New X100D charging at reduced amps

[bob_p]

We picked up our X 100D last week and have been charging it using the same Tesla 14-50 connector (on a 50A circuit) that we were using with our 2012 S P85.

We've noticed the X 100D will start at 40A and then reduce the amps to 26 or 27 by the end of charging.

Has anyone else seen this?

Has Tesla changed the charging algorithm to introduce tapering for home charging?

Is there an incompatibility between the 14-50 connector and the new cars?

Or could we have a problem with the onboard charging hardware?

 

[Need]

Are you charging it to 100%? After SOC reaches 85% to 90%, it will start reducing the current. I think by the time you get to 100%, it will be at under 20A. But if you see it goes down way before 80%, there may be something wrong. I know when we first got our MX, the charge port was really tight. We can't push it all the way in and the charge port will be orange (instead of green). It charges at a reduced rate.. I think around 20'ish.

 

[Tozz]

Please define what you call 'end of charging'. At which SoC does it taper off?

As @Need has said already it is normal that the amps lower as you reach higher SoC. When supercharging this happens pretty fast, at somewhere around 60% SoC it will slow down. Obviously the same will happen when you charge at home, but since the charge current is lower it happens later in the charging process.

 

[GOPJEW]

We picked up our X 100D last week and have been charging it using the same Tesla 14-50 connector (on a 50A circuit) that we were using with our 2012 S P85.

We've noticed the X 100D will start at 40A and then reduce the amps to 26 or 27 by the end of charging.

Has anyone else seen this?

Has Tesla changed the charging algorithm to introduce tapering for home charging?

Is there an incompatibility between the 14-50 connector and the new cars?

Or could we have a problem with the onboard charging hardware?

Do you have Teslafi?

Yes - sort of - I have reported this to Tesla for my XP100D - I have a Gen 1 mobile charger I have kept on the wall for 3 years to charge my S - When I use my X it will have a "Charging Interrupted" notice and then drop from 40 to 30 (unfortunately, the vehicle then sets to 30 amp to charge).

My first X had no problems, my 3 month loaner X had no problems, but my new one does have issues. A buddy brought his S over and charged at 40 no problem, I paid an electrician to come over and check the 14-50 - he said all was good (wasted $150) with the plug. When I reset to 40 amp in the vehicle it will charge at 40 for a few days, and then have a problem and go back down to 30.

I am guessing this is what the software update on the Mobile Connector was referring to.

 

[ewoodrick]

We picked up our X 100D last week and have been charging it using the same Tesla 14-50 connector (on a 50A circuit) that we were using with our 2012 S P85.

We've noticed the X 100D will start at 40A and then reduce the amps to 26 or 27 by the end of charging.

Has anyone else seen this?

Has Tesla changed the charging algorithm to introduce tapering for home charging?

Is there an incompatibility between the 14-50 connector and the new cars?

Or could we have a problem with the onboard charging hardware?

Some reduction is normal for batteries. As the battery's voltage increases, the charging current decreases. That's why, if you are on a trip, it is best to Supercharge near an empty battery than a full one. Even a Supercharger rate drops as you charge. It is also why the last part of the charging takes longer.

 

[P85_DA]

As @GOPJEW mentioned teslafi is real helpful ..I have been reading various threads on charging issues and doesn’t seem to be any pattern etc ...I have gen 1 hpwc at 100a and normally set to 64a or 48a ...this thread had me check teslafi as seen below ..I don’t have this issue with 2018 XP100 MCU1 and HPWC gen 1

 

[bob_p]

Charging only to 90%. Since we've only had a few days to observe this, I'll start doing more detailed analysis - and verify there is a pattern of tapering at the charge approaches 85-90%.

 

[GOPJEW]

Charging only to 90%. Since we've only had a few days to observe this, I'll start doing more detailed analysis - and verify there is a pattern of tapering at the charge approaches 85-90%.

TeslaFi will help you with a charging log and efficiency per charge - then you will know for sure.

 

[bob_p]

A simpler test will be to swap our 2017 S 100D and 2018 X 100D in our garage. The S 100D charges on our 100A HPWC (even though it only has the 48A onboard charger activated) and appears to get constant 48A when charging to 90%.

If I swap them, and the S 100D starts tapering on the 14-50 and the X 100D gets a constant 72A when charging to 90%, then the issue isn't car-specific.

The next test will be replacing the 14-50 connector and trying our Gen 1 and Gen 2 UMC's using the 14-50 adapter - and see if there's any difference in charging. If not, then it's likely software tapering. If the behavior is different with one or both of the UMC's, then it could be an issue with our 14-50 connector.

TeslaFi is also an option, though it's pretty easy to see in the car or on the smartphone app if the charging is running at reduced amps.

