"Unable to Charge" Errors Appearing Mysteriously. Is Software to Blame?

[lardlad00]

I recently took a road trip in my 2016 Model S 75D. Before leaving for the trip I decided to top off at my office charger, a Clipper Creek 60-amp with a J1772 connector. When I plugged in I noticed an "Unable to Charge" warning on the dash, but it throttled up and started charging anyway. It topped off at 24amps, however, instead of the 48 that it was capable of.

I assumed something was wrong with the charger and went on my way. However, at the hotel I stayed at I noticed the same issue on their destination HPWC. It wasn't a big deal because I had all night to charge, but still, strange. I wondered if it was just a coincidence as hotel chargers can be a little rough. Returning home, however, I found that I was getting the same error on my home HPWC and figured it was a problem with my car. Who knows how long it has been a problem, because I charge all night and there is plenty of time to get a full charge at 24amps.

Supercharging worked fine throughout the road trip.

I made an appointment for mobile service and the tech messaged me and said everything was checking out on their end. He encouraged me to do more testing, and lucky me, I also have a Model X at home. I tried that on my other charger and sure enough, a very similar issue. I was getting the error but the car would still throttle up and charge full speed. At that point I cancelled the appointment and figured I'd test some more. Not long after I had an electrician at my house for a different project and I asked him to check out my chargers. He took a look and was satisfied that everything was hooked up correctly, but admitted he did not have any expertise on the chargers. We both left figuring there might be something wrong with the HPWC units themselves (I have two and both were causing the issue).

As a last test I decided to go out and find another L2 charger nearby and found that I was still getting the same issue. At that point I was convinced that there was something wrong with the car, but what are the odds that both of my Teslas encountered the same issue at the same time? I began to suspect a recent software update might be to blame.

I've been researching and have noticed several other people with this issue popping up lately. I wanted to start this thread to try to collect them in one place and see if we can figure out what we all might have in common. See these related discussions:

Am I the only one getting false unable to charge message | Tesla
"Unable to Charge open charge port and press brake pedal and try again" | Tesla
Unable to charge disconnect cable and retry message
"Unable to charge - Disconnect cable and retry" - fixed

Could this all be related to recent updates regarding the fire in Shanghai?

Tesla Model S Shanghai Fire, Range, And Charge Issues Seem Connected

Tesla pushes battery software update after recent fires

I suspect that the cars are now much more sensitive (too sensitive) to voltage drops when charging starts.

Anybody else?

 

[boaterva]

I get this sometimes in the summer when the local power company cranks up the voltage to compensate for everyone running air conditioning. The X won’t charge from high voltage. The 3 has no problem. I’m about to contact Tesla when both are home charging to see what’s different about the X’s charger that it’s less tolerant. Weird that one car loves it and one rejects it.

Wonder if you’re running into this problem?

And, yeah, pretty sure this is it. My solar inverter shows 248 and 249 VAC. And before anyone blames it on that, it happened last summer when all I had was the X. When it drops to 245 or 244 the car eventually decides to accept the power. The app right now shows a red charge port and ‘Check Power’. The 3 shows no issue at all.

 

[zanary]

When the warning occurs do a Bug Report and then call Tesla and tell them to look at the logs. That might show more.

 

[spacklewoof]

My 2012 model s with dual chargers was charging much slower (12 vs 24MPH) than normal last night after upgrading to 2019.20.4.3

 

[SMAlset]

You know my husband was on 2019.20.4.2 on his MS and then got the 20.4.3 update within a few days of receiving 20.4.2. I remember him telling me about getting a charging alert when he was charging at work. Prior to this no issues. Another time he was charging since then I was looking at his car on the app and saw the charge port go red before going green when he went to plug in. We talked about it then. He was wondering if he was going to need a service call but so far he's been able to charge. Don't know if he looked at any of the charging details.

 

[lardlad00]

Wonder if you’re running into this problem?

I don't think it's a high voltage problem. I actually think that it's a problem with fluctuating voltage, and I think in a recent update (perhaps 20.4.2) they made the system much more sensitive to shutting down the charge for certain voltage drops.

I watched it with my electrician to get his feedback. On plugging in, my car showed a voltage in the 242, 243 range. When the amps start cranking up, the voltage was dropping down to the 235 range. My electrician didn't find anything alarming about that for my setup, and assured that such a drop is to be expected and well within acceptable parameters (in general). I think, though, that this software version has been set to be very sensitive to this and is taking the voltage drop as a sign of problematic charging setups, likely as a result of recent precautions.

