I’m buying my boss’s 2018 MX 100D. While waiting for my wall connector to arrive and be installed, I was over at his place and hooked it up to his gen3 wall connector (I’m charging 110 at home). I was surprised to see it charging at 44 mph. I mentioned to him I thought it would only charge at 30 mph on a gen3 wall connector. He said he thought it received some kind of software upgrade that allowed it. Fast forward to today where I just got my wall connecter installed on a 60A circuit and I’m only getting a 30mph charge rate. Did I imagine the 44mph charge rate? I don’t remember what it said for amps while charging. He’s on vacation otherwise I’d go back to confirm. For reference, he’s got two gen3 wall connectors on a 100A circuit setup for power sharing.
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Charging at 44mph
- Thread starter chinhster
- Start date
ATPMSD
Active Member
When connected to your Wall Connector, what does your car show as amps while charging? If it is not 48 amp the easiest thing to check is if the Wall Unit has been properly configured. Check the manual. And to confirm you have Wall Unit and not a mobile connector, right?
There used to be an option that ended I think in 2018 for a 72amp circuit in model x/s. If your boss has an older wall connector that supports 72amp charging, that’s the difference. It would need to be on a 90 amp circuit breaker.
I'll check. I could swear both of his wall connectors were white like mine so they'd be the gen3.
Unlikely. Back in 2018, the Model X was capable of 72 amp AC charging. Also in that era the Wall Connector was Gen2, which was capable of charging up to 80 amps (when installed on a 100 amp circuit and programmed correctly). Load sharing between two WC, required a data cable between them, while Gen3 uses WiFi. Externally, they look the same.
Since 2018, the X was reduced to 48 amps max, as well as the Gen3 WC only supporting 48 amps max. If you want to check, look at the charging display when NOT connected to a charger. It probably shows 72 amps maximum. Also, ask your boss if there is a cable between his two WCs. Cable = Gen2, (80 amp max), WiFi = Gen3 (48 amp max). Today, you can only buy a Gen3. Back in 2018, you could only buy a Gen2.
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Lot of things to correct here.
Just running a quick ratio of 72/48 amps multiplied by that 30 mph does show about 45 mph, so the 44 mph you were seeing was for the 72A current that the older Model X can take. The previous owner has Gen2 wall connectors, not Gen3 if you were actually seeing 44 mph on the display. But yeah, looking at the amps is a more certain determination.
No, he definitely doesn't. Circuit sharing STILL hasn't been enabled for the Gen3 wall connectors, and it's been well over a year!
They don't look anything alike. The Gen2 ones were twice as big and twice as heavy as the Gen3, and they never made the Gen2 with the white faceplate, which is the only way the Gen3 ones look.
Just running a quick ratio of 72/48 amps multiplied by that 30 mph does show about 45 mph, so the 44 mph you were seeing was for the 72A current that the older Model X can take. The previous owner has Gen2 wall connectors, not Gen3 if you were actually seeing 44 mph on the display. But yeah, looking at the amps is a more certain determination.
Harvey Danger
Member
Yes, my mistake. I’d only glanced at his wall connectors and mistook the silver for white and I hadn’t gotten my gen3 yet to appreciate the size difference. I also thought the gen2 wall connectors were black due to the one time I searched for wall connectors on eBay weeks ago and a whole bunch of what I now know to be gen2 signature edition listings were returned with the gen3’s.
I’ve driven more in the past few weeks since I’ve gotten the MX than the few months prior and the overnight 48A charging has been more than adequate but a part of me wishes I was more knowledgeable at the time and maybe installed a gen2.
Harvey Danger
Member
And voila just a few days later we have this:
Wall Connector Power Sharing | Tesla Support
With Power Sharing, you can allow up to six 3 Wall Connectors to share power and charge multiple vehicles at once. Learn how to set up and troubleshoot Power Sharing.
thtrotter
Member
I have a late 2017 MX 100D and for years I have been using my Tesla wall charger connected to two 80amp breakers. It would say 64/64amp and charge at 40mph. Suddenly, today, it says 48/64amp and will only charge at 31mph?! WTF?! I did nothing different!
Any ideas?
Any ideas?
ATPMSD
Active Member
thtrotter
Member
I'm confused. You have a X, with I'm guessing the 72amp charger installed. You have a Gen 2 HPWC also, hooked to dual(??) 80amp breakers? I'm guessing you mean just hooked up to with a single 80amp breaker.
Then you show a photo of your charging screen, with 64amps as the max available charge rate.
So I'm guessing we are missing some information, or your HPWC has it's dip switch setting wrong to begin with (if you really are on a single 80 amp circuit).
Beyond that, your onboard charger might have a fault. There are 3 (I believe) boards inside the internal charger. One might have failed.
You are using words that don't make any sense here. It's a 240V circuit, so it uses a two pole breaker instead of a one pole breaker, as a 120V circuit would use. There is no single circuit or double circuit.
@thtrotter I was also inclined to think the same thing that @ATPMSD was saying about possible voltage drop. There is a system in the car that will look at the starting voltage before charging and compare it to the voltage when it has ramped up charging with a heavy load, and if there is excessive voltage drop from that, it will reduce the charging amps to three fourths of what it was to see if that helps. That is what the 48/64 amps seemed to indicate.
But you do show 243V when charging, which should be totally fine. I am wondering if there was some very short term voltage sag in your neighborhood that triggered this. If it has kicked in this lowering, I don't think it will automatically go back up until you turn it back up on purpose on the screen. Does it let you adjust the amps now?
OK it was late when I posted that and re-reading it today it dawned on me that 80% of a 80amp breaker is 64amps.
A: I had my head in 100amp breaker world (80% = 80amps) so now I get why the photo's show what they do.
B: I also was thinking of two, physical breakers, as in 100amps X 2.
C: Yea, the whole 120/240 single/double pole breaker part, but it is still physically one unit on a double pole breaker, even though it's technically 2 120's together.. I was just thinking of literally two separate complete breakers.
D: Fiver shouldn't be online after midnight. Mistakes were made lol. Although I stand by my comment about the possibility of an internal board failure inside the onboard charger. The voltage thing is also a possibility as mentioned above. Perhaps something else in the house is kicking on and momentarily dropping the voltage in the home enough to have the HPWC dial back.
As it turns out, I believe an error code was revealed in another thread that indicates this is most likely the issue.
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