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New UMC 14/50 limited to 32 amps... WHY?!

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SabrToothSqrl

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Dec 5, 2014
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Tesla releases 40% cheaper next-gen mobile connector for Model 3, S, and X

So if my original one breaks I'm stuck at 32 amps? with my 40 amp charger?

Why....?!

if I plug my wife's Model 3 into MY existing UMC... will it hit 40 amps?

If I plug my S into her UMC, it will only hit 32 amps?

Now, personally this ticks me off, but realistically, with my rural location, and mediocre power, I've only ever been able to sustain 34-35 amps anyway... 32 isn't far off, but what the dilly?!
 
If your wife's Model 3 is Long Range, yes it will charge at 40 amps with the Gen 1 Mobile Connector. My guess is the original Mobile Connector had more failures than they originally accepted so they can bring costs down with the 32 amp version with the different style of plug adapters. Additionally more people may decide to go with a Wall Connector since you would get 50% faster charging at 48 amps instead of 32. The Wall Connector is safer and more reliable than the Gen 1 Mobile Connector.
 
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If you search this forum for melted UMC connectors, you may have your answer to your question on the power reduction. The previous generation of UMC was designed in such a way with the removable plugs that you could get a poor connection. Coupled with a 40 amp output, that was a recipe for overheating. How many times were the plugs recalled and redesigned? Twice? That's some serious liability to sell a product that has heating/melting issues like that...I haven't seen the new generation unit yet, but I'm betting it runs cooler, and isn't prone to coming out of the wall receptacle as easy, etc...
 
In addition, North America does not have a 40A receptacle, it only has a 30A or a 50A receptacle. This means that you have a fair amount of 50A receptacles out there that only have 40A wiring a 40A breaker (this is allowed in the electrical code). Most people don’t go to the trouble of checking the breaker size when they see a 50A receptacle (I’m talking reuse of an existing receptacle that had previously been installed for a welder or range, etc.), so this results, over the entire fleet, in many dangerous charging sessions.

Blame the NEMA if you want to blame someone.

While I always like to charge at the highest rate possible, there are very, very few situations where charging at 32A wouldn’t work just as well as charging at 40A. The vast majority of the time, these charges will be overnight, and 32A is going to fill your battery just fine.

I also agree with CmdrThor, and I would even go a step further. IMHO Tesla made a big mistake when they (and still do to some extent) recommend that people just use their mobile connector for daily charging. The Wall Connector is MUCH more robust and has a lot of features you’re going to want if you get a second EV. I would recommend that you get a Wall Connector regardless, and stick the mobile connector in your trunk.

Btw, I commend Tesla for finally fixing the mobile connector. The first generation had a lot of safety problems - their detachable plug mechanism just wasn’t designed robustly enough. This new gen 2 system looks great. AND they finally have adapters for SIX plug types. Finally!!!
 
Interesting... I've thought about a HPWC, as I would charge at 80 amps, but I can't justify the cost/install hassle.
35 amps meets my needs, and 32 would most likely as well, just don't like feeling like we are going the wrong direction in charging speeds.

Does this mean that if I buy a new 100D, today, it would charge at 32 amps?
 
Interesting... I've thought about a HPWC, as I would charge at 80 amps, but I can't justify the cost/install hassle.
35 amps meets my needs, and 32 would most likely as well, just don't like feeling like we are going the wrong direction in charging speeds.

Does this mean that if I buy a new 100D, today, it would charge at 32 amps?
The car itself should be able to charge at 40 amps with the Gen 1 UMC, up to 48 or 72 amps with the HPWC. We just took delivery of another car last week and it still came with the Gen 1 UMC and can charge at 40 amps. There's chances that deliveries for the next couple weeks will still include the Gen 1 UMC.

We usually only charge at 32 amps anyways so the Gen 2 UMC would've been fine for us. I was actually kind of wishing we'd get the Gen 2 UMC since we have a set of the Gen 2 adapters and could finally use our 6-20 outlet with an official Tesla adapter. It would only have been short term anyways because we'll probably be installing the signature HPWC from the referral program in the coming months.
 
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Yeah, I suspect the UMC will be identical, but it will be limited to 32a. I have had a discussion in another thread about the power delivery instability of current UMCs and their failure rates at 40a. People are arguing with me, but this only confirms that fact that the UMC simply can't handle a daily 40a rate and remain a) stable and b) not break sooner rather than later.

Limiting the current UMC to 32a would resolve the issue I believe.
 
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Tesla releases 40% cheaper next-gen mobile connector for Model 3, S, and X

So if my original one breaks I'm stuck at 32 amps? with my 40 amp charger?

Why....?!

if I plug my wife's Model 3 into MY existing UMC... will it hit 40 amps?

