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635 Mile Texas Road Trip down I-45 Corridor

Discussion in 'Texas' started by andystj, Feb 18, 2013.

  1. andystj

    andystj S: P957 X: P337

    Joined:
    May 14, 2012
    Messages:
    80
    Location:
    North Texas
    Just returned home from a two-day roadtrip from north of Dallas to Galveston and back. 314 miles down Sunday and 320 back today. I may post more details tomorrow or the next day, but I do want to post a couple of quick notes this evening.

    First, this is my second longish road-trip (the other being down I-35 to New Braunfels), and it is perfectly clear that John Broder is either: a) disingenuous, 2) an idiot or iii) all of the above. This car gives extremely good feedback as to your range, and it is very easy to adjust on the fly to minimize trip-time while leaving a safe margin.

    Second, the Supercharging network will be WELCOME in Texas. While Downtown Dallas to Austin is doable at a reasonable rate of speed, there is not much room to add to either side of that trip. Downtown Dallas to North Houston is only doable at a rate of speed that is not very comfortable on I-45 at least when range is affected by a 20mph headwind.

    Knowing I would have to stop and charge on my trip, I found a very nice accommodating and convenient RV Park just South of Madisonville. I happily recommend Home on the Range RV Park as a place to stop and pick up a few electrons. They are easy to find just south of Buc ees (exit 142 heading South or 136 heading North). They have a great little restaurant at the park that serves mostly fried seafood and burgers. The 50 amp hookups had solid 240V output, so I was able to get a nice 10KW of power. They simply charged me for the power I used (with almost no mark-up) though I did patronize their restaurant.

    My charging experience at Home on the Range was MUCH better than my other charging experiences during the trip. My final destination was Galveston, and I plugged in at an RV Park off of Offats Bayou before heading over to visit family and get some sleep. Upon leaving, it looked great with 40Amps at 220V and an expectation that I would be full in the morning. Alas, checking my android App an hour later, I found charging had stopped. I headed back to the park to find the breaker tripped. I moved to another spot closer to the office and started up again. After waiting for 15 minutes I headed out. An hour later, just before retiring to sleep I checked again and found charging again had stopped. A final trip out and a third open slip . . . This time I dialed the charger down to 32 Amps. It was late, and so I got back and went to sleep to find that the breaker had again tripped. I don't know if their wires were undersized or their runs were too long, but they were not ready for a 32-40amp draw. Sadly I was left with 120 rated miles when I got up this morning and 320 miles to travel. Alas.

    Realizing that I would need to get charging I headed up to my next stop which was the Houston Heights. Charging there was easy, but not efficient. My first stop was a Chargepoint station at a Whole foods. No problem, but at 30Amps times 185Volts I was only getting 5.5KW of power. After grabbing a few electrons there while downing some coffee and a pastry, I headed up the road to a Blink station at the Heights branch of the Houston Public Library. This was within walking distance of my destination, so I was happy for the convenient location. Again, no problem, but the voltage was right around 205V. The 30Amp draw at 205V was still just 6KW, and I had 265 miles left to travel. It was nice to get the electrons while I was there for a few hours. I find the low voltage interesting, and I wonder if it is because of the fairly old infrastructure in that part of Houston.

    Leaving Houston with 130 miles of rated range, I enjoyed a nice tail wind for the first 40 miles of my return trip before running into a gully-washer and of a cold front. All the efficiency I picked up from the wind push was lost in the rain storm, but the car handled great. I was happy to get back to Madisonville and find that sweet 40Amp x 240V charging station. I enjoyed a nice lunch and some quiet time before heading home after picking up some needed KWh.

    :)

    Andy
     
  2. drees

    drees Active Member

    Joined:
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    Messages:
    1,121
    Location:
    San Diego
    Commercial businesses often have 208V 3-phase power, so your typical J1772 charger will be supplied with 208V instead of 240V, so 200-208V is pretty normal on a commercial charger. Anything lower than that, though is suffering from severe voltage drop. 185V, ouch! Something is getting ready to burn up there!
     
  3. andystj

    andystj S: P957 X: P337

    Joined:
    May 14, 2012
    Messages:
    80
    Location:
    North Texas
    The 3-phase power explanation is very helpful. My DIY experience with electricity is all residential, and I was pretty perplexed by those numbers. Thanks for the information. Still, from 208v to 185v is still a pretty big voltage drop. Perhaps someone undersized the wires or the wire or the run is VERY long to get that kind of resistance. 208v to 205v at the library seems much more reasonable.

    Come to think of it, the 220v at the RV park also shows a pretty big drop, and I guess that may explain the breakers tripping. Perhaps it is important to look at the I and V with a skeptical eye when assessing the reliability of a charging station.

    Live and learn.

    Andy
     
  4. drees

    drees Active Member

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    San Diego
    Definitely. At least with the S you can try different charge currents to see how much voltage sags under various loads, and possibly use that information to decide on a maximum charge rate.

    Yes, 220V is also very low, since typically you'd expect 240V on a single-phase install. Sometimes RV parks get 3-phase, so you can see 208V there as well. Most RV parks don't see the kind of load charging an EV at 40A presents - typically the biggest load they'd see is running the air conditioning on an RV. You should be able to get away with 20A on these problematic sites, but who knows.
     
  5. Eberhard

    Eberhard #421 Model S #S32

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    1,141
    Location:
    Germany
    for a charge it should not matter to be feeded by mono-phase 240V(70A) or 3-phase 205V (30A). unfortunately tesla denied this with the Roadster but we, in Europe are getting the 3-phase support with the Model S why not in the USA?
     
  6. J in MN

    J in MN S60 P12635

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    Jul 23, 2008
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    Minnesota
    Mostly because you are not going to find a 3-phase outlet anywhere in public in the US.
     

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