Charging an EV from a 30 amp RV outlet

[drmox]

Does anyone have some real world experience charging an EV with a 120v 30 amp outlet?
Most EV charging discussions I have read talk about level 1 and level 2, or 120v vs. 240v. Well, a 30 amp outlet like at a campground would seem to fall somewhere between level 1 and 2.
Would a 30 amp plug be any improvement over a standard household 3 prong 15a charge rate?

[dznf0g]

Originally Posted by drmox

Does anyone have some real world experience charging an EV with a 120v 30 amp outlet?
Most EV charging discussions I have read talk about level 1 and level 2, or 120v vs. 240v. Well, a 30 amp outlet like at a campground would seem to fall somewhere between level 1 and 2.
Would a 30 amp plug be any improvement over a standard household 3 prong 15a charge rate?

You can do it, but it is not between level 1 and level two. The car senses if it is 120V and will only drink at a max amperage. 12 amps @ 120V is a pretty universal max setting that the car will draw, so as not to allow the operator to overload a typical 15 amp circuit. So, even though you are hooking to a 30 amp outlet, the car will only draw 12amps max. Some (if not all) vehicles will default to an 8 amp draw, as it does not know if you are hooking to a 1930s era circuit or a 1990s+ circuit. It is up to the operator to bump it up to 12 amps.

[jcl]

With a 30A 240V outlet, yes. I have a case full of adaptors for our EV charge cable.

I haven’t purchased this one yet, but there are adaptors available. TT30 to the Tesla Gen 2 mobile charge kit. Automatically sets the charge level to 80%, so 24A. Double the charge rate of a 15A circuit running at 12A.

https://www.evseadapters.com/product...l-s-x-3-gen-2/

Not sure what is possible with other types of EVs.

This adaptor is for those who have a plug for the 50A receptacle, and has apparently been tested with the Leaf.

https://www.evseadapters.com/product...0r-ev-adapter/

[dznf0g]

Originally Posted by jcl

With a 30A 240V outlet, yes. I have a case full of adaptors for our EV charge cable.

I haven’t purchased this one yet, but there are adaptors available. TT30 to the Tesla Gen 2 mobile charge kit. Automatically sets the charge level to 80%, so 24A. Double the charge rate of a 15A circuit running at 12A.

https://www.evseadapters.com/product...l-s-x-3-gen-2/

Not sure what is possible with other types of EVs.

I wired a 30amp 240v circuit at home....but that isn't OP's question scenario.

I actually ran wire for a potential 50amp circuit, but installed 30amp breaker and outlet since my 2018 volt will only accept 12 Amps at 240v.

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[jcl]

Originally Posted by dznf0g

I wired a 30amp 240v circuit at home....but that isn't OP's question scenario.

I actually ran wire for a potential 50amp circuit, but installed 30amp breaker and outlet since my 2018 volt will only accept 12 Amps at 240v.

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The two adaptors listed are in response to his question, I just haven't used them myself. Both are specific to a TT30 receptacle.

edit: doesn't appear they would help if your EV is limited to 12 amps, as your Volt may be.

[Dennis C]

Charging speed depends on both voltage and amperage. Watts = Volts x Amps. If you’re limited 30 amps and 120 volts, then the maximum potential charge rate is 3.6kW. Battery charge rates vary based on state-of-charge, ambient temperature, onboard charge controllers, etc.

I’ve got a 240V, 50A circuit in my garage at home that’s dedicated to the electric car charger. My car has an onboard charge controller that limits the charge 40A, giving me a maximum charge rate of 9.6 kW, which is typically what I see when charging. The 2021+ versions of my car accept 50A and speeds up to 12 kW.

I think that it’s very possible that a 120V, 30A circuit will provide a slightly faster charge than a 120V, 20A circuit if the onboard charge controller allows it. However, I don’t think it will be a great deal faster with 30A. It won’t give you something that’s halfway between Level I and Level II chargers.

That’s just my theory based on simple math. Maybe it will be better than I think.

[dznf0g]

Originally Posted by jcl

The two adaptors listed are in response to his question, I just haven't used them myself. Both are specific to a TT30 receptacle.

edit: doesn't appear they would help if your EV is limited to 12 amps, as your Volt may be.

Ok, I see where OP says in between level one and two. I must say, I am very surprised tesla allows the car to be commanded to 24 amps at 120v. Since they can't control what circuit and adapter is being used, they are allowing no safety net for stupidity. What am I missing here?