My 2012 model s with dual chargers was charging much slower (12 vs 24MPH) than normal last night after upgrading to 2019.20.4.3

What did you have before 20.4.3? I'm on 20.4.2 and I first noticed the problem the day I did that upgrade

You know my husband was on 2019.20.4.2 on his MS and then got the 20.4.3 update within a few days of receiving 20.4.2.

Can you find out if he's still having the issue on 4.3 or was it just a 4.2 thing?

 

[SMAlset]

Can you find out if he's still having the issue on 4.3 or was it just a 4.2 thing?

I looked back to see if I had a photo of when the port was red for a brief moment when it happened (was looking at the app of his car while we were talking and he had started to plug in at work) but didn’t. I’ll ask him if he took a photo of the alert on his car’s instrument screen, sometimes he does. Phone would date the photo. I asked him earlier tonight about this in general, he’s at work now or would call and ask, and he did recall it happening and said he hasn’t seen the alert again. If not mistaken it was the “unable to charge, disconnect the cable and try again” message mentioned above.

 

[Redmiata98]

I had a similar error and rebooted with no change, car would not charge properly from my HPWC. It said I needed to unplug and reconnect but the touchscreen showed it was charging VERY slowly (5 mph vice the 40+ normal). I called Tesla and they had me do a complete power down via the touchscreen, wait 5 minutes and then start the car. The error stopped and charging has been fine since then. Seems that a reboot or going into deep sleep does not clear all of the nits out of the system like a complete power down does. Try doing it and it “might” work.

 

[MattMatt]

I'm also having this problem on higher voltage chargers. My work has 240VAC chargers, which my car won't charge at all on anymore. If I got to the 208VAC chargers it will always charge.

 

[CAF]

Pretty bas

I recently took a road trip in my 2016 Model S 75D. Before leaving for the trip I decided to top off at my office charger, a Clipper Creek 60-amp with a J1772 connector. When I plugged in I noticed an "Unable to Charge" warning on the dash, but it throttled up and started charging anyway. It topped off at 24amps, however, instead of the 48 that it was capable of.

I assumed something was wrong with the charger and went on my way. However, at the hotel I stayed at I noticed the same issue on their destination HPWC. It wasn't a big deal because I had all night to charge, but still, strange. I wondered if it was just a coincidence as hotel chargers can be a little rough. Returning home, however, I found that I was getting the same error on my home HPWC and figured it was a problem with my car. Who knows how long it has been a problem, because I charge all night and there is plenty of time to get a full charge at 24amps.

Supercharging worked fine throughout the road trip.

I made an appointment for mobile service and the tech messaged me and said everything was checking out on their end. He encouraged me to do more testing, and lucky me, I also have a Model X at home. I tried that on my other charger and sure enough, a very similar issue. I was getting the error but the car would still throttle up and charge full speed. At that point I cancelled the appointment and figured I'd test some more. Not long after I had an electrician at my house for a different project and I asked him to check out my chargers. He took a look and was satisfied that everything was hooked up correctly, but admitted he did not have any expertise on the chargers. We both left figuring there might be something wrong with the HPWC units themselves (I have two and both were causing the issue).

As a last test I decided to go out and find another L2 charger nearby and found that I was still getting the same issue. At that point I was convinced that there was something wrong with the car, but what are the odds that both of my Teslas encountered the same issue at the same time? I began to suspect a recent software update might be to blame.

I've been researching and have noticed several other people with this issue popping up lately. I wanted to start this thread to try to collect them in one place and see if we can figure out what we all might have in common. See these related discussions:

Am I the only one getting false unable to charge message | Tesla
"Unable to Charge open charge port and press brake pedal and try again" | Tesla
Unable to charge disconnect cable and retry message
"Unable to charge - Disconnect cable and retry" - fixed

Could this all be related to recent updates regarding the fire in Shanghai?

Tesla Model S Shanghai Fire, Range, And Charge Issues Seem Connected

Tesla pushes battery software update after recent fires

I suspect that the cars are now much more sensitive (too sensitive) to voltage drops when charging starts.

Anybody else?

Pretty basic, but have you thoroughly cleaned all the contact points on the car and the connector with q tips and isopropyl alcohol? I've had similar issues if contacts are dirty.

