[ogdobber]

If you have used the “travel charger” on 110v you know it’s nearly useless. 1-2 miles per hour of charge means that best case from 0-100% it’s going to take 150 hours to charge. It should be called the vacation charger, because it will trickle charge your battery (which is good for it) but takes forever. I did just that, went out of town for a couple weeks and left it on the 110v “vacation” charger and as you can see from the first pic, it went well, but nearly 5 days to go from 22-100%.
However, let’s say you actually go on vacation and get an airbnb that doesn’t have 220v and there are no chargers around. This is the solution. I got the idea when I was wiring up my nema 14-50 at home (turns out I’m not the only one to think of this as there are a bunch on videos on YouTube)
Anyways, do this at your own risk. And spare me the lectures of how it’s not safe. Two out of phase 20 amp breakers is plenty for a 32 amp charger.

 

[Bandit]

And how many homes have two 20amp, 120v outlets each on a different A or B side, 3 feet apart?

 

[ChasingCoral]

I won’t lecture the OP about the safety of this but I will warn the newbies out there. If you think this sounds potentially dangerous, you’re right. What the OP is doing falls under the “professional work only, do not try this at home” category.

 

[Voltz]

And how many homes have two 20amp, 120v outlets on two different phases, 3 feet apart?

That’s where heavy duty extension cords come in to play. Desperate people do desperate things. Hope to never get this desperate and use it with a 16 A/240 V charger if I do.

 

[Leaf to Lightning : )]

there are actually many ADAPTERS just like this in the RVing world, where camping with a 240v 50amp Motorhome or Fifthwheel, with more power needs than the typical and more common 30amp 120v outlet can provide. Yes, it's not necessarily common to find two 20amp 'household' outlets near enough to make this an easy option, but using a 20amp extension cord(s) is usually the solution.
Of course, identifying two household outlets on different sides of the breaker panel is also part of the equation. If they are not, the adapter will not work.

Many folks will laud the virtues of 'safety' when it comes to these out-of-the-ordinary adapters for unique situations, but the reality is that they work, and are not any more 'unsafe' than using any other outlet.

 

[THEsocalledfan]

Her is my dilemma whenever I finally get to order and take delivery before my pro charger arrives...

I don't have any 240V outlets in my garage, but I have an unused NEMA 14-50 in my utility room just in from my garage. I doubt the mobile charger is long enough.

Thoughts on the safety of this type of heavy duty extension cord?

Amazon.com

 

[ErichKeane]

I think there is a product I saw on Amazon at one point to do this, but it had a 'tester light' in it to make sure you had chosen two good outlets for it. I thought it was a decent idea, but without a tester-light of some sort, you end up having to have a multimeter to get it right.

The 120v charger should charge at ~1kw, so its good for ~2 miles/hr. So at worst it would take 131 hrs (on an ER lightning) to charge.

These chargers are WAY more useful on the more efficient EVs. My wife's Niro does ~4 mi/hr and has a 77 kwh battery, so it takes ~70 hrs for a charge. On those cars, it can be useful to get ~30-50 miles overnight, which for many is enough to cover their day of driving. In fact, before we got our EVSE charger installed, we did just that: it was livable, but it meant plugging in the car every night.

As far as while out on a vacation, depending on where you were/how much driving you were doing during the day/length of vacation, it would be possible to live on a 110v charger.

As far as the lightning... I suspect it would be MUCH less livable at ~15-25 mi/night.

 

[ErichKeane]

Her is my dilemma whenever I finally get to order and take delivery before my pro charger arrives...

I don't have any 240V outlets in my garage, but I have an unused NEMA 14-50 in my utility room just in from my garage. I doubt the mobile charger is long enough.

Thoughts on the safety of this type of heavy duty extension cord?

Amazon.com

Based on this: http://www.paigewire.com/pumpWireCalc.aspx

You should be fine. Given 240v/ 1 ph, 50a, you can do ~275 feet of wire (which, note INCLUDES that in your wall!) with 6 gauge copper.

 

[THEsocalledfan]

Based on this: http://www.paigewire.com/pumpWireCalc.aspx

You should be fine. Given 240v/ 1 ph, 50a, you can do ~275 feet of wire (which, note INCLUDES that in your wall!) with 6 gauge copper.

Good deal. This may also allow me to charge at my parents (ironically, similar deal where dryer plug is near garage) as when I'm there, I need a 100% charge before leaving.

 

[208]

• 
  

• And how many homes have two 20amp, 120v outlets on two different phases, 3 feet apart?