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[jcl]

Originally Posted by dznf0g

Ok, I see where OP says in between level one and two. I must say, I am very surprised tesla allows the car to be commanded to 24 amps at 120v. Since they can't control what circuit and adapter is being used, they are allowing no safety net for stupidity. What am I missing here?

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The control is in the connector. They are smart connectors, and each plug type has a voltage and current associated with it, and a temperature sensor as well. The connector communicates with the charging cable. I can use any of the smart adaptors shown below with my charging cable.

I guess they figure out if you installed the correct receptacle for the associated circuit, you are good to go.

Tesla don't offer a TT30 adaptor for RV connections, but the aftermarket does, and as long as they use the same design approach I don't see the issue. Then again, I am not an electrician.

[dznf0g]

Originally Posted by jcl

The control is in the connector. They are smart connectors, and each plug type has a voltage and current associated with it, and a temperature sensor as well. The connector communicates with the charging cable. I can use any of the smart adaptors shown below with my charging cable.

I guess they figure out if you installed the correct receptacle for the associated circuit, you are good to go.

Tesla don't offer a TT30 adaptor for RV connections, but the aftermarket does, and as long as they use the same design approach I don't see the issue. Then again, I am not an electrician.

I wouldn't be too nervous about this at my home where I know the quality of the circuit, but we all know how consistently robust and correct campground power pedestal supply is.

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[jcl]

Originally Posted by dznf0g

I wouldn't be too nervous about this at my home where I know the quality of the circuit, but we all know how consistently robust and correct campground power pedestal supply is.

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So the risk is that someone would pull 24A from a 30A power pedestal? Wouldn’t there be more risk of overloading the circuit with a load other than an EV? And if the pedestal plug got hot, there is thermal monitoring in the EV plug.

[drmox]

https://m.youtube.com/watch?v=evE1IUiVOI0

So I found this. He talks about his adapter, and how to change the charge settings in the car.

[dznf0g]

Originally Posted by jcl

So the risk is that someone would pull 24A from a 30A power pedestal? Wouldn’t there be more risk of overloading the circuit with a load other than an EV? And if the pedestal plug got hot, there is thermal monitoring in the EV plug.

My concern is not so much the load at the plugs, but rather the feeder circuits. It appears to me that codes generally allow for one rv (50a or 30a) and a 15 or 20a duplex for outside appliances....not one rv on the 50a, one (effectively) rv on the 30a and outside appliances on the duplex.

I'd bet that's why I started seeing prohibitions in a couple of campgrounds' literature this winter in my travels.

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[jcl]

Originally Posted by drmox

So I found this. He talks about his adapter, and how to change the charge settings in the car.

That is the same supplier as I linked in post #3. It was the second option.

The first option in post #3 was for an adaptor that goes right into the Tesla box, and so you don't then need to change the maximum charge rate in the vehicle settings, it knows it automatically.

[drmox]

So....if a 15amp household plug gets you a trickle charge at a snails pace of 1.4 Kwh, and a 30 amp 120v connection with the correct provisions effectively double that to the tune of 3 Kwh, that is really still just trickle charging.
Even the low end of 240v level 2 chargers take a while to charge a near depleted battery. The only real way to effectively charge at home is with a high power level 2 charger. And once you consider needing two of those if we try to prematurely do away with internal combustion vehicles, we're all going to need to upgrade our entire electric service, fuse panel, wiring out to the garage, and the wiring in the garage.
I'm gonna go buy stock in my electric company, and go to a trade school to be an electrician.

[Dennis C]

The charger network and the electrical infrastructure definitely need a dramatic improvement as electric cars co to use to proliferate. We’ll get there, but there will be some struggles along the way.

I used to drive our BEV down to Denver International Airport and park at one of the charging stations in the garage. They’re mostly Level 1 chargers, but that’s perfect for charging while you’re gone for a couple of days. The last few times that I’ve been there, every charger has been occupied. It’s mostly Teslas at this point, but that’s beginning to change.

[jcl]

Originally Posted by drmox

So....if a 15amp household plug gets you a trickle charge at a snails pace of 1.4 Kwh, and a 30 amp 120v connection with the correct provisions effectively double that to the tune of 3 Kwh, that is really still just trickle charging.
Even the low end of 240v level 2 chargers take a while to charge a near depleted battery. The only real way to effectively charge at home is with a high power level 2 charger. And once you consider needing two of those if we try to prematurely do away with internal combustion vehicles, we're all going to need to upgrade our entire electric service, fuse panel, wiring out to the garage, and the wiring in the garage.
I'm gonna go buy stock in my electric company, and go to a trade school to be an electrician.

