The car reports a 16amp limit on the main display but then tries to draw more current than the limit.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
L2 charging,,, Car pulls more amps than the set amp limit
- Thread starter DuncanM
- Start date
The car reports a 16amp limit on the main display but then tries to draw more current than the limit.
So it's showing 17/16A? If that's the case, it sounds like it could be an issue with the OBC.
zoomer0056
Active Member
Oh man, second time seeing something like this. When I voice command "set temperature to 70" the temp is set to 71 F. When I say "set temp to 72" it gets set to 73F. So I decided to try something. "Set temp to seventy point zero" .... guess what, the temp is set to 70F. The only thing I can come up with is some intern programmer and their software reviewers allowed a round up error. REDICULOUS. That has to be what you're seeing too. An intern programmer programmed in a round up error!
Yes, if I set the car's amp limit via the Charging Menu or Tesla App at 15amps, it will display 16/16A, and if I set it at 16amp it will briefly display 17/16A and then the EVSE faults and stops the charge.
Yes, that's my worry. But I want to confirm it with the Tesla Mobile Connector and a Tesla NEMA 6-20 adapter.
OxBrew
Active Member
Take pictures of the 17/16A, then stop doing that and open a service ticket. I'd stop use if that charger entirely, just to be safe. But the car should never allow that.
That's messed up, and needs to be fixed. It might not just be you, there could be a bad error in the code they need to correct asap.
That's messed up, and needs to be fixed. It might not just be you, there could be a bad error in the code they need to correct asap.
I'll have to wait until I drive the car and drop the SOC before I can test it and take a photo of the display.
What happens if you plug into a public EVSE? Does it say something like 33/32A? Also, what software version are you running on the car? That's pretty bad if the hardware isn't enforcing the current limit outside of software.
Last edited:
I can try that as there's an L2 charger about 10 miles away.
The car firmware is 2023.2.12
RayK
Active Member
Did you perform a manual re-boot (2 button hold) after the update? If not, try that and see if it makes a difference.
SageBrush
REJECT Fascism
You misunderstand how this all works.
The car can request 1,000 Amps for all that it matters. The Amp draw is the lowest of the car demand and the EVSE maximum. If the EVSE max is 16 Amps, the car will get 16 Amps.
Go back to your EVSE and look up the error code. We'll go from there.
It would be best if you could take some pictures of the 17/16A display in the car as others have suggested. Is the 17/16A display consistent or jumps between 17/16A and 16/16A? In any case, it's not unusual for EV's to pull a bit more or less than the limit (<1A) and the display could be off due to rounding errors. This also applies to the charging power display in Tesla.
I did that and it seemed to help.
However, I did a reboot via the Service Menu Tire configuration and now the car seems to be back to 'normal'. The amp limit set in the car is also the same as the amps being reported via the EVSE display. I am a bit concerned about the voltage drop at 16amps, so as a precaution I set the car amp limit to 15.
The car amp limit is now consistently being followed and the car now reports:
15/16A 232v (Edit: now fluctuating between 233 and 234V)
As I change the car amp limit up or down the change is reflected within a few seconds on the main summary display (as above) and in the EVSE's LCD display.
Last edited:
Yesterday the car would consistently report 1amp over the set limit: If I set a 14A limit it would show 15/16A for minutes at a time (for as long as I kept it under observation).
Today the reboot, as previously mentioned above, seems to have fixed the issue.
Only if the car software is behaving.
The EVSE has no ability to control current other than tripping the contactors.
The car does not request current, it draws as much as it wants, but it should be limiting itself to less than the EVSE's advertised capacity.
In this case, the car's software had a glitch and was allowing a charge rate higher that the EVSE's broadcasted max.
Edit: if Supercharging, the car does specify max current (and maybe voltage) and the L3 system provides up to that.
It's always good to reboot after firmware updates. It often needs to recalibrate/reset things.
Your EVSE has a safety mechanism that cuts power if the car tries to draw too much, so I'd set the car back to unlimited so that you can see if there's still an issue. If there is still an issue, you want to know, and you should complain. This is definitely something that should lead to a recall if it's happening in multiple vehicles because it's a major safety issue.
Pretty disturbing that the OBC hardware isn't limiting the current draw to the advertised value. It shouldn't be possible to override this in software.
Agreed, software would not be doing what software is supposed to if this is the case. Especially strange since the UI is showing the correct EVSE and incorrect charger values. It may be the vehicle has an internal check that it would fault on, but EVSE the is tripping first.
I'll experiment with it when I get the SOC down at some point. Anyways, if this is a common issue then I'd expect others to report similar problems.
Similar threads
- Question