 

[jimmythefrack]

My X has been at the service center twice in the last 2 weeks the second time they kept it and have had it for a week with the same issue. They've said they're escalating it but I was able to provide documentation with specific dates, times, and screen shots from 2 different wall connectors that supported 72 amp charing as well as my UMC. The 2 wall connectors were in 2 different states with 2 different power companies (1 in NJ and 1 in VT) the UMC was in Long Island NY and all received the same error. I even tried from the clipper creek j1772 charger in my mother's condo and still had the issue. I'm currently in a holding pattern with service but every time this happened the charging amps always dropped to either 47 amps (wall connector) or 30 amps (UMC) without ever having an issue at any of the locations previously. The first time they had this issue they changed the charge port which looked like it fixed it for a day for some reason maybe just because I didn't charge for long enough to have the drop out but when the car charged for an extended period of time (more than 10 - 20 minutes) the warning message appeared. I'll reply back when I hear from the SC and see what they have to say. I had originally thought there was an issue with the on-board charger because it would drop down from 72 to 47 amps figuring 1 of the 3 boards in the charger was going but the SC didn't seem to think so. Of course that was a week ago so we'll see.

 

[spacklewoof]

I don't think it's a high voltage problem. I actually think that it's a problem with fluctuating voltage, and I think in a recent update (perhaps 20.4.2) they made the system much more sensitive to shutting down the charge for certain voltage drops.

Can you find out if he's still having the issue on 4.3 or was it just a 4.2 thing?

Previous to Friday, I was on 2019.16.2, upgraded @ 5/24

 

[jimmythefrack]

I heard back from the SC today and they told me it wasn't drops that were causing this but spikes. They said what was happening was the internal charger would detect a spike the 3rd charging board would automatically shut down the charger and then only continue at 47 amps which doesn't make a lot of sense. Does anyone have a product they like to monitor voltage and amperage and log the data? I know there are a lot of home monitors that will monitor amperage but Tesla is claiming a voltage spike not a drop. I've tested in 3 states 3 different power companies and I'm having trouble buying the voltage spike thing. I'd like to be able to plug the car in monitor the 100amp 240v circuit its on and when the message appears be able to prove there isn't any kind of a spike or drop in voltage.

 

[boaterva]

Well, this is what I reported. High voltage seems to affect the older chargers. I’m calling Tesla tomorrow because my X still isn’t charging and the 3 works just fine.

 

[jimmythefrack]

I'm going to borrow a fluke meter from my brother and log a charging session when I get my car back I'll post the results but I'm willing to bet there isn't a voltage spike like they're suggesting

 

[spacklewoof]

I see fluctuation from 240 to 247 volts. Percentage wise, that is on the order of about 3%. (2.8)
I charge at night because it's coolest and I get a killer break from the utility. (Mostly because of the utility)
I've seen elsewhere that the voltage in Arizona is "cranked" at night to compensate for AC units coming on and off, to compensate for the loss of other power at night. But "Cranking" and 2% don;t exactly mix.
I'm sure the truth is out there somewhere (queue xfiles theme)

t

 

[jimmythefrack]

I see fluctuation from 240 to 247 volts. Percentage wise, that is on the order of about 3%. (2.8)
I charge at night because it's coolest and I get a killer break from the utility. (Mostly because of the utility)
I've seen elsewhere that the voltage in Arizona is "cranked" at night to compensate for AC units coming on and off, to compensate for the loss of other power at night. But "Cranking" and 2% don;t exactly mix.
I'm sure the truth is out there somewhere (queue xfiles theme)

t

What device are you tracking the voltage with or are you just watching it on the car?

 

[animorph]

I've seen, and charged, at as high as 253V last year with the 2017 X. I haven't been that high recently, so it could still be a recent FW problem. My last >250V was 6/7/2019 with FW 2019.16.2, 248V average, 252V max per TeslaFi.

 

[spacklewoof]

@jimmythefrack I was looking at the voltage numbers displayed in the car.

 

[boaterva]

I've seen, and charged, at as high as 253V last year with the 2017 X. I haven't been that high recently, so it could still be a recent FW problem. My last >250V was 6/7/2019 with FW 2019.16.2, 248V average, 252V max per TeslaFi.

Interesting you’ve been successful at 250+. Mine usually fails around 247-249.

And of course last night mine recovers and charges all night. Usually takes about 24 hours at normal-ish voltage to restart.

If it happens again, I’ll call in. Definitely not a firmware issue on the overvolt since I’ve had this both summers I’ve had the car.