We have used 15A connections on trips when we overnight at a place without Level 2 charge connections. It works. It isn't fast, but we just leave the vehicle plugged in. We still find it much more convenient than our last (ICE) vehicle, since we have never had a midgrade fuel pump at home.

Our L2 charger is 32A (40 A circuit). 7kW, so fairly fast. It is a common error to assume that vehicles will need charging from near depleted. We can charge from 20% to 80% in 8 hours, but a much more common top up is a few hours. We wouldn't install two L2 chargers; our L2 charge point can reach two cars, but we could install a dual connection charge point on the same power connection if we wanted, so we could plug in two vehicles at once, and it would balance the load automatically.

We didn't need to upgrade our building service or panel. We needed distribution wiring in the garage.

We may need more electricians, but the real money appears to be in advising consumers who don't know how this will all best work for them.

[dznf0g]

Originally Posted by jcl

We have used 15A connections on trips when we overnight at a place without Level 2 charge connections. It works. It isn't fast, but we just leave the vehicle plugged in. We still find it much more convenient than our last (ICE) vehicle, since we have never had a midgrade fuel pump at home.

Our L2 charger is 32A (40 A circuit). 7kW, so fairly fast. It is a common error to assume that vehicles will need charging from near depleted. We can charge from 20% to 80% in 8 hours, but a much more common top up is a few hours. We wouldn't install two L2 chargers; our L2 charge point can reach two cars, but we could install a dual connection charge point on the same power connection if we wanted, so we could plug in two vehicles at once, and it would balance the load automatically.

We didn't need to upgrade our building service or panel. We needed distribution wiring in the garage.

We may need more electricians, but the real money appears to be in advising consumers who don't know how this will all best work for them.

I agree with this. Most of our lifestyles are such that the vehicle sits at home a lot. Commutes average less than 50 miles per day...etc. fully depleted batteries on a daily basis with today's battery capacities really isn't that often. I just have a Volt with a 14.1kW capacity, but it's pretty easy to forecast my next (non-TV) second car. It will be an EV. With my current Volt, if it is fully depleted, it is fully charged in a bit over 5 hours with a level 2 charger. I am on hourly pricing, so my charge starts around 11:30Pm and ends at 5AM. I've never paid a whole lot of attention, but I'd bet I'm charging a fully depleted battery 3 - 5 times a month.

I doubt that my lifestyle will require much of an upgrade to the house. Maybe just a 50 amp/240v circuit instead of the present 30 amp/240V. As stated earlier, I ran wire for a future 50 Amp provision, but I already had a 30 amp breaker on hand and didn't need 50amp for the Volt.

I did the same at my son's house. He has a 2013 Volt with 180k miles on it and is presently shopping EVs. I am sure I will be upgrading his breaker and outlet soon. They are commuters, but even their use doesn't justify the cost of major electrical upgrades.

[jcl]

We had assumed that our strata building would need a new transformer and service from the utility for our EV charge point project. We installed 144 separate L2 chargers on 40A circuits with 32A breakers. The service, and main transformers, were fine. We have 200A panels in each unit, but didn't use those. From a load study, even if all the chargers were running simultaneously, we had plenty of headroom. It was all the connected loads (steam showers, heated tile floors, etc) that never got used.

At the start, 10 of us wanted charge points. At the strata meeting, we got the vote through because of future proofing the building, not because there were that many EVs. We had the contractor wire connection points for all 144 strata unit owners. When we installed them, over 100 unit owners opted to buy the actual charge point in their parking stall. Lots of EVs coming in now.

[Dennis C]

We didn’t need any upgrades when the electrician installed the outlet for our ChargePoint charger. It took less than an hour.

I read an interesting article in Forbes a while ago about how people need to change their thinking when it comes to electric vehicle charging. Most people have a gasoline refueling mindset, meaning that you wait while your car is refueled and then you move on to your next task. The BEV mindset is different. You need to think about what you can do while your vehicle is charging instead of waiting for it. The most obvious thing is sleeping while your vehicle charges in your garage. But you can also shop, eat at a restaurant, watch a movie, etc.

I’d estimate that 98% of our charging is done at home. We typically charge when the battery level is somewhere between 20% and 30%.

[drmox]

I see how this all makes sense. How the traditional gas station as we know it may be primed for extinction, to be replaced by rows of charging docks at work, stores, restaurants, and apartment complexes.
And if that becomes the reality, your EV will never really have the opportunity to drop below 50-60% charge because it is always getting plugged in wherever you go. In that universe, perhaps the 120v 30 amp outlet I have installed next to my Airstream in the driveway might just be enough to support the charging needs of the EV my DW wants me to buy her.