If I plug my S into her UMC, it will only hit 32 amps?

Now, personally this ticks me off, but realistically, with my rural location, and mediocre power, I've only ever been able to sustain 34-35 amps anyway... 32 isn't far off, but what the dilly?!
The mobile charger was really pushing the limits at 40 amps and had a lot of failures and overheating.
Makes sense to limit it to 32 amps.
BTW, I installed a HPWC but only charge at 32 amps since it's more efficient and I never have a problem gaining a full charge overnight.
 
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I was expecting them to continue delivering Model S/X with the Gen 1 UMC and the Model 3 with the Gen 2 UMC, thus I'm a bit surprised by the report that all vehicles will be delivered with the Gen 2 UMC.

I got used to charging my S75 nightly with the J1772 adapter and a GE WattStation that I used with my previous/other plug-ins (since it took forever for Tesla to restock the NEMA 6-50 adapter and I didn't want to swap out my outlet for the 14-50 when I took delivery).

It is nice that they at least offer the 6-15 and 6-20 adapters for the Gen 2 UMC for those who need it. I needed to charge on a 6-20 outlet for a few months, and ended up just buying a TurboCord to use for my needs since I was unable to track down a 6-15 adapter for the Gen 1 UMC.
 
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Yeah, I suspect the UMC will be identical, but it will be limited to 32a. I have had a discussion in another thread about the power delivery instability of current UMCs and their failure rates at 40a. People are arguing with me, but this only confirms that fact that the UMC simply can't handle a daily 40a rate and remain a) stable and b) not break sooner rather than later.

Limiting the current UMC to 32a would resolve the issue I believe.

If there is a reliability issue with the Gen1 UMC(I've had none with mine and daily 40A charging), I don't see how the required resolution to that is to limit the new UMC to 32A. It must be possible to build a robust UMC that supports 40A. Tesla chose not to do that.

Pushing more owners to the Wall Connector is clearly part of this strategy. It would have cost me an additional $1100 to have a WC rather than simply use the UMC with a NEMA 14-50 plug.
 
I have had a discussion in another thread about the power delivery instability of current UMCs and their failure rates at 40a. People are arguing with me, but this only confirms that fact that the UMC simply can't handle a daily 40a rate and remain a) stable and b) not break sooner rather than later.
Well if you would have actually started off saying what you meant (that it doesn't handle running at 40A consistently) rather than just calling it an unstable power delivery device, period, then people wouldn't have had to argue with you.
 
Well if you would have actually started off saying what you meant (that it doesn't handle running at 40A consistently) rather than just calling it an unstable power delivery device, period, then people wouldn't have had to argue with you.

If you wouldn't take the discussion out of context and cherry pick my sentences to support your flawed position, we wouldn't have an argument, either.

Is the UMC rated to handle 40a? Yes
Can the UMC sustain it's rating? No
Conclusion: UMC is an unstable power delivery device. Simple logic.

The UMC is an unstable power delivery device. Period. It's rated for 40a, it can't consistently deliver 40a. It's unstable. My statement stands. Your statement is incorrect (which basically boiled down to: Well it works at lower power, so it's not unstable.)

Hey, I have this stool, it's supposed to have 4 legs, but only 3 legs can support any weight. If you sit just right, it's perfectly stable. Nobody in their right mind is going to call that stool stable.
 
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Tesla releases 40% cheaper next-gen mobile connector for Model 3, S, and X

Why....?!

Now, personally this ticks me off, but realistically, with my rural location, and mediocre power, I've only ever been able to sustain 34-35 amps anyway... 32 isn't far off, but what the dilly?!

Residential EVSE: Charging Stations for residential use | ClipperCreek

So looking here for the ones with a 14-50 plug we have

* 12amp at $379
* 16amp at $395
* 20amp at $485
* 24amp at $515
* 32amp at $589
* 40amp at $659

If there wasn't a cost difference they'd just build them all the same and slap a different label on them (swap one component or use a dip switch or something to advertise a lower charge rate). Just like Tesla selling a software limited pack (60/75 and such).

The clear and simple reason is right in the headline. 40% cheaper.

The fact that Tesla will sell you a 32 amp for $300 including adapters is game changing for price conscious buyers. Its half the price of some of the retail equivalents.

Model S/X/3 Mobile Connector Bundle (Shop.Tesla.com)

Includes:

  • 1 x Mobile Connector Main Unit (with 20 ft cable)
  • 1 x NEMA 14-50 Adapter*
  • 1 x NEMA 5-15 Adapter
  • 1 x Storage Bag"
*The second generation mobile connector has a max output of 32 amps when using the 14-50 adapter.
 
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