Time for a long distance trip

Time for a long distance trip

I need to drive the 1600 miles from Seattle to Phoenix and have been trying to figure out how long it will take. The total time will be the driving time plus the charging time (plus sleeping time). Because I will be getting a 230 mile (60kw-hr) model, I chose an arbitrary 200 miles between stops. I assumed the use of a J1772 charger which is 220V and 70A (Usually only 80% of this current is available.) Thus, the charging rate will be 220*0.8*70 = 12.3kw. The power consumption rate of the car was tabulated according to the graph found at I calculated the travel time for every 10mph from 10-70mph.
Speed Time Whr/mi kw-hr Charge time Total time Avg Speed Time SEA-PHX
mph Hours used Hours Hours mph Hours
10 20.0 110 22 1.8 21.8 9.2 174.3
20 10.0 130 26 2.1 12.1 16.5 96.9
30 6.7 145 29 2.4 9.0 22.2 72.2
40 5.0 170 34 2.8 7.8 25.8 62.1
50 4.0 200 40 3.2 7.2 27.6 58.0
60 3.3 240 48 3.9 7.2 27.7 57.8
70 2.9 280 56 4.5 7.4 27.0 59.2

For example, if the car was driven for 200 miles at an unrealistic speed of 40 mph the travel time would be 200/40 = 5 hours.
To calculate the charging time, the power consumption/mile was multiplied by the distance traveled. At 40mph the power consumption is 170W-hr/mile (from the graph) so the total energy consumption is 200x170/1000 = 34kw-hr. The length of time required to replenish this amount of energy 34kw-hr/12.3kw = 2.8hr. If you use a different charger, this time will be different.
That means it will take 7.8 hours for a 200 mile segment if using a charger with the above specs and traveling at 40mph. The average speed of travel will be 200mi/7.8hr = 25.8mph. (This seems very slow but if you drive and ICE at 75mph for 8 hours and then stop for the night, your average speed will be only 25mph: 75*8/24.)
Doing these calculations for speeds from 10-70mph yields an unexpected result. On this long trip, it doesn’t look like it matters whether you go 55mph (for maximum range) or 70mph (keeping up with traffic). The difference in arrival time will less than 2 hours. However, after 200 miles at 70mph you will have used up 93% of your charge. I hope there is a charging station waiting.

cerjor | April 9, 2012

The table looked great when typed in but a lot of spaces were omitted. The total time from SEA-PHX is the last column of numbers starting with 174.3 and ending at 59.2.

Jason S | April 9, 2012

So I think you're saying that we can all drive pretty normally and be ok, as long as can find a charger in a convenient place.

I'd consider worst case charging scenarios like 10 amp circuits. How many miles per hour of charge at 10, 20, 30, etc. amps?

Supergreekster | April 10, 2012

I don't know if this is the perfect graph to use, ere is one under blogs specific to roadster, we should start there... Then range at 55MPH should be made 230. Then recalculate.

Kallisman | April 10, 2012

Maybe this will be helpful:
You can add the Tesla Model S, but I think the numbers are still preliminary.

jbunn | April 10, 2012


Most new construction common US wall outlets are 20 amp circuts. Charge time something like this...

20 amp (derated to 15 amp) at 120 VAC = 15 x 120 = 1800 Watts.
1800 Watts for one hour = 1.8 kWh

Full charge on a 80kWh pack (assuming all 80k) from the socket your buddy plugs his weed wacker into on the drive, 44 hours, not including charging losses and the power the car consumes for management (perhaps 15%).

When calculating, you'll need to know not only the amps, but the volts as well. 20 amp circuts are usualy 120 VAC, but a dryer circut might be 30 amps at 240 volts or 7.2 kWh, and a full charge can be had in 11 hours or so.

YAMMV, SYDFD! (Your actual mileage may vary, see your dealer for details)

stevenmaifert | April 10, 2012

@cerjor Way to go! That's the sort of planning we will all have to do to take our S cross country. I think your charging times are a bit optimistic though. Although the SAE J1772 standard allows for up to 80amp charging, your typical commercial Level II charger output is more in the 30amp range:, Will you be getting the twin charger option on your S? The single 10kW on-board charger will start to max out when the charge current reaches ~40amps.

