My Model 3 will be delivered on June 19. A week later my wife and I head to Europe for 10 days. So I've been pondering how I can do maintenance charges for both my Model S and new Model 3 while we're away. As I don't have a garage, my charging is done outside via a curbside charging station which I built myself.
Here's a link to a thread that describes those charging stations. Fortunately, when I made the carbon fiber version I held onto the larger more spacious original. That version has much more room inside and a door that provides easy access to the 14-50 female receptacle. Of course, there's only one receptacle. So I looked for some kind of Y adapter cord that would turn one 14-50 receptacle into two. I found this
Parkworld 692095 RV 50 Amp 1 to 2 Y Adatper 14-50p Male Plug to Two of 14-50 female receptacles on eBay. This will enable me to plug the Model S UMC into one receptacle and the Model 3 UMC into the other. So that I don't overload the circuit I'll schedule charging so that the two cars charge at different times and don't overlap.
Anyone see any potential problems with this plan?
Lots of thoughts inline with others:
10 days would likely be fine, but I personally would like my cars plugged in just not knowing what they might do and what if you got delayed in your return or something...
Your plan of a splitter would totally work, though as others point out, crank each down to say 16 or 20 amps. Yes, as folks have said it is possible for these settings to somehow get "reset" but in that case presumably the worst case (if wired properly) is that your breaker blows. In this case it is NO WORSE than leaving the cars completely unplugged. So short of causing an electrical fire (unlikely), it would only be better than not plugging them in at all. Even if for whatever fluke reason this happened four days into the trip, then at least it is better than not charging for the full ten days.
I also want to call out that if even one or both cars reset back to trying to draw full current, I wonder what the chances of them running at the same time are? The cars only charge when their battery drops 3% right? Neither car would take that long to regenerate that 3% periodically and so you could play roulette for a while of which car happens to charge when. And again, if they did blow the breaker then you are still better off than just not plugging them in at all.
Some kind of splitter that takes you to lower ampacity receptacles (with the proper Tesla adapters) would be the most bullet proof overall. Say a splitter from 14-50 down to 6-20 would be optimal (though you would need adapters for both your UMC units and the splitter which may not be commercially available). Really though, the splitter to two 5-15/5-20's would likely be the simplest solution. That would give each car the ability to charge at 12a 120v (1.44kW) to their hearts content and they would not ever be able to remotely impact each other. Actually, think that splitter also lets you connect 5-20's and so with the right UMC adapters you could do 16a at 120v. Unless it gets really cold and your battery needs to run a heater in order to charge, this should keep you fully topped up with even just the 5-15.
I should call out that the splitter linked to above for the 5-15/5-20's does not have circuit breakers or fuses in it so that makes it slightly sketch. If you had a short you would be relying on the 50a breaker to blow. The cord itself in theory even has the two pigtails rated for 30a (so overbuilt).
I think you would likely be fine with any of the solutions discussed here. ;-) If it was me, I probably would buy one of the splitters.
Btw, I actually have never used time of day settings for charging - do these also control what time of day recharging happens to top back off batteries due to ignition off draw? Or do they only apply for main battery charging and then re-topoffs just happen as needed?
Have a great trip! And please report back!
