Dual charger limited to 40 amps?

[sxnahm]

I had a second charger installed in my S 85D in October, and since then I've tried to charge at a few HPWCs that I believe were able to deliver more than 40 amps (one station was 72 amps, one was 80 amps), but in all cases the car only took 40 amps. When plugged into one of these HPWCs, the max rate is shown as expected, and the current setting on the charging panel matches that max rate. But the charge current never goes above 40 amps.

This could be an installation problem that I need to get fixed at the service center, but I wanted to see whether anyone else experienced this after having a second charger installed. Or maybe there is something I am not doing right?

 

[stevezzzz]

My Sig S came with dual chargers but I have only a 14-50 at home. More than a year after I took delivery I had my first opportunity to plug into an HPWC and was dismayed to find I was only charging at 40A (it was during a road trip and I was counting on 80A to keep to schedule). After a call to Ownership and some remote diagnosis, I was told that my slave charger was inoperative. Tesla replaced it at my next service visit.

 

[jgs]

I ordered my Sig S with dual chargers but had only a 14-50 at home. A year later I had my first opportunity to plug into an HPWC and was dismayed to find I was only charging at 40A (it was a road trip and I was counting on 80A to keep to schedule). After a call to Ownership and some remote diagnosis, I was told that my slave charger was inoperative. Tesla replaced it at my next service visit.

Thanks for posting this, I also ordered with dual chargers and also found I was only charging at 4 A with the HPWC at the hotel I stayed at a few weeks ago. I chalked it up to the HPWC being listed incorrectly, but I see I should go and double-check somewhere else.

 

[sxnahm]

I sent an email to my local service center, and got this response: "[FONT=&quot]t appears that we failed to change the vehicle’s software configuration so that it recognizes that the second charger is installed." [FONT=&quot][/FONT][/FONT]A bit later I then got this reply: "[FONT=&quot]I asked a field support engineer to change your car’s software configuration to match the hardware we installed. Please try charging on a HPWC again to confirm that you’re able to charge above 40A.[/FONT]"

It may be a while before I am back at a charger with over 40 amp capability, but hopefully I will now be able to get the higher rate.

Moral of the story: after getting a second charger installed, confirm that it is actually capable of charging over 40 amps before you take a trip an discover this on the road.

 

[siai47]

You would think that your local service center would have a HPWC at their location and would have used it to check their work before releasing the car back to you. I would suspect that almost all service centers now have one or more HPWC's available for their own "fleet" and/or for the service department.

 

[FlasherZ]

You would think that your local service center would have a HPWC at their location and would have used it to check their work before releasing the car back to you. I would suspect that almost all service centers now have one or more HPWC's available for their own "fleet" and/or for the service department.

For the longest time, the St. Louis service center didn't have the electrical capacity to install HPWC's at 100A and only had a number of 14-50's along the back wall and at the shop positions. It wasn't until they took over more of the building that they built out capacity for them. So some service centers may not be able to.

 

[stevezzzz]

You would think that your local service center would have a HPWC at their location and would have used it to check their work before releasing the car back to you. I would suspect that almost all service centers now have one or more HPWC's available for their own "fleet" and/or for the service department.

And you would think that my service center (which has several 80A HPWCs) would have checked that both my chargers were functional during the car's first annual service, which occurred a few months before I tried to use an 80A HPWC for the first time, myself.

 

[StaceyS]

Just a note on dual charger operation:

I've found that when you plug into a higher amperage charger, the primary charger activates first and ramps up the amperage to its rated (39 or 40 amps). It then sits there for a bit and then the secondary charger kicks in and the amperage ramps up again (79 or 80 amps, depending on the source). The time between the point at which the primary charger reaches capacity and the secondary charger activates has varied for me, sometimes its as little as 10-15 seconds, sometimes its as much as a minute or so.

 

[Cyclone]

Just a note on dual charger operation:

I've found that when you plug into a higher amperage charger, the primary charger activates first and ramps up the amperage to its rated (39 or 40 amps). It then sits there for a bit and then the secondary charger kicks in and the amperage ramps up again (79 or 80 amps, depending on the source). The time between the point at which the primary charger reaches capacity and the secondary charger activates has varied for me, sometimes its as little as 10-15 seconds, sometimes its as much as a minute or so.

I have noticed this behavior as well.

 

[Cottonwood]

Moral of the story: after getting a second charger installed, confirm that it is actually capable of charging over 40 amps before you take a trip an discover this on the road.

That is an instance of a conservative rule concerning "stuff" in our world:

If it has not been tested, it does not work!​

I've found that when you plug into a higher amperage charger, the primary charger activates first and ramps up the amperage to its rated (39 or 40 amps). It then sits there for a bit and then the secondary charger kicks in and the amperage ramps up again (79 or 80 amps, depending on the source). The time between the point at which the primary charger reaches capacity and the secondary charger activates has varied for me, sometimes its as little as 10-15 seconds, sometimes its as much as a minute or so.