Supergreekster | April 10, 2012

I think this should be how the nav does trip planning:

1) it will know "current charge level"
2) it will have to figure out "driver speed level"
For example, do you drive the speed limit, +1 MPH, etc. on average
3) this will then be converted to range
4) it will know where chargers are and what rate they are capable of
5) it can locate hotels (nav)

All driver puts in is destination, and perhaps starting time as well. Step one according to computer may be "charge at home for xxx minutes/hours"

Jason S | April 10, 2012

A long term draw from a normal wall socket should be derated further to avoid overheating the wall socket, imho. So that's why I choose 10 amps @ 120 VAC for the worst case.

So 1200 Watts to be safe. 54 hours for full charge of the 65Kwh pack used in this example. A dryer circuit would be much better, obviously, but good luck parking your car in the laundry room. ;-)

So you really can't just stay at a hotel and plug into a wall overnight. You'd need a higher power charger at your stopping points.

Supergreekster | April 10, 2012

You will need long cable to 220 dryer socket... Tis would be my plan to charge at friends house when visiting/driving through... But 220 not exactly easily accessible either... Move dryer... Etc.

Jason S | April 10, 2012

And that long cable will need to be very thick -- 14 gauge minimum to carry a 30 amp constant draw, maybe 12 gauge.

Supergreekster | April 10, 2012

Yeah. Thick.

Supergreekster | April 10, 2012


David M. | April 10, 2012

Don't count on finding very many 220V, 70A charging situations. The best you will be able to do will be 220V, 50A at RV parks. Otherwise, you should expect 220V, 30A (charging at a max of 24A).

Anyway, without dual chargers, the best the Model S can do is use the Tesla Superchargers (DC), otherwise, the best will be a 50A circuit (charging at 40A), if you can find one.

DanD | April 10, 2012

I'm planning my cross country trip from the factory to Trenton, NJ with stops in Dallas and Winston-Salem, NC.

I'm interested in sharing findings with others who are trying cross country trips.

I can already tell that Tesla not supporting the existing Fast DC chargers is a problem.

I'm at the point where I'm collected charger maps. But it may turn out that KOA campgrounds are the fall back approach. Drive for 200 miles, sit for 6 hours on a 50amp plug and drive another 200 miles and then stay overnight at an Elements Hotel (which has chargers).

I'd like to find B&Bs with chargers and to lobby Tesla to get cracking on the super-charger issue.

jbunn | April 10, 2012

No need to freak out about the cords though. Best way is to make up your own. You can eiether look up the ampacity in a book, or ask someone here. Bulk cable is sold at home supply stores, and the ends too.

Carrying capacity is determend by cord legth, conductor size, and the temperature rating of the insulation. Collectivley we refer to this as ampacity (or carrying power).

A thing to consider is length. A cable that is too long has a voltage drop. So right-size your cables. Perhaps you want a pair of 25's if most of your parking is within 15 feet of an outlet, but for special occasions you need a bit more. Use the shortest, highest ampacity cable first.

Look at the Tesla charger, and you'll see what I mean. Small gage but high ampacity.

We have a frunk, which looks like a great place to coil heavy cable!!

Sudre_ | April 10, 2012

30 amp draw (any voltage) for the amount of time needed is at least a 10 gauge, I would use a #8. There is a reason Tesla doesn't want us using extension cords.

Seattle to Phoenix (broken up by chargers)
Charge points from Recargo Android/Ipod App.

-Seattle to Ellensburg, WA (110 miles) There is a J-1772 ChargePoint Charger. There is a 2 hour charge limit.

-Ellensburg to Kennewick, WA (120 miles) There are a few J-1772 but the app says unknown. I have found that means private lot. There is also a Nissan dealer that claims public use.

You will have to find something in between.

-Kennewick to Just before Boise, ID. (250 miles) There is a 14-50, "Charger in the pasture next to the house. Call ahead for rates and parking."

You will have to find something in between.

