Plugging in an RV and Tesla at a campsite

[cantdecide]

We are considering travelling around the country with our RV (30 Amp) and a Tesla (either our 3 or our 2013 S).
We'd like to be able to go to a campsite and plug both in... get the power we need in the RV and charge the Tesla as well as we can.
I'm trying to figure out the best way to do this?

Campsites usually have 14-50, TT30 and 5-20 but sometimes don't have the 14-50.
They don't like you plugging into more than one outlet at once, and the people who run the place have no idea about electricity and are scared of it.

Option 1) Plug the RV into TT30 and the Tesla into 14-50.
This is obviously ideal but campsites don't like it as you are drawing more than 40 amps and they are afraid you will blow their circuit breakers.

Option 2) Plug in a 14-50 extension cable to the campsite (to keep the campsite happy) then...
A 14-50 splitter ($99 on amazon).
On one side a 14-50 to TT-30 adapter (or splitter) and a cable for the RV.
On the other side the 14-50 into the Tesla in the usual way.
I would tell the RV to use 30 Amps and I guess the Tesla to use 10 Amp (or 20 Amp if I'm only averaging 10 Amp on the RV) as the RV only uses one side of the 14-50.
Or I would tell the RV to only use 20 Amp (averaging actually 10) and tell the Tesla to use up to 30 Amps.
With this I can get up to 6kw on the Tesla I believe but I do need to manage it.
As a bonus if I use the splitter I have a spare 10 Amp 110 volt I can use for something else.

Option 3) Start with the 14-50 extension cable.
Then use a splitter to split into 2 TT-30s. (only $20 on amazon)
One TT-30 goes to the RV
The other I need the evseadapters (for my 3 and S). Plug into the Tesla. (unfortunately this is over $100 in adapters)
Now I get 30 Amps fine on the Tesla but only 110volts.
This solution is clean but the Tesla can't get more than 3kw.

Then for 30 Amp campgrounds
Option 30-1)
Plug the RV into the campground
Plug the Tesla into the outside 5-15 on the RV... only getting ~1.4 kW.
Trust the RV energy management to figure out the rest

Option 30-2)
Once we don't need the AC in the RV, then option 30-1 has leftover energy, but how to use it?
Do option 30-1 until the RV battery is full.
Then use the EVSE adapter to plug the tesla in and camp relying on the RV battery, giving the Tesla the full 30 Amps, 3kW.

Any opinions?
Options 2 and 30-2 seem to give the most power but require the most management.

I really wish I had the cybertruck... plug the RV into the 220 volt outlet on the truck, plug the truck into the campground... the RV takes what it wants and the cybertruck charges with the remainder.

 

[Zcd1]

Not directly answering your question, but remember that you can set the charge current maximum in the Model 3, if that would help. If you use Tesla's adapters, the charger automatically draws the maximum allowable for the adapter/circuit, whereas if you use an aftermarket adapter, the user must set the maximum charge current in the car's charging screen.

I'm planning to use campgrounds to charge my car during an upcoming road trip, since there are no Superchargers and not much even in the way of L2 charging where I'll be driving...

 

[KenC]

I'd do Option 2, 30/10 split. Less to think about, and how much driving in the Tesla are you going to be doing on a daily basis?

 

[Saghost]

I would do either 3 or 30-1.

In option 2, the RV only using one side of the 14-50 doesn’t help the car any, because the car if hooked line1 to line2, and so both loads add directly on line1, and if they exceed the limit combined on any line they will trip the breaker.

 

[Rocky_H]

This is obviously ideal but campsites don't like it as you are drawing more than 40 amps and they are afraid you will blow their circuit breakers.

The answer is: do whatever you want. They mount the breakers right there on the posts at the site inside the metal box for this very reason, so if you trip the breaker, flip it back and try a lower level.

 

[BrokerDon]

Option #0: Run your RV off it's batteries or the (usually provided) 110V 15A outlet... and plug your Tesla into the 14-50.