 

[bob_p]

Moved our X 100D over to our 2013 HPWC (one of the first delivered, used with our 2012 S P85). The HPWC is on a 100A circuit, able to charge up to 72A on the X 100D - and shortly after connecting our new X to the HPWC, the HPWC trips its internal breaker, the charging ring goes to red, and a "check charger" message is displayed on the dashboard.

I moved our 2017 S 100D over to the 14-50 connector, and it charged up to 90%, staying at a constant 40A.

Since the HPWC & 14-50 connector have been working reliably with our 2017 S 100D and with our 2012 S P85 (which was the trade-in for the new X), the problem appears to lie with the X 100D.

I called Tesla's phone support, and they recommended scheduling a Service Visit (late next week) to look at the charger.

Then, I got a call back from Tesla's charging team, and got a different explanation. Evidently they are seeing these issues with other vehicles delivered recently, likely with the new MCU2 (with the faster Intel processor). It appears the MCU2 vehicles are having handshake problems with the Gen 1 HPWC and Gen 1 connectors (probably includes both the UMC and the 14-50 connector). I suspect there is a timing issue in the handshake software - and with the faster processor, the handshakes aren't reliable - and are the cause of these problems. It's possible Tesla focused testing on the MCU2 with the Gen 2 HPWC and UMC, which is why we're having problems - with relatively old hardware purchased for previous Tesla vehicles.

If you are seeing these issues, contact Tesla's phone support group and see if they can put you in touch with the charging team, so they can tag your vehicle and add it to the list.

If these issues are caused by MCU2, then it's likely this can be fixed with a software update, though it may take them 1 to 2 months to find the problematic code, make a fix, test it, and then put it into the pipeline for distribution.

At least for home charging, our 14-50 connector does charge the car, even if it does it slower with charging dropping down to around 26A.

The larger concern is destination charging - ending up at a hotel or destination that has an Gen 1 HPWC, and finding out that it can't be used at all. Until Tesla gets this corrected, we'll make sure that when we take a road trip, we have an alternate charging option - either a supercharger, public J1772 charger (which is probably not affected), or using a 30A or 40A outlet with our Gen 2 UMC.

 

[GOPJEW]

Moved our X 100D over to our 2013 HPWC (one of the first delivered, used with our 2012 S P85). The HPWC is on a 100A circuit, able to charge up to 72A on the X 100D - and shortly after connecting our new X to the HPWC, the HPWC trips its internal breaker, the charging ring goes to red, and a "check charger" message is displayed on the dashboard.

I moved our 2017 S 100D over to the 14-50 connector, and it charged up to 90%, staying at a constant 40A.

Since the HPWC & 14-50 connector have been working reliably with our 2017 S 100D and with our 2012 S P85 (which was the trade-in for the new X), the problem appears to lie with the X 100D.

I called Tesla's phone support, and they recommended scheduling a Service Visit (late next week) to look at the charger.

Then, I got a call back from Tesla's charging team, and got a different explanation. Evidently they are seeing these issues with other vehicles delivered recently, likely with the new MCU2 (with the faster Intel processor). It appears the MCU2 vehicles are having handshake problems with the Gen 1 HPWC and Gen 1 connectors (probably includes both the UMC and the 14-50 connector). I suspect there is a timing issue in the handshake software - and with the faster processor, the handshakes aren't reliable - and are the cause of these problems. It's possible Tesla focused testing on the MCU2 with the Gen 2 HPWC and UMC, which is why we're having problems - with relatively old hardware purchased for previous Tesla vehicles.

If you are seeing these issues, contact Tesla's phone support group and see if they can put you in touch with the charging team, so they can tag your vehicle and add it to the list.

If these issues are caused by MCU2, then it's likely this can be fixed with a software update, though it may take them 1 to 2 months to find the problematic code, make a fix, test it, and then put it into the pipeline for distribution.

At least for home charging, our 14-50 connector does charge the car, even if it does it slower with charging dropping down to around 26A.

The larger concern is destination charging - ending up at a hotel or destination that has an Gen 1 HPWC, and finding out that it can't be used at all. Until Tesla gets this corrected, we'll make sure that when we take a road trip, we have an alternate charging option - either a supercharger, public J1772 charger (which is probably not affected), or using a 30A or 40A outlet with our Gen 2 UMC.

This is EXACTLY my problem. Thanks for this email and the update - I will do a formal report to get it in the queue.

 

[X Fan]

This is EXACTLY my problem. Thanks for this email and the update - I will do a formal report to get it in the queue.

Same...just picked my 2nd X today and now going red frequently. I called support but tech clearly was not knowledgeable about the problem. I'll call charging team on Monday.

As an aside, this 103K X was perfect with no punch list items.....