-Boise to Clinton, UT. (350 miles) There is a J1772 at a Walgreens just before Salt Lake. No details in my app except open 8am-10pm. probably only 30 amp.

Clinton to Springville Walgreens, UT (80 miles) just south of Salt Lake.

Springville to Fillmore KOA, UT. (100 miles) 14-50.

You will need to find another charge spot.

Fillmore KOA to Flagstaff, AZ. (375 miles) Nissan Dealership J1772. App says, "Leaf customers preferred."
Another at Batteries Plus NEMA 14-50.

Flagstaff to Sedona Rouge Hotel & Spa.(40 miles).. sounds like a good spot to stay. NEMA 14-50

Sedona to Phoenix. (120 miles)

Good luck.....

andrewmfallon | April 10, 2012

I'm planning on getting a 220-240 converter to carry on long trips. Check out the manufacturer's web site:
This was discussed on the TMC forum and there are a number of posters who have used this. Basically it takes two 120 circuits which are out of phase and created 240 volts and cuts your charging time in half. I think it would be ideal for those times when nothing else is available.

Robert.Boston | April 11, 2012

For the SEA-PHX run, I would definitely use the I-5/US-101 corridor rather than Sudre's inland run. Charging is much more plentiful in California than in Nevada! It's a few miles longer, but far more EV-friendly.

David M. | April 13, 2012

johns258 - Thanks for the info on the quick220. That device could come in handy when you can find two 120V outlets on different circuits (in close proximity). It's great to be able to cut your charging time in half, when 220V is not available.

dborn | April 13, 2012

Wonder why the USA is on 110 at all. Rest of the world is on 220 at the ordinary outlet. Many places in Australia, (my own home included) is partially wired 3 phase (for the air conditioning and an in-house elevator). Can draw at least 440 v at 20 amp through that and possibly more with appropriately sized wiring and plug! For me, installing such a socket in my garage will be only a 15 yard cable run! A no-brainer if i find i have an issue with charging times!

Brian H | April 14, 2012

Why? History and bad luck. ;)

mlascano | April 14, 2012

dborn -the "rest of the world" is not all at 220V. All the Americas -North, Central and South (except for the most southern tip, Paraguay,Chile, Argentina, Uruguay)- are 110-220V standard.

Brian H | April 15, 2012

Like I said, history and bad luck. Sometimes it's better to be second!

BYT | April 15, 2012

@Brian H, "Sometimes it's better to be second!" He posted on a forum with early adopters... ;)

It is true to be sure, but there will never be a second if there isn't a "first!"

Brian H | April 15, 2012

Heh. But consider that there could be a parallel, here. Imagine in 2 or 3 yrs a new battery tech and standard come out, many times as powerful and much cheaper -- but incompatible with the TM design, even and especially on retro-fit. Oops!


BYT | April 15, 2012

It could happen, and I could get hit by a bus in 2 or 3 years without ever experiencing the thrill of driving an EV from Tesla Motors. Also, the Model S wouldn't be the Model S without the skateboard design for stability, low center of gravity and the handling bonuses we are hearing about in TM's tests. If the new technology can't take advantage of that, then it's not a Model S to begin with.

I hear you, it's hard to pull the trigger on new technology when it's always evolving! But, before you get to old to enjoy it, pull the trigger today. Time fly's by so fast, Carpe diem! Seize the day my friend... :)

BruceR | April 15, 2012

120V 60Hz is the USA standard. 240V is obviously the second voltage available in your house because it is twice the lower voltage. Voltage and frequency vary all over the world but luckily fall into two large buckets. 100 to 127V and 200 to 250V (EU is now 230V standard). Here is a link to how crazy it has evolved from Edisons 90VDC original proposal for the lighting industry:
Tesla won the argument and implemented 110VAC, the rest as they say is a Babel story.

DarrellH | April 17, 2012

BYT, you are right on. Who knows what will happen 2-3 years in the future? We're not waiting for a miracle to happen. We are living for today!

My wife will have her Model S in a few months and I've had the Roadster for almost 3 years. Could there be an amazing breakthrough in EVs coming? Sure. But in the meantime, we are driving the best cars ever and enjoying our lives now. Thank you Tesla Motors!