Welp... Just so we are not confusing people, residential AC in the US is single phase. All the outlets in your home are running the same phase, i.e. the sine waves match. What you need with the split 110 leads is seperate circuits.
Home electrical is actually pretty simple. In most states it is legal to do your own. It is straight forward, but the penalty can be severe if you break the rules. The rules are easy to find (wire sizing etc), and it takes the mystery out of a lot of this stuff. 😎

 

[ErichKeane]

• 
  

Welp... Just so we are not confusing people, residential AC in the US is single phase. All the outlets in your home are running the same phase, i.e. the sine waves match. What you need with the split 110 leads is seperate circuits.
Home electrical is actually pretty simple. In most states it is legal to do your own. It is straight forward, but the penalty can be severe if you break the rules. The rules are easy to find (wire sizing etc), and it takes the mystery out of a lot of this stuff. 😎

More specifically: You need 110 leads on separate circuits that are on separate sides of the box. And yes, Residential AC in the US is a strange split-phase power.

 

[Leaf to Lightning : )]

right, the adapter is looking for two incoming HOT LINES from both L1 and L2 of the main power panel, or sub panel, just like it would with a 'regular' 240v supply, which has a double-pole breaker that connects to the two separate breaker bars from the Two incoming utility lines.
The adapter is simply 'creating' a 240v supply from two separate 120v outlets, just like the double-pole breaker does within the breaker panel.

 

[ZSC100]

How do you expect to draw 30A long enough to charge from from a 20A breaker? This may work in a few rare cases, but most 20A breakers will trip within a minute of a 30A load. Unless you can tell the EV to charge at a slower rate. I have a Chevy Bolt with a level 2 charger at my house currently and have it plugged into a 30A, 240V circuit in my garage. The cord and romex gets warm to the touch after several minutes of charging. The charger show 32A when charging steady state and although I hate that you can't adjust the rate of charge from the vehicle it appears that you can't. I've wanted to do this exact thing on trips, but unless you can turn down the charge rate to 5kW or less it won't work.

 

[208]

How do you expect to draw 30A long enough to charge from from a 20A breaker? This may work in a few rare cases, but most 20A breakers will trip within a minute of a 30A load. Unless you can tell the EV to charge at a slower rate. I have a Chevy Bolt with a level 2 charger at my house currently and have it plugged into a 30A, 240V circuit in my garage. The cord and romex gets warm to the touch after several minutes of charging. The charger show 32A when charging steady state and although I hate that you can't adjust the rate of charge from the vehicle it appears that you can't. I've wanted to do this exact thing on trips, but unless you can turn down the charge rate to 5kW or less it won't work.

The OP is talking about pulling off spit circuits, two separate 20a breakers. [email protected][email protected]

These conversations are highlighting how far the legacy automakers are behind Tesla. When a Tesla is plugged into a circuit, the vehicle begins a test of the circuit to see what it can handle. Are other things running on the circuit you just plugged into? If so, the Tesla will back its draw down to keep from blowing the breaker. Breaker too small? Again, the Tesla will adjust and use what it can.

GM? Nope
Ford? Nope

The Tesla will then give you a lot of information about what it is drawing, and give you full control over reducing the draw, or even trying a higher draw.

GM? Nope
Ford? Nope

There are some work-arounds for these problems (and yes, they are problems), and I am happy to employ these work-around to own and drive a Lightning.

Still... I hope the legacy makers catch up...

 

[ZSC100]

The OP is talking about pulling off spit circuits, two separate 20a breakers. [email protected][email protected]

These conversations are highlighting how far the legacy automakers are behind Tesla. When a Tesla is plugged into a circuit, the vehicle begins a test of the circuit to see what it can handle. Are other things running on the circuit you just plugged into? If so, the Tesla will back its draw down to keep from blowing the breaker. Breaker too small? Again, the Tesla will adjust and use what it can.

GM? Nope
Ford? Nope

The Tesla will then give you a lot of information about what it is drawing, and give you full control over reducing the draw, or even trying a higher draw.

GM? Nope
Ford? Nope

There are some work-arounds for these problems (and yes, they are problems), and I am happy to employ these work-around to own and drive a Lightning.

Still... I hope the legacy makers catch up...

Sorry you are 100% wrong on this and so is the OP in his claiming this works, unless he is using a 5kW charger or less.