That mode of operation has been true since I first got a Model S over 3 years ago. If your EVSE (or your screen current limit) can provide over 40 Amps, then the ramp up with dual chargers will be first to half of the final current, pause, then continued ramp up to the final current.

 

[Curt]

Just a note on dual charger operation:

I've found that when you plug into a higher amperage charger, the primary charger activates first and ramps up the amperage to its rated (39 or 40 amps). It then sits there for a bit and then the secondary charger kicks in and the amperage ramps up again (79 or 80 amps, depending on the source). The time between the point at which the primary charger reaches capacity and the secondary charger activates has varied for me, sometimes its as little as 10-15 seconds, sometimes its as much as a minute or so.

Thanks for that!

It explains the behavior I saw when charging a Model S (with dual chargers) from my 70 Amp Roadster HPC, using a TSL01 to TSL02 adapter. At first, I thought it wasn't delivering the full 70 Amps, then it ramped up about a minute later.

 

[sxnahm]

Well, my story of the over-the-air update had a bad ending. Tonight I went down to the car (which I do not drive every day) to check out what happened after the update to enable the second charger. I opened the door, sat down in the driver's seat, depressed the brake... and nothing. Presumably something that happened with the update caused the 12v batter to drain.

I called roadside service and they sent a tow truck out to take it to the local service center. They were not able to revive the 12v by charging it, so they extracted it from the garage with a towbar. They put the front wheels on a dolly once it was out of the garage.

Geesh, I would have been fine with taking it in for the config update that they missed earlier. Now the car has been dragged to the service center. Hopefully it arrives in one piece.

 

[electricjed]

Im sure you all know but I will just point out that the HPWC has DIP switches inside for output configuration options.

 

[sxnahm]

Here is what I was told happened that "bricked" my 85D: The second charger was installed in August, but the service center neglected to configure the car to know that it had a second charger. I eventually figured out that the second charger wasn't working this month, but between August and now I upgraded the car to V7 firmware. When contacted the service center this month, they saw that the second charger was not enabled. Since it was a configuration error, they believed it could be corrected over the air.

When they the sent the update, it killed the car because the firmware in the second charger had not been upgraded when I upgraded to V7 (the car didn't know it was there). I told the service manager that the operating system should have prevented the config change when there is a firmware mismatch (I'm a release manager and have seen this). He then said they did an override to force the config update.

Some lessons for Tesla to learn:

1. TEST new hardware after it has been installed.
2. When the deployment tool tells you it doesn't think it is safe to proceed, bring in an expert who can advise on the next steps.
3. After a major forced update, do diagnostics to ensure that it worked. It was over 48 hours from the update to when I discovered the car was dead. Roadside assistance told me that the car last communicated with the servers a day before. It is possible that the car died immediately when the forced update was done. They should have checked it out.

An additional issue was that the tow service that was sent to get my car, which was in my garage, could not figure out how to remove the nosecone for charging the 12V. The roadside assistance person said the tow company would know exactly what to do. The first person called his company and a second person was sent who quickly removed the nosecone, but after about a half hour delay. But my confidence in the tow company was greatly reduced as a result. After extraction, I pointed out a spot on the front plastic lip where it grazed the garage ramp when the car was extracted. The second driver, who was performing the tow, got huffy, crawled under the car and said there was a lot of scraping from the past. I pointed out fresh plastic strips to him and he left without saying anything more.

I told Tesla about this damage and they said they would replace the part during the servicing.

Looks like I will be getting the car back today, hopefully in 100% better condition!

 

[sxnahm]

Hopefully this is my last post on this incident. When my car was returned on Saturday, I immediately saw that one of the parking sensors was dislodged:

Presumably this happened when they replaced the plastic guard under the nose of the car. The car was washed before being returned to me, surely someone saw this!

I needed the car for the weekend, so the asst. service manager picked it up this morning and returned it tonight. What a series of goofs and mistakes. Hopefully this is not typical of all service centers!

 

[sxnahm]

Okay, so it wasn't the last post. I discovered a second issue that resulted from replacing the plastic underguard. I tried to reinstall my license plate holder, which is the excellent, but poorly named, "The Law". It has a clever bracket that fits on the upper grill, allowing the plate to be mounted without drilling into the nose cone.

My attempted mounting was thwarted because the grill was misaligned, and I saw that mounting clips which should be been holding the grill in place were not in the correct position.

I called the service center and was told that it was actually the nose cone which was misaligned, and they are offering to come out and fix it at my home.

I asked the service manager why this happened and was told: "I and my team were rushing to get your car done and back to you as quickly as possible. Normally, something like this would not happen. I take responsibility for putting abnormally high pressure on my team. I typically favor care and thoroughness over speed, but in this case I gave priority to speed and that resulted in this oversight. I apologize for the inconvenience." I appreciated his frankness, but explained that from my perspective as a customer, care and thoroughness should never be compromised.

 

[SW2Fiddler]

This is the saddest game of Dominoes that I have ever witnessed.