The two-Tesla charging cable conundrum

[wwu123]

OK, with my Model 3 on order, I still haven't seen a discussion on this topic so will post it. I realize this is not unique to the Model 3, but can come up with any two Tesla's or EV's for that matter, but is certainly going to come up more with widespread Model 3 sales... the question is, have others found the 20' length of the included mobile connecter (charging cable) to be just a wee bit too short to allow convenient placement of the NEMA outlet for charging two Tesla's, or EV's?

Many of us who have a Model S or X quickly realize that you don't need to buy a dedicated wall charger, Tesla or otherwise, as you can use the included mobile connector (UMC) with just a NEMA 14-50 or 14-30 outlet - thereby saving at least $500 plus additional electrician costs, compared to getting a plain NEMA outlet installed. I would hazard to guess that the majority of Model S owners actually charge only with the UMC at home.

It also becomes fairly obvious at home that there are only two good places to put an outlet or charger, either on the left wall, or on the front wall of the garage. On the left wall, it's ideal to park one Tesla on the left so the charging cable does not cross over the other car. With two Tesla's, the cable will cross over one car to reach the other - it's inevitable, and can pose some risk if drivers do not look for the cable before leaving the garage.

Therefore the front wall becomes ideal. But the Tesla's are 15-16' long, and presuming you don't touch your wall with your bumper, you need about 14-15' just from the wall straight back to the charge port. That leaves a precious 5' or so of cable length for lateral positioning from the wall outlet to the charge port. Given that two cars charge ports need to be laterally about 7-8' apart, is it even possible to use one wall-mount mobile connector to reach both cars - and if so, is the possible span of mounting locations for the outlet nearly practically prohibitive?

In this case the extra 4' of the Tesla Wall Connector makes a big difference, and if that was their designed upsell, it's actually quite clever. So instead of asking why Tesla didn't make the UMC 25' instead of 20', what are folks doing to address the two Tesla charging cable conundrum?
-using left or right mounting cable mounting, which requires additional diligence (note it's impossible with one Tesla to drive with the UMC attached, the car will warn you, but with a 2nd Tesla it will not tell you whether you're about to back into the cable plugged into the OTHER car)
-using separate NEMA outlets and charging cables for each parking bay
-springing for the Tesla Wall Connector for the added 4' length
-getting a long or short cable extension, which has its own issues - additional resisitve losses, losing the idealness of the 90 deg turn at the plug in the UMC, etc
-any other creative options?

 

[Lloyd]

Self explanatory

 

[boilerbots]

Well I am an EE and thinking about this a lot. I have an S, received my 3 a few weeks ago and because I thought the 3 would take forever to ship had recently purchased a Pacifica hybrid that also has a 35A charger with J1772 port.

What I want is load sharing like the Tesla wall chargers can provide but think it should be done via software through the internet. That would enable any and all chargers to be used, including the mobile charger.

In my garage I had two outlets installed on the left wall, both for welders and other garage stuff. I am now using both for car charging and have a short extension cord for both that leads to various chargers. I went to Home Depot and got 8awg SOOW cable for the extension of a 30A circuit and saw 6awg there that should work for a 50A circuit. Also get a surface mount outlet and it works fine with the right angle Tesla plugs.

For the 8awg extension I have monitored the cable temperature, plugs and outlets after extended 40A charging it is barely warm, where the gen 1 Tesla cable is much warmer.

Also remember that the gen 2 mobile is limited to 35A.

My current plan is that I run an extension from the left wall around the front to the center next to the second spot drivers side. I have a temporary stand that I hang the cord on (ok, it is a trash can).

 

[gregincal]

View attachment 276450

Self explanatory

I'll also point out that even if you had only one charger, the one in the middle would reach both cars. I'm confused from the OP why if they are mounting on a wall they are mounting on the wall furthest from the charge ports instead of the one nearest the charge ports, so instead of going along the entire length of a vehicle or over a vehicle it just needs to go behind one car to reach the other.

 

[Derek Kessler]

Can only have an outlet at the back of the garage? Then back the cars in; the 20 feet of cable will be more than enough then.

 

[suwaneedad]

I own a LEAF, which will continue to require near-daily charging, and soon will add M3, which will require 1-2x/wk charging typically. So I don't intend to increase my existing J1772 infrastructure at all. I'll just use the left-hand bay for whatever vehicle happens to need electrons at the moment. At least, this is my plan. If that becomes a hassle in reality, I'll be doubling back to this thread for solutions. Easiest would be for me to have an electrician move the existing setup to the center of the rear wall of the garage, enabling me to reach either car's port easily. It's a Siemens contraption from 2011, and it hums sometimes so my preference is for it to be mounted to an exterior wall (as it is currently) rather than on an interior wall (which the rear wall is).

 

[roblab]

I put 220 v 50 amp outlets near each bay, way back before I had my Tesla, now Teslas. You remember the old saw, "plan ahead". I plug both cars in at the same time, they charge overnight at 32a on my hundred amp circuit breaker box, and we're full every morning. Since we live 30 miles from town, sometimes we just take the car that's got the most charge.

 

[Chickenlittle]

I do not want to claim credit for this but did see a picture of charger mounted on garage ceiling with cord hanging down

 

[Az_Rael]

View attachment 276450

Self explanatory

+1 except with a messier garage. The extra cost is well worth the reduction in hassle.

 

[hacer]

My wife is about to get her model 3, then we will have two Teslas. I've got a single HPWC on the right side of the garage near the door. It has the long cable so it could reach a car on the other side. I think it will be rare to need to charge both cars on any given night. So my plan is to do charge as-needed. I don't really want to have the cord go behind one car to the other so it would mean alternating parking spaces.

