Model Y onboard charger Voltage Tolerance?

[Chickenlips]

I have been having issues all week with my car stopping it's charge. My voltage has been as low as 185v looking at a screenshot I took just before it cut out. Could this be the cause of my issues too?

 

[tomstephens89]

As @Astrape says don’t yet count your chickens….

You need to be measuring V at the charge point whilst the car charger is actually pulling a load to get a true gauge of the voltage drop / quality of (a) the supply (b) your cabling etc from the CU to your charge point.

Well, if when loaded with a car the charger pulls the voltage down due to resistance in the cabling from my CU to it, that's easily rectified with a bigger gauge.

What I am saying is my incoming supply seems to be fairing well with a 10kW load on it, smack bang on a Saturday afternoon.

Should probably say, we're quite well versed in electrical concepts etc due to work.

 

[Adopado]

I have been having issues all week with my car stopping it's charge. My voltage has been as low as 185v looking at a screenshot I took just before it cut out. Could this be the cause of my issues too? View attachment 919049

Wow ... I was going to chip in that I charged at 207V in the past (not at my address) and the car surprisingly didn't baulk ... but you win the prize on the low voltage parameter! Needless to say that really shouldn't be happening.

 

[Sean.]

What I am saying is my incoming supply seems to be fairing well with a 10kW load on it, smack bang on a Saturday afternoon.

Cool but 10 kW is not much of a load. You should be able to pull the full rated draw of the DNO fuse and still be within supply voltage tolerance

 

[tomstephens89]

Cool but 10 kW is not much of a load. You should be able to pull the full rated draw of the DNO fuse and still be within supply voltage tolerance

No but its more than what the car would pull and typically I wouldn't have barely anything else running whilst the car is charging overnight.

When I ran the 10kW up, my voltage was reading 235 so still well within tolerance. I can fire up some more load as a test but I don't yet have a car to charge!

 

[Astrape]

I have been having issues all week with my car stopping it's charge. My voltage has been as low as 185v looking at a screenshot I took just before it cut out. Could this be the cause of my issues too? View attachment 919049

Crikey! It could be causing a problem with the charger. Do the car notifications say the car stopped the charge? If not it may well be the charger has a low voltage limit. My Zappi for example according to the interweb trips on undervoltage at about 200V. Does the charger provide any information? What is the supply voltage before charging starts? Does it vary a lot coming into the property?

 

[Casss]

Does anyone know the voltage range of the MY onboard charger for the UK market?

As Tesla don't publish this information, you're really into the territory of needing to speak to someone at Tesla, or reaching out to someone like Performance EV or Ingineerix who have done a teardown on the Gen2/Gen3 onboard chargers.

https://www.youtube.com/@PerformanceEV

Question is, is this a problem for the onboard charger? I have a feeling the low points may well be (~208v) but what about the high (~264v)?

Probably? Possibly? Again unless someone from the engineering team from Tesla is on here, you're unlikely to get a solid answer. I'd imagine it would do something to remediate and continue charging if at all possible, but reaching a point where the wild inconsistency is making it unhappy you'd probably want it to shut things down right?

Just out of curiosity, has your friend tried forcing the charge at lower amps in the car?

 

[Chickenlips]

Crikey! It could be causing a problem with the charger. Do the car notifications say the car stopped the charge? If not it may well be the charger has a low voltage limit. My Zappi for example according to the interweb trips on undervoltage at about 200V. Does the charger provide any information? What is the supply voltage before charging starts? Does it vary a lot coming into the property?

My supplier was supposed to be coming today to measure everything, as they think it is an issue their end, but as is usual with these things... They didn't turn up.