Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Charging amps on Mobil connector dropping to 8

RobB723

New Member
Mar 29, 2022
3
0
NY
I have had the car for a week now. First 5 days charging from the Mobil connector at home in my garage I was getting 12 amps. Then past couple days been mostly getting 8 amps. I did notice on the Mobil charger how Tesla letters flash green normally but the T would sometimes be red. When I was getting 8amps I would push the adapter into the charger part with some force and it would go to 12 amps. The outlet is not hot and not using an extension cord.

Is this normal? How do I disconnect the adapter from the Mobil unit to try to unplug
And re plug in?anyone else have a similar problem? Do I just have an adapter and Mobil unit with bad connections? I don’t drive that much per day and at home every night for charging so I honestly don’t need more then the 12 amps. But 8 amps is a little low and also worried I’m being charged 12 amp electric rate to only put 8 amps into the car.
 

RayK

Safety Score 92 (Getting better after 400mi drive)
Apr 5, 2016
2,716
2,785
San Jose, CA
First off, it's a "mobile" connector. Mobil is the company we are all trying very hard to avoid.

You can remove the NEMA adapter, the part that's plugged into the mobile connector and then goes into the outlet in the wall. It does take some force to pull it out it straight out. Look at the connection at both ends (the NEMA adapter and the input to the mobile connector). If things look clean, you can then plug it back in. Generally the process is called "re-seating". Since you said that your charging session returns back to 12A, that area might be your problem. You should also inspect the NEMA plug pins and make sure that they are not dirty. Look at the other end of the mobile connector; the plug that is inserted into your car's charge port and inside the charge port itself. You can also try to reset the breaker that controls the outlet by flipping it off and then back on.

Other than that, I can think of nothing else you can do with your current mobile connector. If you know somebody else with a Tesla, you can try borrowing their mobile connector (and NEMA adapter if they have one that fits your outlet) and see if it acts the same. If it does, then the problem is most likely with your outlet or your car.

You're not going to be charged a higher cost for a "12A electric rate" if the mobile connector falls back to 8A. The amount of power consumed by the car should be the same. There is a small amount of power being diverted from the main battery pack to power other items in your car but overall, the electricity cost should even out, despite taking longer to charge the car at 8A than with 12A.

For reference, this is what a NEMA adapter looks like when disconnected from the mobile connector:

 
Last edited:
  • Helpful
Reactions: Rocky_H
Upvote 0

RobB723

New Member
Mar 29, 2022
3
0
NY
First off, it's a "mobile" connector. Mobil is the company we are all trying very hard to avoid.

You can remove the NEMA adapter, the part that's plugged into the mobile connector and then goes into the outlet in the wall. It does take some force to pull it out it straight out. Look at the connection at both ends (the NEMA adapter and the input to the mobile connector). If things look clean, you can then plug it back in. Generally the process is called "re-seating". Since you said that your charging session returns back to 12A, that area might be your problem. You should also inspect the NEMA plug pins and make sure that they are not dirty. Look at the other end of the mobile connector; the plug that is inserted into your car's charge port and inside the charge port itself. You can also try to reset the breaker that controls the outlet by flipping it off and then back on.

Other than that, I can think of nothing else you can do with your current mobile connector. If you know somebody else with a Tesla, you can try borrowing their mobile connector (and NEMA adapter if they have one that fits your outlet) and see if it acts the same. If it does, then the problem is most likely with your outlet or your car.

You're not going to be charged a higher cost for a "12A electric rate" if the mobile connector falls back to 8A. The amount of power consumed by the car should be the same. There is a small amount of power being diverted from the main battery pack to power other items in your car but overall, the electricity cost should even out, despite taking longer to charge the car at 8A than with 12A.

For reference, this is what a NEMA adapter looks like when disconnected from the mobile connector:

Thanks for the reply. I will try to pull out. Didn’t want to put too much force as I was worried about damaging
 
Upvote 0

Rocky_H

Well-Known Member
Feb 19, 2015
7,981
10,116
Boise, ID
How many volts is the app/car showing when you first plug in compared to about a minute later? If you're receiving too much voltage drop (due to the circuit being shared, poor wiring or other problems), the car will reduce charging power by 25%, although that would put it at 9 amps, not 8.
I was thinking of this one too when I first saw this thread yesterday. The car measures the voltage before charging, and then once it ramps up to the full amps of charging, checks voltage there, and if there is a really big voltage drop difference, it thinks that could be a problem with a connection in the circuit, so it will back off to 3/4 of what the charging amps were, but that would be 9/12. However, we have also seen a couple of threads of a display problem where people's OCD is going nuts because they are seeing 31/32 or 47/48 on the mobile app display because of a software bug. Maybe it's these two things together? It's lowering to 9, but displaying as 8?
 
  • Like
Reactions: Big Earl
Upvote 0
...

You're not going to be charged a higher cost for a "12A electric rate" if the mobile connector falls back to 8A. The amount of power consumed by the car should be the same. There is a small amount of power being diverted from the main battery pack to power other items in your car but overall, the electricity cost should even out, despite taking longer to charge the car at 8A than with 12A.

For reference, this is what a NEMA adapter looks like when disconnected from the mobile connector:


That "small" amount of power is actually a big deal at these low amperages. At 120v, 12 amps, the car draws 1440watts of which somewhere around 400w goes to overhead, leaving you about 1040w actually getting to the battery. Cut that down to 8 amps, and you draw 960w, subtracting 400w, leaves only 560w going to the battery, almost doubling your charging time and increasing the overall power used by quite a bit.
 
  • Informative
  • Like
Reactions: Thp3 and Rocky_H
Upvote 0
I also use the mobile charger in my garage with a dryer outlet type connector. Been working great for 1.5 years. Last week had a flashing red T on the charger and was getting half the amps. Unplugged for 24 hours and it has been fine since...need to do some troubleshooting to see if it is the actual charger or the outlet, but can't reproduce the issue now.
 
Upvote 0

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top