I am down in Pagosa, my Model S is in Boulder after some fun track time before shoeing it with its winter tires. Now its time to get the Model S here to its permanent home. Because of schedules, it is working out best for my friend drive my Model S down here today and fly back with me tomorrow. He is a flight instructor that I trust with my airplane (worth more that the Sig Model S), and pretty good with vehicles in general, but not up to speed on electric road tripping. This is not an easy drive, its 295 miles, 3,000 ft net up hill, goes over 4 passes, and usually has head winds. The charge recommendations that I gave him were conservative to avoid any chance of range anxiety. I sent him a detailed e-mail that he recommended that I publish. Here are those instructions for others to share and comment.
Well-written email with very clear instructions. The only thing I'd change is on #6 .. "Don't drive more than the speed limit, UNLESS you 1) are on the last leg of your trip, and 2) have more than enough miles to get to your destination. Drop your speed if your estimated miles is close to actual miles you have left to drive. " Because, of course, it doesn't matter if it takes 1 hour or 6 hours to recharge when your last stop is for the night.
Also, from what I've heard from other owners, the 110v plug only gets around 2.5 miles of range per hour of charge.
Google "rv park 50 amp near..." any town on your route. That eliminates calling for 50 amp services. Also, most Google sites have RV web sites linked, and you can see hours, seasons open, etc. Plus phone numbers. It is so cool that one can do this while on the trip, not having to look for a wifi.
I thought I had read on one of the Roadster threads that extension cords are inadvisable or don't work for charging? Maybe different for Model S and/or because it's heavy-duty?
Good point on #6. I agree! When I am in my last leg, and relatively consistant conditions to the end (hard to find in CO mountains), I use the rule that battery rated miles need to be at least 20% more than the distance to go with a minimum of 10 miles reserve. If you have more in the battery, feel free to speed up, etc. If you have less, slow down and drive more conservatively. I always call and get confirmation on RV parks that are a little out of the way, or that I am counting on. Sometimes they don't update their web page, sometimes all of the 50-amp outlets are taken or reserved, one wanted $75 for a couple of hours, and I had one that just hung up on me when I said "electric car." That being said, I have found most RV Parks very friendly and accommodating. Until we get more 80-Amp J1772's in the wild (forget Superchargers for a long time), the RV Parks are the way to live off the land. It is very cool to be able to this enroute. My plan is to contact the Salida Chamber of Commerce to see what I can do to get an 80 Amp J1772 somewhere in their old town area. Its a perfect stop for an EV driving from the Front Range of Colorado to SW Colorado, has many nice shops and restaurants, and has a nice waterfront area along the headwaters of the Arkansas River, complete with Kayak course. I have a vested interest in this route and am willing to put in some capital to make it happen. I hope to find at least one receptive business owner.
As @TomSax recommended to me, the AllStays RV Park finder app for iOS is a fantastic tool for road-tripping in back-country areas. It lets you filter for 50A hookup-equipped sites, and the directions, descriptions, and reviews are generally current and accurate.
I tried a 50ft 14 gauge (relatively heavy duty) 120V extension cord and the car wouldn't draw more than 6A or so. Practically useless. Maybe would get better results with even more heavy duty cord, but I doubt it.
I would go w/ a 10/3 cord. 100ft will run you ~$130 but should work. I will be trying this out over Christmas as we are going to visit some friends and will have to run a cord to charge so will report back here.
Just did a quick test with a 100' 10/3 extension cord we have, charging display indicated it was able to draw 12 amps on that line.
I have successfully charged my Roadster at 15 amps with two 12/3 cords for a total of 65'. As i used a 25' and 40 ft cords. But i agree you need to stay away from cheap cords.
yeah 14/3 is definitely too small. I've done 12/3 75' (two cords). I may invest it a 100' 10/3 20A cord if Tesla ever produces a NEMA5-20 adapter (and make a 5-15 to 5-20 adapter if the plug is only 15 amps).
Well, the thought was as an emergency cord. Also for my trip, we're visiting friends at a time-share condo complex and 120V is all that's available and not near the parking lot. The good news is that we don't need much charge to get back home so 120V overnight will be plenty for us.
There is no reason for the third conductor (the neutral), just the two hots and the ground. The Tesla Roadster and Model S don't connect to the neutral. I've actually sawed the neutral off by 14-50 plugs so they can also go into 14-30 sockets (be sure to set the current down in the car!). MOST IMPORTANTLY -- if you run 12/3 or even 10/3 cord at high currents, it will get warm. That's ok -- just be sure that you don't leave it rolled up on a spool where it can't air-cool. If you have a long length of cord, uncoil it ALL, not just the amount you need. So here is an interesting question -- what is the optimal speed to drive the car at on long trips? The idea is to minimize the door-to-door time. Obviously if you drive faster, you can spend more time on the charger, so there must be some tradeoff. If the trip ends after the final recharge cycle at your destination (which isn't normally what most people would consider the end of the trip), and chargers are available anywhere you want (you don't need to worry about stretching a long leg between two chargers), then I believe the optimal speed is the one where the power use during the drive is equal to the power provided by the next charger. This is interesting, because the faster the charger, the faster you should drive! If you know the kWh of your next charger, set the cruise control on level group until the power meter is showing the power provided by the charger. An 80A charger is probably well over the posted speed limit! Ken