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EMF while Supercharging

Destiny1701

22’ M3 LR - ‘The Dark Night’
Nov 28, 2015
1,718
1,361
Canada
Moderator note (bmah): The first thirteen-ish messages in this thread were split off from a discussion of personal safety.

I would first say never sit in the car while it’s charging...especially at high 600v supercharging.
The amount of EMF in the car jumps tremendously. Similar to your cell phone emissions while charging vs not.

Not sure how to address safety other than charge at home.
 
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BerTX

Active Member
Supporting Member
May 2, 2014
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Texas/Washington
I would first say never sit in the car while it’s charging...especially at high 600v supercharging.
The amount of EMF in the car jumps tremendously. Similar to your cell phone emissions while charging vs not.

Not sure how to address safety other than charge at home.
Yet you own a Tesla? Just wondering at what point between the 400V constant of the battery while you apparently are safe driving and the 600V (I don't know if that's right, didn't look it up) while Supercharging do you think it becomes hazardous.
 
Any solutions beyond knives and bear spray and 911? (please skip the gun debate here)

I would love to see Tesla come up with an "Emergency Charger Eject" feature.
good luck.

Yet you own a Tesla? Just wondering at what point between the 400V constant of the battery while you apparently are safe driving and the 600V (I don't know if that's right, didn't look it up) while Supercharging do you think it becomes hazardous.
From what I've heard (from someone who takes all this very seriously, owns an EMF reader and a Tesla), the car does not emit anything harmful while driving, however there is enough to be concerned during supercharging. He has advised that I not sit in the car while supercharging.
 
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Destiny1701

22’ M3 LR - ‘The Dark Night’
Nov 28, 2015
1,718
1,361
Canada
Yet you own a Tesla? Just wondering at what point between the 400V constant of the battery while you apparently are safe driving and the 600V (I don't know if that's right, didn't look it up) while Supercharging do you think it becomes hazardous.

Charging and discharging are 2 very different scenarios. Yes I own a Tesla and the amount of EMF during driving and at traffic lights is within acceptable limits. I’ll attach the link to a 2015 study conducted. However while charging, the EMF increases dramatically beyond what the researchers considered safe and acceptable.

And no I’ve never sat in it while it’s charging.
 

BerTX

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May 2, 2014
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good luck.


From what I've heard (from someone who takes all this very seriously, owns an EMF reader and a Tesla), the car does not emit anything harmful while driving, however there is enough to be concerned during supercharging. He has advised that I not sit in the car while supercharging.
Dang, something new to Google...
 
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BerTX

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May 2, 2014
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Texas/Washington
Charging and discharging are 2 very different scenarios. Yes I own a Tesla and the amount of EMF during driving and at traffic lights is within acceptable limits. I’ll attach the link to a 2015 study conducted. However while charging, the EMF increases dramatically beyond what the researchers considered safe and acceptable.

And no I’ve never sat in it while it’s charging.
Thanks, I'd appreciate that link. I don't Supercharge except when travelling (I guess by definition since the nearest SC is 90 miles) and usually get out of the car, but not intentionally to avoid the pox. I just get numbutt.
 

wdolson

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Jul 24, 2015
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good luck.


From what I've heard (from someone who takes all this very seriously, owns an EMF reader and a Tesla), the car does not emit anything harmful while driving, however there is enough to be concerned during supercharging. He has advised that I not sit in the car while supercharging.

I have an EMF meter, but I haven't supercharged in a while. The car is a fairly good Faraday Cage. The i3 with it's carbon fiber body isn't which is why the Model S has AM radio and the i3 has it disabled.

A cheap EMF test is to turn on an AM radio. EMF really messes up AM reception. You can also find the source of EM noise by walking around with an AM radio.

Yeah ... I like the comfort of the car. No doubt. You are the one who has to determine the safety of where you are at and decide to stay in your car, watch your car from a distance away, or just not stop there. There are variables for every situation. We all have to determine what is the safest option for us.

But I can tell you, with complete certainty, that getting out that first time was by far the best decision I could have made. That security guard story? There was a lot more to it, but it involves stalking, a gallon of water removed from my gas tank the next day, notes, the guard (Tom) waiting for me after work (I ran a bar then), etc. And I was out on the desert, well away from my car, when I saw his van pull up and eventually saw him take his flashlight out looking around the area. That was the first time I got out & it was probably because as my car started to sputter and lose power, I finally figured out that he was behind all the times my car wouldn't start & he was right there to help. And more. (Gaaah, I haven't thought about that night and that guy for years. Super creepy.)

I always listen to my gut & am really glad I did so that night. And it's always an option.

I like your idea of getting out of the car and hiding in the dark a ways from the car. One thing that would make most potential perps run is to announce you have a gun out in the dark.

“The women of this country learned long ago, those without swords can still die upon them.”
― Eowyn, The Two Towers - Lord of the Rings

Skip the gun "debate" at your peril (what exactly is 911 going to be bringing anyway?)

Without the "great equalizer" all you have is:

1.) Alert mind (environmental awareness)
2.) Size relative to attacker
3.) Hand to hand combat training
4.) Other Weaponry (the more lethal the better)

I bought my daughter a Glock when she was born, no self imposed defensive disadvantages for her when she is of age.

I've been by myself Barstow at 2:00AM with businesses closed, wife/kids sleeping in the car and had have had someone bigger approach me at night.