We have a 2011 Winnebago View RV with dual 232Ah 6V DC batteries that only needs 110V AC "shore" power via it's 110V 30A TT-30 plug if we need to run our RV's 15,000 BTU AC. Otherwise it only needs a few amps from a 110V 15A outlet to run our lights, HDTV, etc... and recharge our RV's batteries IF it was unplugged and didn't get any sun for its 327W SunPower solar panel (which recharges our dual 6V batteries in a couple of hours).

Also, IF we drove our RV to the campsite for a couple of hours it would AUTOMATICALLY recharge our RV batteries from our Mercedes Sprinter chassis alternator.

 

[wws]

If you bring your Gen 2 UMC from the Model 3, it limits max current to 32 amps with the 14-50. So using a 14-50 Y leaves 8 amps for the RV side with your 14-50->TT-30 adapter. If 8 amps isn't enough for the RV, you can always dial down the Tesla to something less than 32 amps.

For a "30 amp" only campground, are there two TT-30s? If so, plug the UMC into one of them using the evseadapters TT-30 adapter (TT-30 Adapter for Tesla Model S/X/3/Y Gen 2 – EVSE Adapters), and the RV into the other one.

I'd also bring a 5-20 adapter for the UMC - for the case where there is a single TT-30 and a single 5-20. This would allow using the TT-30 for the RV and 5-20 for the car - if you so desire.

 

[cantdecide]

Not directly answering your question, but remember that you can set the charge current maximum in the Model 3, if that would help. If you use Tesla's adapters, the charger automatically draws the maximum allowable for the adapter/circuit, whereas if you use an aftermarket adapter, the user must set the maximum charge current in the car's charging screen.

Yep, the generic power adapters don't limit current but the Tesla ones do. I believe the EVSE adapters also do.

The answer is: do whatever you want. They mount the breakers right there on the posts at the site inside the metal box for this very reason, so if you trip the breaker, flip it back and try a lower level.

I think their issue is not the breakers on the individual circuits, but a larger breaker that goes across a section of the campsite.
Essentially the section of the campsite will have wiring and circuit breakers assuming that each campsite will plug into one port only (the 14-50) and if people start using the 50 Amp and the 30 Amp then they are worried it might overload that larger breaker.

If you bring your Gen 2 UMC from the Model 3, it limits max current to 32 amps with the 14-50. So using a 14-50 Y leaves 8 amps for the RV side with your 14-50->TT-30 adapter. If 8 amps isn't enough for the RV, you can always dial down the Tesla to something less than 32 amps.

Right, the S can do more than the 32 Amps but the 3 is limited to 32.
Even so I believe the 40 Amp limit for the 14-50 is for usage of 2 hours or more.
Provided the RV peaks at no more than 20 (there is a setting for that) and on a continual basis uses no more than 8 I should be fine with the 40 Amp and 50 Amp rules?
Maybe I set the RV to 20 Amps and the Tesla to 30 Amps as I haven't seen the RV continuously use more than 10.

For a "30 amp" only campground, are there two TT-30s? If so, plug the UMC into one of them using the evseadapters TT-30 adapter (TT-30 Adapter for Tesla Model S/X/3/Y Gen 2 – EVSE Adapters), and the RV into the other one.

Those will typically have one TT-30 and one 5-20.

I'd also bring a 5-20 adapter for the UMC - for the case where there is a single TT-30 and a single 5-20. This would allow using the TT-30 for the RV and 5-20 for the car - if you so desire.

Yep, we have a 5-20 for each of our cars. Provided the RV park is ok with us using both then that would be optimal in that case.

 

[cantdecide]

Option #0: Run your RV off it's batteries or the (usually provided) 110V 15A outlet... and plug your Tesla into the 14-50.

We have a 2011 Winnebago View RV with dual 232Ah 6V DC batteries that only needs 110V AC "shore" power via it's 110V 30A TT-30 plug if we need to run our RV's 15,000 BTU AC. Otherwise it only needs a few amps from a 110V 15A outlet to run our lights, HDTV, etc... and recharge our RV's batteries IF it was unplugged and didn't get any sun for its 327W SunPower solar panel (which recharges our dual 6V batteries in a couple of hours).