 

[DCGOO]

Then, I got a call back from Tesla's charging team, and got a different explanation. Evidently they are seeing these issues with other vehicles delivered recently, likely with the new MCU2 (with the faster Intel processor). It appears the MCU2 vehicles are having handshake problems with the Gen 1 HPWC and Gen 1 connectors (probably includes both the UMC and the 14-50 connector). I suspect there is a timing issue in the handshake software - and with the faster processor, the handshakes aren't reliable - and are the cause of these problems. It's possible Tesla focused testing on the MCU2 with the Gen 2 HPWC and UMC, which is why we're having problems - with relatively old hardware purchased for previous Tesla vehicles.

The larger concern is destination charging - ending up at a hotel or destination that has an Gen 1 HPWC, and finding out that it can't be used at all. Until Tesla gets this corrected, we'll make sure that when we take a road trip, we have an alternate charging option - either a supercharger, public J1772 charger (which is probably not affected), or using a 30A or 40A outlet with our Gen 2 UMC.

Thank you for this. My older HPWC continues to charge my 2015 Model S just fine. But not the New (last week) X. I had to break out the old UMC to charge the car. I have intermittently gotten it to work, but more often just the red ring. I hadn't considered the destination charger issue. I have a service appt set up for tomorrow, so your information was timely!

 

[X Fan]

I'd add I was able to finally get to my 90% charge setting....after several starts and stops, with a reset each time, I then sat in the X and turned on the AC; charge would begin and I left and overnight it became fully charged to 90% (I started at 10%).

However, it still turns red when I try to charge after a drive or later when cable is attached and car is calling for more energy to get charge back to my 90% setting.

btw: when charging is working, I can charge at any setting up to 72a max.

 

[bob_p]

If you only have a Gen 1 HPWC for charging an MCU 2 car, I suggest going into the HPWC and try manually reducing the maximum amps down to 30A, and see if that can help.

We were able to get a pretty good charge using a Gen 1 HPWC destination charger, which I suspect was set for 30-40A - charging for extended periods before stopping. Our home Gen 1 HPWC is on a 100A circuit and can charge up to 80A (72A with our new X) - and at that level, we get the red ring of death almost immediately after connecting to the HPWC.

if you have access to a 14-50, 10-30 or 14-30 outlet, use the Gen 2 UMC that comes with the car (you'll need to order a 10-30 or 14-30 adapter, since those don't come with the car). We've been using our Gen 2 UMC this weekend, and it's working reliably - providing us a steady 32A of charging.

If you call Tesla's phone support about this issue, tell them you are seeing the same charger problems that other recent Tesla buyers are also seeing - and you'd like to talk with someone in the charging group to verify there isn't a problem with your car.

I'm confident Tesla will fix this - this type of problem isn't unusual when real-time software starts running on a faster processor. Operations that ran fine on the slower processor now run too fast in real-time, which should be correctable with relatively simple fixes.

And because this is impacting the ability to charge at Gen 1 destination chargers, Tesla will likely try to get this fix out as soon as possible.

 

[X Fan]

Model S discussion on same problem: Series 1 HPWC issues with 2018 model S

 

[bob_p]

Until Tesla can distribute a software fix for this problem, Tesla should:

• Notify all MCU2 owners of this issue, even those that are only using Gen 2 charging hardware at home
• To help with road trips, they should provide a way for owners to determine which destination chargers are Gen 2, and should work with the MCU2 cars. Without that information, it's possible an MCU2 car may not be able to charge at some destinations on road trips.

​

For home charging, this issue likely affects only repeat Tesla customers who purchased Gen 1 hardware for previously purchased Tesla vehicles. But this likely will impact all recently built Tesla vehicles with MCU2 with Gen 1 destination chargers.

Hopefully Tesla can get this fixed quickly...

[posted this in both the S & X forums, in case some owners are only checking one forum. All MCU2 owners should be aware of this issue before planning to use a Destination Charger on a road trip.]​

 

[DCGOO]

My local Service Center gave me a new WC to replace my existing version 1 HPWC. I installed it and it works fine, so I am now good at home. But they had no response when I asked about what to do when encountering the older ones in the wild. It also explains why all the connectors (old version) near the Mall store, are now powered off.

 

[bob_p]

Our Gen 1 HPWC was replaced with a Gen 2 HPWC yesterday - and now our new X can charge at a full 72A at home.

Though...

After taking a short drive and putting the X back onto our Gen 2 UMC connected to a 14-50 outlet (charging at 32A), we received a "charger overheating" warning, and the charging was limited to 16A.

Took the car out for another short drive, and when we returned, the Gen 2 UMC worked successfully at 32A.

It appears someone else may have reported a similar issue when moving between a Gen 2 HPWC and the Gen 2 UMC.

Seems like Tesla needs to do more testing and software updates for MCU2 charging...

 

[X Fan]

Bob_p:

Thx for the update. Just got my X back from the detailer.

After about 7 attempts/resets, I was able to get my new X to charge.

I’ll probably take the same pathway as you and have a Gen2 HPWC installed.