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Tesla App reducing charging current by itself?
- Thread starter NJcarowner
- Start date
What is the model number of your HPWC ? Any messages or red lights?
I would be really surprised if its the app that's doing it. Try turning off your phone overnight to see if it happens again.
How do I check the model number? I have restarted the phone multiple times. It will charge at 48 amps but tomorrow will be back at 18
Yes, that's the model number, and that's probably not overheating, Time to try the 'turn off the phone' experiment, I guess. Probably going to have to get Tesla involved.
AlexHung
Member
My car drops the charge current from 10A to 9A recently. I got a message in the car in the morning alerting me. It says it’s reduced due to fluctuating voltage, or something along that line.
andaconda
Active Member
Same here -- start the app at 48 amps only to find it sometime later at 47 amps. Not a real big issue, but it would be if it were any lower.
The 47 vs 48 issue I believe is related to the app. Change amps in the car instead of the app to see if that sticks.
Going to 18 automatically is not the app. There must be overheating somewhere or the voltage drop is too big and the car reduces its draw. Check your message log.
Going to 18 automatically is not the app. There must be overheating somewhere or the voltage drop is too big and the car reduces its draw. Check your message log.
MikeHolliday
Member
Do you know what size wire was used from your Breaker Box (Load Center) to the Gen3 Wall Connector and the distance between the two. If you are running a wire gauge that is too small you will get a voltage drop and the car will reduce the current to prevent wire overheating and causing a possible fire... A loose connection at the Breaker or at the Wall Connector could cause the same issue...
I noticed a similar issue on my MY the other day. Played with the new app and reduced my amperage to 23 (from 24) just to check it out. Set it back to 24 but no matter what I did with the app, it would not hold 24, it kept going back to 23 when I checked in. Finally went to the car and set it back to 24 and it is holding that now. Something's amiss and it's probably the app.
Android - 4.3.0-766. MY - 2021.36.5.1
Android - 4.3.0-766. MY - 2021.36.5.1
MikeHolliday
Member
Check the size of the conductors (wire) that was used between your Breaker and the Wall Connector, they should be a minimum of 6 gauge, but ideally 4 gauge. Next make sure that the Connectors at the Wall Connector and the Breaker are properly tight.
MikeHolliday
Member
I am willing to bet that it is not the App. I have a Model Y and am running the Android App Version 4.3.0-766 and the Car is running Version 2021.36.8.8. My Voltage sometimes runs as high a 248 volts and it will be charging at 12Kw instead of 11Kw which it is rated and I am absolutely seeing no drop is charge rate.
I'd tend to agree that its a bad connection or incorrect wiring or potentially even a bad circuit breaker.
Don't forget you can go to 'Driving...Service...Notifications' in the in-car screens to see notifications that may have been displayed but timed-out during the overnight charging sessions.
Don't forget you can go to 'Driving...Service...Notifications' in the in-car screens to see notifications that may have been displayed but timed-out during the overnight charging sessions.
MikeHolliday
Member
I can tell you for a fact that I have seen many botched installations where the Conductors were undersized. Remember that most of the time a Continuous Load requires a wire one gauge larger than would normally be used. Since a 6 gauge wire is rated for only 55 Amps and a 48 Amp draw times 125% (See code below) gives you 60 Amps which means that a 4 gauge wire is required for a 48 Amp draw.
NEC 210.20(A) Specifies that overcurrent protection devices "shall be sized to not less than the noncontinuous load plus 125 percent of the continuous load."
NEC 210.19(A)(1) "...minimum branch-circuit conductor size...shall have an allowable ampacity not less than the noncontinuous load plus 125 percent of the continuous load."
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I had the same problem on my Model 3 with iOS: played with the amperage in the app for fun and, from there on, it kept setting it back to 6A.
And the solution that worked was the same: went to the car and set it back to 32A in there.
SilverString
Member
It's not the app. Line voltage above 240v can cause the 47-48 amp variance as the car tries to regulate the total draw to near 11.5 kilowatts. Mine is often 248v at 47 amps, which results in an 11.7 kW charge. The car display will show the voltage, current, and total kilowatts when charging, so it's pretty easy to verify. I am pretty sure the app is just mirroring the car data.
andaconda
Active Member
The 3's charger can actually deal with around 285 input volts, at least. There's no effort to regulate the total draw to 11.5kw, unless maybe it was added via software in the past year. The Gen2 HPWC was happy with 277V as an input and I've regularly seen 285V at 48 amps, leading to around 13.7kw. It was great, and I still don't know why they stopped supporting it in the Gen3. Technically, they didn't officially support it in later Gen2's either, but it was just a manual change.
Additionally, it'll deal with input voltages around 185V, although not when it starts at a 'normal' ~240V. This was actually on the same charging post as the 277V, but via a different J1772 charger that had to be connected to a 208V supply, and by the time it hit the car it was more like 190V or so.
ATPMSD
Active Member
This most commonly occurs when the seasons change and the connections in the Wall Charger expand and contract. Trip the breaker, open the Wall Charge and torque the wire attachment screws. I would also do this, cautiously, in the breaker box. It could be other issues as noted above, but this is an easy one to do.
Good luck!
Good luck!