Also, IF we drove our RV to the campsite for a couple of hours it would AUTOMATICALLY recharge our RV batteries from our Mercedes Sprinter chassis alternator.

Our RV has a ~4kW battery and ~180watts of solar, so is similar to yours.
Unfortunately I believe our converter is broken as the battery will only charge from the solar, not shore power or the alternator right now.
The issue for us has been the AC taking up continuous 10 Amps at 110 volts. When the AC is running the battery only lasts a couple of hours.
When we aren't using the AC then yes, if we arrive at the campground full (working alternator setup) then we can leave the power for the Tesla for a while.
It sounds like what you are doing is my option (30-2)

Was it easy to get the solar installed? We're considering adding to the factory default as listed above.
It looks like you have a nice setup there.

 

[DaveRZ]

I don't think you're going to find an IDEAL solution here. As you have undoubtedly noticed in your RV travels, not all campgrounds are created and maintained equally. I've had some hookup posts that I was genuinely afraid to plug into, much less run A/C in the RV while running the microwave. Now add in the charging of your car and you've got a lot to think about. However, some better and newer campgrounds probably have great wiring where you could run all 3 outlets on the post simultaneously.

I would recommend the following: Buy all the adapters you need to be able to plug the car and RV into each type of outlet (so you can be prepared for any campground's configuration). You can safely draw 9600W, 2880W, and 1920W continuous from a 14-50, TT30, and 5-20, respectively. Then just actively manage IF you need to. Some days you won't need to charge the car at all, other times you'll need a lot of charge and in a hurry. Swap plugs as needed to make it work. Under normal circumstances just leave your coach plugged into the 30 amp, and probably charge the car off the 20 amp. The post should have no problem handling that and you should get about 55-60 miles of charge each night PLUS however long you don't need the car during the day. If you need a faster charge and less in the RV, plug the RV into the 20, and the Tesla into the 50. Only charge as fast as you need to, many campground have electrical problems (which is why RV's now come with sophisticated power management).

Worst case you only need enough charge to get you to a supercharger.

I think extension cords and splitters are a bad idea. Maybe in a pinch, but not for business as usual. Too much can go wrong and you're introducing more connection points into a system that is likely overstressed to begin with. Plus if it rains all your connections get wet instead of being protected by the panel's lid.

good luck, and safe travels! (I miss my RV)

D

 

[wws]

...Those will typically have one TT-30 and one 5-20...

I've seen dual TT-30s in a pedestal as well as TT-30 + 5-20.

Evseadapters offers TT-30 adapters for both UMC generations. However if you have the 14-30 adapters for either/ both your UMCs, there is this TT-30->14-30 adapter on Amazon that might be handy. Seems to be correctly wired for EV charging, instead of for RV usage:

https://www.amazon.com/ONETAK-Charger-Compatible-Connector-Connecter/dp/B07XNPHXV2?th=1

 

[BrokerDon]

Our RV has a ~4kW battery and ~180watts of solar, so is similar to yours.
Unfortunately I believe our converter is broken as the battery will only charge from the solar, not shore power or the alternator right now.
The issue for us has been the AC taking up continuous 10 Amps at 110 volts. When the AC is running the battery only lasts a couple of hours.
When we aren't using the AC then yes, if we arrive at the campground full (working alternator setup) then we can leave the power for the Tesla for a while.
It sounds like what you are doing is my option (30-2)

Was it easy to get the solar installed? We're considering adding to the factory default as listed above.
It looks like you have a nice setup there.

Actually our 2011 Winnebago View has a 0.327kW (327W) solar panel... which because it is mounted FLAT on our roof typically produces 200W max = 0.2kW.

Your broken converter definitely should be replaced / fixed. No reason to pay for 120V AC "shore power" and not have it charge your batteries / run your 12V DC loads.

Running an AC off your 12V batteries is going to be limited. 10A x 110V = 1,200W. If your battery bank is 4Kw (4,000W) it's not surprise that it only lasts a couple of hours... especially since ACs routinely pull > 10A during startup unless they each have an expensive "soft start" installed. Running AC on 12V batteries is a "party trick"... but not sustainable. You need 120V AC "shore power" to run your ACs.

