Comparison of Mobile Connectors (for those new to Tesla)

The longstanding Tesla Generation 1 Corded Mobile Connector (CMC) now seems to be officially and truly dead (on the Tesla-USA website). While TMC members are generally knowledgeable about such things, I've seen a great deal of misunderstanding about the various Tesla mobile connectors among the general (e.g., Reddit and Craig's List) population. This post can serve as a handy Internet information source to educate people claiming, for example, to have a CMC for sale (when indeed they do not), and for those readers new to the whole Tesla charging-cable experience.

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The following table provides a comparison of the mobile connectors offered by Tesla-North America over the years.

Notes:

• (Gen2 MCs may also be referred to as "UMCs," but I chose to limit the use of the "UMC" acronym solely to the Roadster and Gen 1 devices, for convenience and to reduce confusion.)
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• This information assumes that the mobile connectors are unmodified (in stock condition) and are not attached to any kind of (aftermarket) wall-outlet-changing adapters or extension cables. (As pointed out in Post #3 below by @Rocky_H, a CMC could probably be used to charge with 120-yolts AC if some sort of adapter were employed. But that kind of defeats the whole purpose of the originally quite expensive and somewhat faster charging 240-volt CMC though, correct?)

Comparison of Tesla North American Mobile Connectors

Click on the Table to enlarge.
(For more on history of Tesla charging equipment, see this post.)


Photos

Original Roadster 240v MC (~2009)
Notice one-piece design, NEMA 14-50 (Hubbell-
manufactured?) plug. (An early precursor to the later CMC?)

Original Roadster UMC (~2010)
Notice two-piece design, beefy (also
Hubbell-manufactured) NEMA 14-50 plug.

Gen1 UMC
Note adapter plug type, slightly different controller appearance,
and circular bag (underneath) as compared to Gen2 MC.

So to further help differentiate CMCs from Gen2 MCs:

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[Soul Surfer]

I will never part with my mobile charger. Saved my bacon a few times.

 

[Rocky_H]

@tps5352 I probably would not have those line items about whether they can use 120V or 240V supplies, because I am certain all versions of them can use either of those, so that is some inaccurate information you have in there. If someone used a plug changing pigtail to make a 5-15 plug to 14-50 receptacle to use with the Corded Mobile Connector, I am sure it could still use that 120V outlet. It's just not physically built to make the plug fit.

 

[Gordon87]

I have wanted to purchase the Corded Mobile Connector but it is always "Out of Stock." I wonder if or when it will ever be available for purchase.

 

[tps5352]

I have wanted to purchase the Corded Mobile Connector but it is always "Out of Stock." I wonder if or when it will ever be available for purchase.

Me too, along with many others I suspect. However, my previous unscientific poll suggests that relatively few people use the CMC as compared to Gen2 MCs and Tesla wall connectors. That may have been an artifact of the ridiculously high original price ($520). Now that the CMC is a much more reasonable $200 price, more people may want to use one as a home charging cable (semi-permanently plugged into a NEMA 14-50 wall receptacle). Ironically, this is when we see them out-of-stock on an almost a continuous basis at Tesla.com.

 

[wws]

Tesla offered either a 6-15 or 6-20 adapter for the Gen 1 UMC for a while. I _think_ it was 6-15. Unfortunately none of the Gen 1 UMC adapters appear in the Tesla Store anymore.

 

[tps5352]

I've added information about the original Roadster UMC to the table in the OP. Since I know less about Roadsters and their accessories, I'd be glad to hear from Roadster owners confirming or correcting this info. In particular, was there a (circular?) carry bag for the Roadster UMC?

 

[Genie]

I have wanted to purchase the Corded Mobile Connector but it is always "Out of Stock." I wonder if or when it will ever be available for purchase.

Because of the extra ( <2kW )charging rate?
If that is not a must-have, for an extra $30 the gen2 UMC is a lot more versatile and not currently on backorder.

 

[tps5352]

Because of the extra ( <2kW )charging rate?
If that is not a must-have, for an extra $30 the gen2 UMC is a lot more versatile and not currently on backorder.