120*20 = 2400Watts ---> times 2 = 4800Watts,,,, this is half of 240*40 which is 9600Watts

Think about the OP's solution as two 20A breakers in the panel, just not necessarily next to each other with a bridge bar across them so they trip at the exact same time. This is actually the only reason this isn't a perfectly safe and code compliant solution, because one beaker will trip before the other leaving one side of the 240v circuit HOT after the other side trips. This will not work unless you have ability to limit the EV's charging wattage to 5kW. Some chargers and I assume some EV's will allow this. The cheap Level 2 charger I have does not allow it and my Bolt does not allow it either. I wouldn't necessarily call this "behind Tesla" but more of an issue of "standardization" versus "proprietary". Also, there is no way electrically that a Tesla's charger can do what you are claiming it can do. There is no way you can "test a circuit to see what it can handle". You could do some basic things like observe voltage drop due to a load, but that is not a true and all telling test of the circuit. I suspect if this was ever advertised as such it was a BS marketing gimmick. I'm sure our lightnings will have the ability to set the max charging rate from the truck's UI, as more and more chargers are being installed this is a feature that every EV should have.

 

[208]

Sorry you are 100% wrong on this and so is the OP in his claiming this works, unless he is using a 5kW charger or less.

120*20 = 2400Watts ---> times 2 = 4800Watts,,,, this is half of 240*40 which is 9600Watts

Think about the OP's solution as two 20A breakers in the panel, just not necessarily next to each other with a bridge bar across them so they trip at the exact same time. This is actually the only reason this isn't a perfectly safe and code compliant solution, because one beaker will trip before the other leaving one side of the 240v circuit HOT after the other side trips. This will not work unless you have ability to limit the EV's charging wattage to 5kW. Some chargers and I assume some EV's will allow this. The cheap Level 2 charger I have does not allow it and my Bolt does not allow it either. I wouldn't necessarily call this "behind Tesla" but more of an issue of "standardization" versus "proprietary". Also, there is no way electrically that a Tesla's charger can do what you are claiming it can do. There is no way you can "test a circuit to see what it can handle". You could do some basic things like observe voltage drop due to a load, but that is not a true and all telling test of the circuit. I suspect if this was ever advertised as such it was a BS marketing gimmick. I'm sure our lightnings will have the ability to set the max charging rate from the truck's UI, as more and more chargers are being installed this is a feature that every EV should have.

Yup... 240 @ 20 amps, you are right... I looked at that too quick lol.

What the Tesla does is to slowly ramp up its draw from two amps to whatever the desired maximum is while watching for voltage drop. When it sees a drop beyond what tolerance should be, it instantly backs off, so as not to blow a breaker or create a hazard. It is a simple, and extremely effective system that I have watched in action at numerous ify outlets from Friends old wiring, to overloaded RV parks.

It works. 😎

 

[ZSC100]

That is a very clever method by Tesla and I imagine there ARE situations like old house wiring and/or very long breaker-to-outlet runs where it can totally work to in a way self limit itself. I'm not against Tesla and that is a very cool feature, but as an electrical engineer I wouldn't recommend this feature to anyone else. On a properly wired system voltage does not drop as a breaker is overloaded, the breaker simply trips. It's likely that this feature would just cause misunderstanding and frustration if a user expected it to solve the problem for them. EV owners need the ability to easily command their charge rate from the vehicle's UI. I imagine Tesla offers this as well and our Lightnings better or I'm going to throw a shit fit with Ford.

 

[208]

That is a very clever method by Tesla and I imagine there ARE situations like old house wiring and/or very long breaker-to-outlet runs where it can totally work to in a way self limit itself. I'm not against Tesla and that is a very cool feature, but as an electrical engineer I wouldn't recommend this feature to anyone else. On a properly wired system voltage does not drop as a breaker is overloaded, the breaker simply trips. It's likely that this feature would just cause misunderstanding and frustration if a user expected it to solve the problem for them. EV owners need the ability to easily command their charge rate from the vehicle's UI. I imagine Tesla offers this as well and our Lightnings better or I'm going to throw a shit fit with Ford.

Tesla does, GM & Ford EVs do not. And in my experience, that is not good, and needs to be added.

 

[Leaf to Lightning : )]

as for using a 'Y' adapter to draw from two different 20amp circuits - if one of the breakers trip, the EVSE will stop ...there is no safety issue.

 

[2023 lighting]

I like the creative thinking. 👌 I'm not so sure I'd plug my $80,000 into the contraption. And I know a good deal about home electrical having upgraded my 200 amp service drop, automatic transfer switch, main panel, most all new wiring in my house with permits and inspections.

What this really illustrates is the need for #1 the nationwide charging network. #2 building codes to require hard wiring for high amperage ev charging in new and rennovated structures.