He prefaced the encounter with "I'm not going to rob you or ask for money or anything". I said "I appreciate that, how can I help you?"

He wanted to know how supercharging worked. Happy to explain it all to him. He had no idea and I gave him no idea I was capable of defending my family if needed.

Was a good conversation (at 2:00am) and happy to share the joys of Tesla ownership to someone who didn't know much about them.

But like many safety supplies - "better to have it and not need it, than need it and not have it."

My SO taught a woman's self defense class for the Portland police many years back. She is the nicest person in the world until someone seriously crosses the line, and then they are dead. She found it amazing that many of the women in the classes just wouldn't do what it took to protect themselves if things went pear shaped.

She does DV perpetrator counseling and she's only had one client who I felt was a threat (from the way she talked about him, I never met him). She said all the other guys in group felt it too and would hang around until the creepy guy left. I felt she was only in danger if surprised, if she saw him coming, he was probably not getting out of there with both eyes, or possibly his life. I made sure she had pepper spray. Interestingly the week after she got the pepper spray he didn't show up for group and she found out the next day he was re-arrested for putting a woman in the hospital.

Most of the guys she counsels are people who just never learned how to deal with conflict appropriately and once they are given the right tools, they straighten out their lives. Her agency screens everyone coming in and reject anyone who shows signs of being a sociopath, but this was at another agency before she got hers going and they didn't screen very well. Among the guys she has accepted for treatment, the recidivism rate is tiny.
 

mongo

Well-Known Member
May 3, 2017
14,560
49,224
Michigan
Charging and discharging are 2 very different scenarios. Yes I own a Tesla and the amount of EMF during driving and at traffic lights is within acceptable limits. I’ll attach the link to a 2015 study conducted. However while charging, the EMF increases dramatically beyond what the researchers considered safe and acceptable.

And no I’ve never sat in it while it’s charging.

Please post that paper as it makes no sense to me.
Driving: up to (more for P/L) 1000 Amps being turned into a high frequency switched waveform to create a rotating sinusoidal field of up to 400V (full pack voltage) in an induction motor (S/X).

Charging via Supercharger: up to 400ish amps of DC current going into the battery. No switching, no AC. All this creates is a static magnetic field. Pack voltage is irrelevant for this case.

HV cables are closely routed so the opposing field cancel for the most part.
Worst case field calculation if the cables carry 500 amps and are 3 inches apart:
At 6 inches from closest wire: 2.19 gauss (a little over 4 times the Earth's field strength)
At 12 inches from closest wire: 1.09 gauss (double the Earth's field)
At 24 inches: 0.18 gauss (less than half ambient Earth field)
Values are much smaller if wires are properly routed (closer together).
For reference: a refrigerator magnet is about 100 gauss

During AC charging, there is localized switching in the charger itself, but that should be fairly contained.

Regarding the thread topic (but not very helpful), I once hit a deer which took out my radiator, got a lift to a payphone to call for help. While waiting for police/parents a van pulled up. Turned out the clerk in the gas station was afraid to come out to check the pumps because I was at this phone 250ish feet from the store by the road. Not every big dude in shorts at night standing around is a threat.
 
All this creates is a static magnetic field. Pack voltage is irrelevant for this case.
People wear magnets for pain relief. Has anyone noticed less aches and pains after a Supercharger session? Maybe that's one of the many reasons people love long distance travel in a Tesla, even though it takes longer. I know this seems off topic, but it might be relavant to personal safety.
 

BerTX

Active Member
Supporting Member
May 2, 2014
3,508
3,657
Texas/Washington
Please post that paper as it makes no sense to me.
Driving: up to (more for P/L) 1000 Amps being turned into a high frequency switched waveform to create a rotating sinusoidal field of up to 400V (full pack voltage) in an induction motor (S/X).

Charging via Supercharger: up to 400ish amps of DC current going into the battery. No switching, no AC. All this creates is a static magnetic field. Pack voltage is irrelevant for this case.

HV cables are closely routed so the opposing field cancel for the most part.
Worst case field calculation if the cables carry 500 amps and are 3 inches apart:
At 6 inches from closest wire: 2.19 gauss (a little over 4 times the Earth's field strength)
At 12 inches from closest wire: 1.09 gauss (double the Earth's field)
At 24 inches: 0.18 gauss (less than half ambient Earth field)
Values are much smaller if wires are properly routed (closer together).
For reference: a refrigerator magnet is about 100 gauss

During AC charging, there is localized switching in the charger itself, but that should be fairly contained.

Regarding the thread topic (but not very helpful), I once hit a deer which took out my radiator, got a lift to a payphone to call for help. While waiting for police/parents a van pulled up. Turned out the clerk in the gas station was afraid to come out to check the pumps because I was at this phone 250ish feet from the store by the road. Not every big dude in shorts at night standing around is a threat.
And aren't the Superchargers just stacks of the same charger that is in the car? I repeat -- IN THE CAR.
 

mongo

Well-Known Member
May 3, 2017
14,560
49,224
Michigan
Seems like if it were a problem, it would be much worse at the close range and unshielded by the car body when AC charging. Unless the chargers themselves are not producing the EMF?

The place you connect the car is just a cord holder. The racks of charger units are in the white cabinets behind the decorative screening. So if you sat at a picnic table near that enclosure, you would be closed to the source of emissions than if you were in your car.

Installed units are required to pass FCC conducted and radiated emission testing also.

The car's charger is inactive during supercharging.
 

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