Boy lots of advice here. My only advice, hire an electrician to do it if you have any questions at all. You just paid 100k+ for a vehicle, spend the $200 or whatever it is to have it done by a professional. Then you know it's right and won't cause a fire. Better safe than sorry...
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Electric Joe
Member
To extrapolate a little further here, using Cyclone's numbers, which he admits assume an estimated 500 watts of charging overhead, 16a@120v = 1420 watts of usable electricity (I just subtracted 500 watts) and 16a@240v = 3340 watts (again, buh-bye 500 watts). That means you'll have more than double the usable wattage by doubling the voltage. So yes, you really do cut charge time in half by simply doubling the voltage. It might be a 50% improvement on paper but because the overhead is such a big factor at these low wattages, adding just a little more wattage makes a big relative difference.
I think this is my best option. I assume the UMC will know that the 5-20 adapter on the end of it now has 2 hots instead of a hot and a neutral?
T
mspohr
Well-Known Member
The Tesla chargers don't use the neutral. You'll have 240v across the 5-20 plug but the Tesla is happy with that. It will draw 16 amps at 240v (3.8 kW)
davewill
Active Member
More like the UMC doesn't care about the difference. The adapter simply tells the UMC (and ultimately the car) that it is connected to a 20a circuit and should limit charging to 16a. The charger in the car is happy with a wide range of voltages and obeys the 16a limit..
Great news I got a really good price from an electrician so I am going to be able to get this garage outlet rewired as a NEMA 6-20 for nightly charging, and also a NEMA 14-50 up by my house (my garage is unfortunately about 150 ft from house) to replenish after a road trip. Will be interesting to compare efficiency of charging between the two.
Ordered the stuff for the adapter cable I'll just have him wire that up for me also.
T
Ordered the stuff for the adapter cable I'll just have him wire that up for me also.
T
Electric Joe
Member
There's something oddly satisfying about having several adapters and knowing that you can plug in just about anywhere. In reality though, I've found that it's extremely rare that I need to. With an 85 KWh battery, even with my 100+ miles of driving each day, I almost never have to charge away from home.
I agree with @davewill, this is a good option for you.
See the excellent Adapter Guide @Cosmacelf put together, page 15.....
mspohr
Well-Known Member
Yes, things have improved a lot just in the past two years since I took delivery.
My first trip in Feb 2015 was from Lake Tahoe to Las Vegas. The only Supercharger on this route was in Lone Pine. On the way down, we charged in Bishop at a trailer park while we had dinner at the bowling alley (best food in town), stayed overnight in Lone Pine then headed across Death Valley, just barely squeaking into Las Vegas. On the return, we stayed at Furnace Creek and charged at an RV spot, Lone Pine SC and made it to Garnerville where we charged at a public charger and dinner at a Mexican restaurant. We gained just barely enough charge to make it back over Spooner summit (in a snow storm), arriving home with all of 7 miles remaining. We drove very conservatively and kept the heat turned down (heated seats and steering wheel to the rescue).
Compare that to the situation today where there are Superchargers in Garnerville, Mammoth Lakes, Lone Pine, Beatty on the same route.
I've charged several times from motel air conditioner sockets (with permission) which give a decent 10 mph from the 6-20 240v. Last time was in West Yellowstone where I ran the charge cable from the AC over a second floor balcony to my car below but, of course, now there is a Supercharger in West Yellowstone.
Still good to have my collection of adapters since you never know where you will end up.
krazineurons
krazineurons
I had a standard 120v/15A slot and I was getting a paltry 2miles per hour. I followed the advice of awesome folks on this thread Charging from NEMA 6-20 using NEMA 5-20 Adapter
and now still use the 5-15 tesla adapter with the 6-20 5-20 pigtail in the 240v/20A slot and am getting 9miles per hour. I could upgrade to 5-20 and get perhaps around 12miles and hour but I am not considering that yet. So yes definitely go ahead and do upgrade, it's worth it.
and now still use the 5-15 tesla adapter with the 6-20 5-20 pigtail in the 240v/20A slot and am getting 9miles per hour. I could upgrade to 5-20 and get perhaps around 12miles and hour but I am not considering that yet. So yes definitely go ahead and do upgrade, it's worth it.
Built the 5-20p to 6-20r adapterr, worked out great! Was getting 3 miles/hr on 120v/15 amps, 4 miles on 120v/20amps, 8 miles on 240v/15 amps, and now 10 miles on 240v/20 amps with the adapter.
New buys should know about this as its a great option that none of the electricians recommended by Tesla even mentioned. $5000 to trench wire and go under some concrete to get to my detached garage and install a NEMA 14-50, $250 for this. I'll take it. I only drive 40 miles/day anyway.
Cyclone
Cyclonic Member ((.oO))
Did I miss these in the Op? Knowing such details would surely have changed my recommendation for getting a 14-50 installed. A 14-50 at my house going up one story and over across to the attached garage cost me $450. At the second house with the panel in the garage, $100. I guess the wire gauge for 14-50 couldn't be sustained in the existing conduit to use the old wire to pull through new wiring (plus the wiring cost). At $5k, I also would have planned to rework and use the existing wiring.
krazineurons
krazineurons
He can't be using the 5-15 adapter to pull 16A. The 5-15 and 6-15 adapters are capped at 12A max. You can only adjust down, not up.
I got the 5-20 UMC from Tesla and made an adapter, which was super easy anyone could do it. I can send you the links to the parts you can order from Amazon if you want.
krazineurons
krazineurons
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