Agreed. However, the CMC is:

• more rugged (one piece and heavier cable)
• convenient if you are using a NEMA 14-50 receptacle at home (can leave plugged in and keep the Gen2 MC in the car)
• faster (with its somewhat higher maximum amperage)

For many years--when it cost $520--it just didn't make sense to buy one, since the Gen2 MC and NEMA 14-50 adapter plug together were so much less expensive.

Now that it is only $200, it makes perfect sense as a second charging cable--to use for garage charging at home or maybe on the road where there is a NEMA 14-50 outlet.

Still not for everyone, but great for people who regularly use a NEMA 14-50 source. So, of course, it is usually unavailable from Tesla. ???

 

[bmah]

Agreed. However, the CMC is:

• more rugged (one piece and heavier cable)
• convenient if you are using a NEMA 14-50 receptacle at home (can leave plugged in and keep the Gen2 MC in the car)
• faster (with its somewhat higher maximum amperage)

For many years--when it cost $520--it just didn't make sense to buy one, since the Gen2 MC and NEMA 14-50 adapter plug together were so much less expensive.

Now that it is only $200, it makes perfect sense as a second charging cable--to use for garage charging at home or maybe on the road where there is a NEMA 14-50 outlet.

Still not for everyone, but great for people who regularly use a NEMA 14-50 source. So, of course, it is usually unavailable from Tesla. ???

Yep, my use case is that I have a NEMA 14-50 outlet in my garage, and I wanted a plug-in charger to just stay there semi-permanently, while the mobile connectors (plus adapters) go in the cars on road trips. I've had that outlet for years and have zero need or desire to turn that into a wall connector. I was lucky to snag a CMC when they were briefly available last year.

Bruce.

 

[E90alex]

Word of caution, my 40A CMC started overheating in less than a year and it was dialing back on amperage to like 27-28A at its lowest with plug temps in the 130°F range.

There seems to be some anecdotal reports of some Gen 1 UMC overheating as well, of which the CMC is based on. Not sure how common of an issue it is since the CMC is already very rare as it is. YMMV, but possibly not worth the trouble to seek one out over the seemingly more reliable Gen 2 UMC.

 

[tps5352]

Word of caution...

I would add this...

Over the years there have been reports (here on TMC and elsewhere) of issues using the NEMA 14-50 wall receptacles. As near as I can tell, most of the problems have been due to using cheap (~$15) wall outlets (yeah, I'm talking about you, Leviton) and/or not tightening down the connectors properly. The much more expensive, but also much more well made, Hubbell/Bryant receptacles tend not to experience those problems (e.g., arcing) as it is easier to torque the connection screws down properly with the beefy Allen/hex bolts provided. (These issues can arise even for people who used professional electricians and who paid the extra "Tesla tax.")

Now it may be that CMCs have had issues, I don't know. But the very first thing I would do is to turn off the power and check the installation of whatever NEMA 14-50 wall outlet you have. Check for obvious signs of arcing. If there are no problems with the wall receptacle, and assuming you have the proper gauge of house wire (e.g., #6) and everything else (proper 50a GFI circuit breaker) about your house circuit is OK, then the CMC may indeed have a problem. Another obvious diagnostic tool would be to try and charge using a different cable, like the MC with a NEMA 14-50 adapter-plug, preferably one that can operate at 40a, which the MC cannot do.)

By the way, another issue that can cause mechanical problems (for the NEMA 14-50 receptacle) is plugging and unplugging the (CMC or MC) plug regularly/daily. Try to leave the (big) 14-50 plug in the receptacle semi-permanently. We are told (by experts) that receptacles are really intended to leave the plugs left in (as for a dryer, range, or other large appliance). If not, over time there can be gradual wear and tear that can lead to problems.

Keep us apprised of your findings.

 

[E90alex]

I would add this...

