It doesn't have any what is plugged in. All it knows is that something is plugged in telling the car that it can provide 40 amps. There is no way for it to tell whether it's an old UMC or an old HPWC.
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It doesn't have any what is plugged in. All it knows is that something is plugged in telling the car that it can provide 40 amps. There is no way for it to tell whether it's an old UMC or an old HPWC.
Canuck
Well-Known Member
Yes, I know that. I also own a Leaf and my Tesla can charge up to 80 amps -- something that is no longer available on any new Tesla.
But my car will dial down amps by itself if it doesn't like the connection and Tesla has made it much more picky when it comes to dialling down amps right after the garage fires a couple of years back. There's long threads here about that. So I can see it as a possibility that Tesla won't want want people using old UMCs to charge their 3's at 40 amps since a number of old ones will come on the market, especially from salvages vehicles, etc. If it's possible to do, I see it as possible that Tesla could tell the car to only accept 32 amps.
Well that's good news to know. Thanks. I guess @ccutrer was telling me the same thing and it's not even a possibility that it won't work. That's good news.
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diamond.g
Active Member
ccutrer
Active Member
Ok riddle me this then - standard model 3 is 32A charger. LR Model 3 is 40A charger. We know both vehicles come with a UMC limited to 32A (which still seems weird to me since they already have a 40A capable UMC they could throw in with the battery upgrade). We also know a car cannot distinguish between a legacy UMC or some other 40A+ J1772 EVSE (such as a HPWC, as is deployed at thousands of destination charger locations). Given all that, why on earth would Tesla artificially limit charging to 32A from a 40A EVSE and at the same time advertise 40A charging on the LR model?! I know you're worried that Tesla wants to play it safe on 14-50s that are actually on 40A circuits, as they have shown themselves to do so in the past in Canada, but I feel that the Canadian 14-50 for old UMC, and new UMC is always limited to 32A -- the two ways of charging at home that are provided with the vehicle -- so it would actually break charging on legitimate stations (especially their own destination charging network) to try and outsmart people using old UMC at a true 40A. Heck they'll probably use it as an upsell opportunity to sell you a CMC, or a wall connector (giving them more reason to not artificially break it).
Canuck
Well-Known Member
This is what I didn't know so thanks for educating me. It all makes sense now and #1 is out, even as a possibility.
ccutrer
Active Member
Cool, we're all on the same page then. Maybe if old UMC had digital communication it would be a possibility to detect it vs. any other 40A J1772, it would be possible to block 40A charging in that one case, but still weird.
Honestly I can't wait to get my hands on a new charger and try different combos of EVSE and car, even if only to go from 80% certainty to 100% certainty of how things work in real life.
Tam
Well-Known Member
I didn't know Canada restricts your older UMC adapters currently to a maximum 32 A on your Model S/X.
I would expect the same restriction on your new Model 3 regardless new or older UMC.
I'm more looking forward to getting my hands on the new car.
(btw, my Model S long ago reduced my charging to 32 amps on my 14-50. It's fast enough, so I've never looked into it.)
ccutrer
Active Member
Well that too... I've got to build a house first, which means I'm forgoing my earliest delivery opportunities unfortunately. If the stars align, I can have the house done by spring, and an AWD 3 delivered by summertime.I'm more looking forward to getting my hands on the new car.
Maybe the LR Model 3 will come with the S/X UMC instead of the new lower power Model 3 UMC.
ccutrer
Active Member
Yeah it's possible that could change when we get to customer deliveries, but what we've seen so far is only LR Model 3s, with the new UMC.
Does the older S/X UMC require 50amp circuit or is it smart enough to dial it down ? I am ordering a LR and have 6-50 outlet on a 40amp breaker (left over from my Leaf days).
I doubt it. I think the new charging cable is a cost saver. Feel lucky, I'm pretty sure the Bolt only ships with a 110v charging cable.
Canuck
Well-Known Member
I don't know about the Bolt but that's all my 2012 Leaf came with when I got it.
ccutrer
Active Member
No it doesn't. I use my Canadian 14-50 when I'm at my parents house that have a 14-50 on a 40 amp breaker. A 6-50 on a 40A would require you to dial down to 32A manually in the car. But since you'll have new UMC that only does 32A, it won't matter.
Tam
Well-Known Member
It dials your car's charging setting according to which adapter you connect to it.
So if someone placed a 50A outlet on a 30A breaker circuit, it is not smart enough to know that this is not a 50A circuit and it would set your car charging setting as if it's on a 50 A circuit which would blow the fuse or start a house fire.
That's good to know. I asked a MS owner if there was way to set current rate from the car, he said no, only the depth of charge. I guess he did not know.
That mean you CAN use 32 or 40 amp UMC on a 40 amp breaker.
I also found this on current S/X 40-amp UMC's user manual:
"Use only a 120 volt, 208 volt or 240 volt AC supply, 50/60 hertz wall outlet that has a dedicated and properly grounded circuit, and is rated for at least 15 amps."
Does not say that you are required to have a minimum of 50 amps circuit. Looks like it dials the charge rate down, automatically or manually.
https://www.tesla.com/sites/default/files/Mobile_Connector_Touchscreen_NA_R20160317_en_US.pdf
Canuck
Well-Known Member
How it works is your charging screen will have your maximum amps shaded out. In my vehicle, it's 80 amps. But when I plug in my UMC, my shaded out 80 amps will change to 40 amps without being shaded and the car will start to charge. I can dial down the 40 but not up. When I plug into my Clipper Creek 48 amp EVSE for our Leaf, it shows 48 amps that I can dial down but not up.
I also have HPWCs at home and at my cabin. At home, because I don't need 80 amps for overnight charging, I dial down the amps to 42 so each of my dual chargers share the load at 21 amps each (they are a liquid cooled high wear item so my theory is less amps = less heat = less wear). After I dial it down once, it will remember that setting and location forever so I have to dial it back up if I want to charge faster. It's never forgot the dialed down setting once for me, even after taking updates and rebooting, but others have said it does.
For the Model 3 remember we also do not have confirmation on the premium charger. The PR materials talk about 40 Amps but that could just be the normal 14-50 available Amps). One TMC user has an email from the charging group at Tesla that said the charger in the PUP Model 3 (all current cars) is actually 48 Amps.
So we need someone with a car (and employees probably won't do this) to plug one into an HPWC and see what we get.
So we need someone with a car (and employees probably won't do this) to plug one into an HPWC and see what we get.
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