So Yes maybe option (30-2) makes sense IF your 120V AC -> 12V DC converter is broken... but converters are relatively CHEAP vs. buying more batteries and adding more solar.

Speaking of solar, our 327W solar is perfectly matched to our 232Ah batteries. Obviously your 4kW batteries need a LOT more solar. DO THE MATH... and you'll find out how much solar you'll need to recharge your 4kW battery bank... and a MUCH larger number if you're tring to run your 10A 120V AC's off of your solar. Doable but EXPEN$IVE !!! Off Grid Solar Powered RV Air Conditioning - Is it Possible? - Gone With The Wynns

 

[Zcd1]

...However if you have the 14-30 adapters for either/ both your UMCs, there is this TT-30->14-30 adapter on Amazon that might be handy. Seems to be correctly wired for EV charging, instead of for RV usage:

https://www.amazon.com/ONETAK-Charger-Compatible-Connector-Connecter/dp/B07XNPHXV2?th=1

Thanks for this - I’m going to get one before my trip!

 

[dabbler]

We camp often with both our model S plugged into the 12V 120vt circuit and the RV plugged into the 30 amp 14-50. Never been a problem. Other campers are very jealous of the opportunity. RV is geeting fitted for solar in a month.

 

[BrokerDon]

We camp often with both our model S plugged into the 12V 120vt circuit and the RV plugged into the 30 amp 14-50. Never been a problem. Other campers are very jealous of the opportunity. RV is geeting fitted for solar in a month.

Exactly what I stated above... but in a lot fewer words.

Option #0: Run your RV off it's batteries or the (usually provided) 110V 15A outlet... and plug your Tesla into the 14-50.

 

[F14Scott]

I'm not an RV guy, so forgive this idea if it's stupid...

Does your RV's electrical panel/bus have the capacity to add an outlet or two from which you could charge your car? Or could you add a sub panel?

I'm thinking if you already have the cabling to plug the RV into any 14-50 or TT30 outlet at the park, then if you could add two outlets (one a 240V/20A 6-20, and the other a 120V/15A 5‐15) on the side of your RV, you'd have the proper amperages all set with the Tesla adapters, depending which RV outlet you choose, based on the park connection you've made.

 

[cantdecide]

Does your RV's electrical panel/bus have the capacity to add an outlet or two from which you could charge your car? Or could you add a sub panel?

The RV does already have a 5-15 external but of course that charges slowly.
RV energy management is complex and I don't fully understand it as yet. There is an energy management device in there that detects how much energy is being used and if the total surpasses the available then it shuts off devices. I have no idea if that needs to be replaced to go for 50 Amps, and what it could manage on the output side.
Even though our RV is new, the instruction manuals are very incomplete and I know more about it than anyone at the dealership.

 

[F14Scott]

Yeah, the crux is the 240V part. Even at 11 or 15 MPH (15 or 20 Amp, 240V outlets, respectively), you're golden, overnight.

 

[outdoors]

The answer is: do whatever you want. They mount the breakers right there on the posts at the site inside the metal box for this very reason, so if you trip the breaker, flip it back and try a lower level.

I did that once in New Hampshire. Was pretty stupid of me. Blazing hot day. Airstream chugging the power for the AC 30amp. Then did the 50 amp outlet for the S same time. Worked a few times with the mobile connector at pretty high amps. Then I blew out half of the campground. Went for a drive as all the people were coming out of their RVs with strange looks on their faces. Who knew there was such a thing as a standby generator for RV's.

I dialed it way back and was just fine. Woke with a 90% charge.

 

[F14Scott]

Just as I would never go into my bathroom and plug two hair dryers into two outlets I knew were on the same circuit and trust the circuit breaker to trip and not catch the house on fire, I wouldn't trust campground wiring of unknown providence to shut off gracefully when presented with big, continuous loads.

I am reminded of one of Murphy's Laws of Technology, which, while a bit dated, is germaine:

"The $400 television tube will blow to protect the $0.10 fuse."