 

[brkaus]

I don’t see a reason to not run the cord behind the other car.

Sure, you have to be aware and you have to unplug.

But the charging car will be charged overnight, so its not like it has to be plugged back in.


Personally, I prefer to back in the garage. Easier to see the sides of the car in the rear view mirrors.

 

[gocken2]

Here is my plan, Model S on left side of garage parked nose in, Model 3 on the right side backed in with 14-50 outlets on both right and left walls. Each car can charge using it's own outlet and they can charge at the same time. There are no cords going behind (or in front) of either car this way and the mobile connector will be hanging right by each charge port ready to plug in.

 

[wwu123]

Can only have an outlet at the back of the garage? Then back the cars in; the 20 feet of cable will be more than enough then.

I don’t see a reason to not run the cord behind the other car.

Sure, you have to be aware and you have to unplug.

But the charging car will be charged overnight, so its not like it has to be plugged back in.


Personally, I prefer to back in the garage. Easier to see the sides of the car in the rear view mirrors.

My situation may be more particular than most, but from my street to the garage is a full 180 deg turn, and particularly going into the garage, one has to make a progressively sharp graduated turn to avoid hitting a retaining wall on the left side. Backing into that is not an option; making the graduated turn backing out is tricky even.

Again, may be specific to me, but my the license plate dents in the front wall, as well as scrapes on the front corners of each car against the garage opening, are indicative of my wife's haste in coming and going. I fear that humans in general are not condiitioned to check for low obstacles like a dangling cord behind the car before rushing out the door, and it is basically blind to the rearview mirrors.

Also my garage is fairly narrow, so the way the UMC juts out puts it mere inches from the next car. Therefore the cord is likely to still be at an angle rather than flat on the ground when passing across the left car's bumper or wheel. The image going through my head is my wife hastily pulling the left unplugged car out, the thick cable snagged around the hatch, bumper or wheel wheel. The plug end of the UMC flies out of the wall, denting the quarter panel or cracking the glass on her car. The connector ends tears the charge port clean out of the right car, along with the taillight assembly and possibly damaging the quarter panel on that car as well. I could even imagine myself at least once in 10-years possibly forgetting myself and doing it, and once would be more than enough...

Perhaps I have an overactive imagination....

 

[brkaus]

I think you should consider the ceiling option. You will have a second EVSE to take when traveling. You have a double door or two single garage doors?

I’ll put in a photo tomorrow of how I have to park. It’s quite fun.

 

[miimura]

Whatever solution you choose, I would avoid having a cord crossing behind a car that is not plugged into that cord. It's okay to have the cord go behind the car that is plugged in because it can't move until it's unplugged.

My current setup has a 50 amp 240V socket on each side wall. For a Tesla, the left parking space is ideal because the charge port is close to that plug. However, for the right spot, you have to run the cable to the back of the car, around the trunk, then plug it in. I think the Mobile Connector cable is long enough for that. It's not a problem at the moment because the car in that spot is currently an e-Golf which has the charge port on the passenger side. It's being charged with a Jesla, a Gen1 Tesla Mobile Connector with the handle changed to J1772. The e-Golf will be replaced by a Model 3.

For the poster upthread that wants to load-share between a Tesla and non-Tesla vehicle, I would go with a J-Wall-40 from Quick Charge Power. It is a Gen2 Tesla Wall Connector modified to J1772. It is expensive, so it really only really makes sense if your panel doesn't have the capacity to charge two cars simultaneously.

 

[patrick40363]

I have a 40amp J1772 mounted on the front wall between our 2 cars. When the model 3 arrives it will use the charger along with my current model S . I made sure when I bought the unit it had a 25 ft cord just in case.

 

[BerTX]

I would put the outlet on the wall and run a NEMA 14-50 extension cord up to the ceiling across to the center between the two cars, and hanging down far enough to be able to unplug the MC if necessary. This puts the MC between the two cars, and as stated above, the car that the MC cable has to run behind when charging would not be able to move if plugged in, and otherwise the cable would not be behind it.

Not ideal, but it would work.

 

[brkaus]

For the poster upthread that wants to load-share between a Tesla and non-Tesla vehicle, I would go with a J-Wall-40 from Quick Charge Power. It is a Gen2 Tesla Wall Connector modified to J1772. It is expensive, so it really only really makes sense if your panel doesn't have the capacity to charge two cars simultaneously.

Just to be sure : The j-Wall-40 when used with another HPWC requires that they be set to 40A. It says so on the page, but I totally missed it and someone here clarified for me.

 

[miimura]

Just to be sure : The j-Wall-40 when used with another HPWC requires that they be set to 40A. It says so on the page, but I totally missed it and someone here clarified for me.

That is correct. Only the master actually sets the current and the slave must be able to use that current level. So, by using a J-Wall-40 you're bringing down the least-common-denominator to 50A circuit, 40A charging, even if you have a 80 amp capable Tesla Wall Connector paired with it. If you need more than 40A charging or have a circuit larger than 50A available, go for the regular J-Wall since it maintains the full capability of the Tesla Wall Connector, albeit with a J1772 connector.

 

[Big Earl]

I do not want to claim credit for this but did see a picture of charger mounted on garage ceiling with cord hanging down

That’s similar to what we’re doing in our carport right now. We have two JuiceBoxes mounted to the carport ceiling with the cables running down the support post. Both J1772 handles are mounted to the post and can easily reach four parking spaces. This keeps the infrastructure up and out of the way, out of the weather, UV damage from the sun, and inadvertent bumps and bruises from moving things around. When we get more EVs, we will either add a third EVSE or we’ll just figure out how to share the two EVSEs between cars.