Over the years there have been reports (here on TMC and elsewhere) of issues using the NEMA 14-50 wall receptacles. As near as I can tell, most of the problems have been due to using cheap (~$15) wall outlets (yeah, I'm talking about you, Leviton) and/or not tightening down the connectors properly. The much more expensive, but also much more well made, Hubbell/Bryant receptacles tend not to experience those problems (e.g., arcing) as it is easier to torque the connection screws down properly with the beefy Allen/hex bolts provided. (These issues can arise even for people who used professional electricians and who paid the extra "Tesla tax.")

Now it may be that CMCs have had issues, I don't know. But the very first thing I would do is to turn off the power and check the installation of whatever NEMA 14-50 wall outlet you have. Check for obvious signs of arcing. If there are no problems with the wall receptacle, and assuming you have the proper gauge of house wire (e.g., #6) and everything else (proper 50a GFI circuit breaker) about your house circuit is OK, then the CMC may indeed have a problem. Another obvious diagnostic tool would be to try and charge using a different cable, like the MC with a NEMA 14-50 adapter-plug, and see if the problems arise with that. (Of course, that cable will automatically limit your amperage to 32, so maybe not a completely fair test?)

By the way, another issue that can cause mechanical problems (for the NEMA 14-50 receptacle) is plugging and unplugging the (CMC or MC) plug regularly/daily. Try to leave the (big) 14-50 plug in the receptacle semi-permanently. We are told (by experts) that receptacles are really intended to leave the plugs left in (as for a dryer, range, or other large appliance). If not, over time there can be gradual wear and tear that can lead to problems.

Keep us apprised of your findings.

I created a thread when this issue happened with the details. You can search for it. Long story short, it was not a problem with the outlet or wiring. The CMC failed.

 

[tps5352]

I created a thread when this issue happened with the details. You can search for it. Long story short, it was not a problem with the outlet or wiring. The CMC failed.

Ha! I am embarrased to find I even contributed to that (your) thread. (I am getting old.)

 

[tps5352]

I added info about the original Roadster mobile connectors (2009; 2 versions). If anyone has/had one, I'd appreciate more information to fill in blanks. Photos coming.

 

[tps5352]

Photos of 240v original Roadster Mobile Connector added to OP.

 

[PCTAZRichard]

FWIW- I've seen reports of owners picking up mobile connectors at service centers. So call or stop by one if you're close.

The 14-50 connector I had that crapped out is no longer sold and Tesla replaced it with a hardwired connector, seems that there was a bad batch of them as others here have said. I've also seen enough reports of cheap 14-50R (receptacles) that scares me. If you go this route get a good receptacle.

 

[zroger73]

Because of the extra ( <2kW )charging rate?
If that is not a must-have, for an extra $30 the gen2 UMC is a lot more versatile and not currently on backorder.

In my opinion, a 25% faster charging rate is significant.

For the past month, I've been charging "for free" (to me) at a few NEMA 14-50 receptacles around town that are for public EV charging.

It would be nice to shave 30 minutes off a three-hour wait by charging at 9.6 kW instead of 7.7 kW.

 

[zroger73]

Word of caution, my 40A CMC started overheating in less than a year and it was dialing back on amperage to like 27-28A at its lowest with plug temps in the 130°F range.

There seems to be some anecdotal reports of some Gen 1 UMC overheating as well, of which the CMC is based on. Not sure how common of an issue it is since the CMC is already very rare as it is. YMMV, but possibly not worth the trouble to seek one out over the seemingly more reliable Gen 2 UMC.

I have issues with the gen 2 Mobile Connector overheating after 30-90 minutes when charging on a 100°F day in direct sunlight. One or more of the following happens causing the charging current to decrease from 32A to 16A:

• Plug overheats
• Mobile Connector controller overheats
• Vehicle connector overheats

At one location, I've been moving a garbage can in front of the Mobile Connector to shield it from the sun while charging to keep it from overheating.

When the overheating occurs and the charging current decreases, charging all but stops because most of the power is being used by the A/C compressor to keep the cabin cool.

Thankfully, I don't have to charge like this. I can always charge at home in a climate-controlled garage - I've just been testing free-to-me public charging to see if it is possible and practical.

 

[zroger73]

Uh-oh. Is the coveted Corded Mobile Connector officially dead?