I have been having regular charging issues lately with voltage dropping......I have checked all connections and it still drops while home charging......is there anything I am missing or is there something I can do to fix it......is it software or car issues....thanks for helping.....BTW: it started doing the same thing on my wifes Model 3
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charging voltage dropping from 40a to 30a
- Thread starter r1200gs4ok
- Start date
Your title suggests that you are having charging rate (amperage) dropping. If you have voltage dropping then you could have a wiring issue. Have an electrician check it for you. If your car detects voltage drop it will decrease the charging rate to protect you.
BTW: it started doing the same thing on my wifes Model 3
It's not your car then. Either the charger or its plug/wiring should be looked at before you have a problem because Teslas do this when they detect too much resistance (which means heat somewhere).
It's not your car then. Either the charger or its plug/wiring should be looked at before you have a problem because Teslas do this when they detect too much resistance (which means heat somewhere).
thanks...I checked the cable from the charger to the car and it is not hot.....I can hardly feel any warmth......the Nema plug is slightly warm.....I did notice that the green running light showing the charger is working had a middle light that was red ........all was free running down the charger but there was one red light that showed every other time it scrolled down.....
I guess what I am trying to say is that when the charger is supplying power through the cable to the car, the running green lights from top to bottom sometimes has a red light in the middle...all green light from top to bottom and a single red light in the middle......what does that mean
Ciaopec
Active Member
Cannot get the PDF to load properly; you may have to rotate the view. Otherwise:
https://www.tesla.com/sites/default...hscreen_Mobile_Connector_Owners_Manual-au.pdf
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SilverString
Member
It's a charger fault of some kind. As in the above attachment I would turn off the breaker, reset the HPWC, and turn the breaker back on to see if that helps.
will try that....thanks
found the reset.....I made a mistake when I said "red light"......it is the middle light which is "orange".......when running, it goes from "green to green" (top to bottom) and sometimes the middle light glows "orange".....
all plugs and cables are barely warm.......wonder it it is the charger or car
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murphyS90D
Member
Were copper ferrules installed on the ends of all of the wires at the wall charger and in the main panel? If not and any of the strands of wire did not get clamped that becomes a heat spot that will increase the resistance. If the car detects increasing resistance it automatically reduces the current.
ucmndd
Well-Known Member
If the car detects a large voltage drop while charging, it backs off to 75% of the max rate.
What does the car report as the input voltage at the start of charging, and what does it report when it reaches full speed after a minute or two?
What does the car report as the input voltage at the start of charging, and what does it report when it reaches full speed after a minute or two?
when it starts charging, it shows 40amps......it ramps up to 40 in about 15-30 seconds.......it stay at 40amps for around 30 min.......then it drops to 30 amps for about 6-15 min.......then the cycle starts again.......when it finishes the charging at the desired setting (90%) the report shows whatever is pumping into the car at the time it stopped charging......average amps are anywhere 32.5 and 40......
what is funny is when I look at the charger......it was streaming green lights at 40amps from top to bottom until the amperage drop......then at the 30 amp drop it shows a yellow/orange light in the middle of the green lights......this cycle continues.....when I start charging the other car, it has the same issues...cycling between 30amps and 40 amps
I started charging at 2108......ramped to 40amps......monitoring with iPhone and teslafi......stated it should take 1hr 5 min......will report back at 2108 with status
edit 1: well I did the reset of the charger before I started this charge......set car at 48max amps and it started charging.......charger stayed at 40amps for 45 minutes....then with 10 minutes let, the amps dropped to 30amp...
I have a mobile service set up for Monday to look at this issue...all connections are tight
edit 2: I unplugged the car and unplugged the wall charger from the Nema 14-50......the plugged the car back in and started charging at 40amps....
edit 1: well I did the reset of the charger before I started this charge......set car at 48max amps and it started charging.......charger stayed at 40amps for 45 minutes....then with 10 minutes let, the amps dropped to 30amp...
I have a mobile service set up for Monday to look at this issue...all connections are tight
edit 2: I unplugged the car and unplugged the wall charger from the Nema 14-50......the plugged the car back in and started charging at 40amps....
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murphyS90D
Member
You have a wall charger connected to a 14-50? A wall charger is supposed to be hard wired to the power panel.
Trebek1762
Let's play jeopardy
It’s the wiring of your wall charger. Your car is trying to prevent you from burning down your house.
Huachipato
Member
You should note what the voltage to the car is. My house, for example, will show anywhere between 240 - 247 Volts on the IC when plugged in. If we are busy cooking, running AC and what not - I've seen it drop down to 238Volts - that's just the house pulling more amps than normal and the natural change is a slight drop in voltage as a result. The car in these moments might drop down to 39 or 38 amps - that is all normal.
A high resistance drop will drop - which is what is suggested is the issue you have - would drop the voltage to something way lower than normal, like maybe 200 or 180 volts. That alone would indicate there is a problem with the wiring. It also as a result would drop the amps from 40 to something way lower (like 30 amps).
You mentioned you had TeslaFi. If you look at your charging history to see if there are any clues there. Go to "Charges" -> "Charge Summary" and then click at your home location to see a report like what I have below:
A high resistance drop will drop - which is what is suggested is the issue you have - would drop the voltage to something way lower than normal, like maybe 200 or 180 volts. That alone would indicate there is a problem with the wiring. It also as a result would drop the amps from 40 to something way lower (like 30 amps).
You mentioned you had TeslaFi. If you look at your charging history to see if there are any clues there. Go to "Charges" -> "Charge Summary" and then click at your home location to see a report like what I have below:
thank you....my issue is just that......starts at 40A and drops down to 30A...then cycles until complete....my voltages are constantly reading 232-233.....I believe someone suggested that my problem is a result of wiring to a Nema 14-50 and I should wired directly to the charger.....I will check this and make necessary adjustments in the waiting......Looking at your attachment for Teslafi indicated a steady 240V and 40A...thanks for the feedback...Will advise what I see and what my corrective action will be
I believe you may be correct......mine is wired to Nema 14-50.......Never had it hard wired and never got constant 240V or 40A......Will take corrective action by wiring directly to the panel on 50A breaker and see if that solves my problem....thank you very much for the assistance.
Your problem is likely a loose connection. It could be at the breaker, the connection to your 14-50 outlet, or the outlet itself could be worn out. (The cheap Leviton ones from Home Depot, etc., are known to be of poor quality and can fail.)
The other possibility is that the wire used is too small for the load.
Hi Mike.....the wiring used is 6awg.......I spoke to the electrician who did the job and he is coming by this afternoon to troubleshoot and take measurements......trouble is, Tesla does not offer this charger anymore so it will be interesting to see if after we determine it is not an electric issue how they will handle it.....I have 2 cars, a M3 and MS......dont like to supercharge now so charging my car from 20% to 90% takes ~8 hours at the reduced 30A......I am hoping it is just a loose connection or bad outlet....will let you know later this afternoon or tonight after he comes.....
are there any other options you can suggest if there is no more HPWC available? Maybe a Mobile Charger with Nema 14-50, as along as it gives me 40A.......thanks
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