jackery to see if it may be interference through air instead of the connection?

 

[P-Rock]

I'm trying to figure out a way to run my work laptop inside my 2022 M3 LR for more than the 90 minutes it lasts when using the battery by itself. To that end, I purchased a Jackery 300, which I can plug into the 16V outlet, and I can plug the laptop into that. The laptop uses an enormous 240W power brick, but I've noticed during average workloads I'm probably only pulling 60-100W (as reported by the Jackery), with peaks near 200W when the GPU is going full tilt. The Jackery itself can support loads of up to 300W continuous. When the Jackery is plugged into the 16V outlet, it will recharge its battery at anywhere from 70-100W, depending on the SOC of the Jackery battery. The seems to be well under the 12A continuous at the 16V the manual claims this outlet is capable of. That means in theory I should be able to run my work laptop essentially indefinitely as long as I'm not doing constant heavy workloads.

The problem I'm having is that when the car is parked and the Jackery is plugged in, sometimes I get really erratic touchscreen behavior--it either won't respond to touch inputs at all, or it will respond schizophrenically. Unplugging the Jackery almost always makes the behavior go away immediately (although I did have to reboot once to return the touchscreen to normal) The behavior doesn't happen 100% of the time when plugged in, but it happens enough to be annoying. It doesn't appear to happen at all when the car is actually driving, but the fact that it's acting up while parked is making me nervous I'm going to somehow kill my 16V battery or some other component hooked up to it. Switching to different modes to keep the 16V turned on--camp mode, keep climate control on, etc. doesn't fix the issue when parked. The warning in the Tesla manual to not plug any non-Tesla approved accessories into the 16V outlet, especially if they're interfering with the electronics is not making me feel any better (does Tesla even make any accessories that use the 16V outlet?) I should note that I've had zero issues with the touchscreen while the Jackery is not plugged in.

Any idea what's going on here? Should I be worried that using the Jackery will somehow permanently damage my 16V battery or touchscreen?

UPDATE: So I bought an EcoFlow River 2, which is similar to the Jackery but rated for 12-24V DC input. As far as I can tell, this battery does not cause any erratic behavior with the touchscreen when plugged into the DC outlet. I plan to use this battery for a road trip in a couple of days and will report back if I notice anything, but I think the problem is solved.

 

[P-Rock]

UPDATE: So I bought an EcoFlow River 2, which is similar to the Jackery but rated for 12-24V DC input. As far as I can tell, this battery does not cause any erratic behavior with the touchscreen when plugged into the DC outlet. I plan to use this battery for a road trip in a couple of days and will report back if I notice anything, but I think the problem is solved.

UPDATE 2: I used the ecoflow on a 3 hour road trip and it worked great. No weird car behavior and the 16V outlet was more or less able to keep the Ecoflow topped off with charge even though my work laptop can pull 200+ watts intermittently. I would recommend replacing the stock fan if you go this route though--it's obnoxiously noisy. I replaced per this procedure: EcoFlow RIVER 2 Noisy Fan Fix!