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First Drive of our new Tesla S 75D; and subsequent trips; Supercharging Speeds

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This charge thing has gone crazy,
Sunday am, i plug in, 50 miles left, rate 72kw
Sunday afternoon, 50 miles left, 134kw rate and cars sounds like it will explode
Tuesday noon , 50 miles left, 34kW rate, takes hour
Service center says all is fine
Whisky tango foxtrot.
Same super charger
Local SC says my dual chargers will only work if I install 100 amp outlet at home?
 
The Supercharger does not use the on-board chargers, the single at 40 amps or dual at 72 amps. Only 120 volt and 240 volt EVSE's utilize your on-board chargers, and yes, anything less than 240 volt and 90 amps will not give you the full charge speed that your dual chargers can achieve. You do not say which Model and battery size you have, but I have learned that the 75 is limited to 100 Kw but the 90 & 100 can use the full 120 Kw of the Supercharger. I did not know that any of the Supercharger units could go over the 120 to the 135 Kw rate you experienced on Sunday afternoon. The sound you were hearing was the BMS trying to keep the battery from over-heating as that much electricity is being dumped into the battery that quickly.
 
Local SC says my dual chargers will only work if I install 100 amp outlet at home?

Yes you need 100A / 240V circuit and a Tesla High Power Wall Charger ("HPWC") to use dual chargers at 72 amps. However, we rarely charge at the 80A maximum rate that our inventory 2015 P85D that came with dual chargers allows even though its connected to a 100A Tesla HPWC. When we've been on road trips we've only found 2 destination chargers which could provide more than 40A even though most were Tesla HPWCs. Unless you have a limited amount of time to charge at home, dual chargers aren't of much benefit IMHO. However the Tesla HPWC lets us leave our UMC cable in our Tesla instead of having to get it out and putting it back every time we charge. Plus the pulsing green LEDs are really cool looking.
 
The closest I ever got was this (the grey line was what the car was estimating, colored line is actual usage - Mitchell SC to Murdo SC, 65 degrees and sunny all the way, extripplanner told me to charge >90%, so I did) :
View attachment 227501

What I think kills the in-car estimates is it assumes 65mph top speed.
got me thinking... has anyone actually needed a tow because you ran out of juice? Any horror stories out there?
 
got me thinking... has anyone actually needed a tow because you ran out of juice? Any horror stories out there?
I think most people just slow down once the car starts showing negative battery percentage on arrival at SC. I had one such situation where an exit to a supercharger was closed for roadwork, so I had to go an extra 10 miles to the next exit and then back (the exit from the opposite direction was open) - so 20 extra miles. Drove it below speed limit but most of it was construction zone so I was supposed to (though some people behind me may not have thought so).
 
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I posted previously that we purchased a new Model S 75D from inventory from Denver, CO. We flew from San Diego, CA to Denver Tuesday morning, 5/16/17 to pick it up from the Denver Service Center. We did all the paperwork, got the instructions, then left for San Diego for what turned out to be a 26 hour trip. We took our time along the way, starting with over an hour lunch at a Mexican restaurant down the street from the Service Center.

We made it back from Denver to San Diego with no problems. We got back home around 2pm yesterday, Wednesday, after a "fill-up" at the Temecula, CA Supercharger. We left the Tesla Model S 75D set at 90% because there is no need to wait around for the extra time to get that last 10% anyway. We only missed the one Supercharger in north Las Vegas because we wanted to stop at the one close to the airport, Las Vegas south. We would stop it at 80% then on to the next station. We very much enjoyed our drive, meeting many other Tesla owners. We ended up spending more time at most stations than we had planned just chatting with the folks.

We found ourselves driving much faster than we had planned, just following the flow of traffic. We LOVE the AP2. It took some getting used to but eventually we both learned to trust it to make the curves by itself without us taking over. We were set for 7 car lengths spacing but eventually realized that we will need to change that, maybe try 3 and see how it goes. The auto lane change is great. The car already had the 17.17.17 update installed. We do hope that future updates will help to smooth out the driving around curves, but the jerking was not too bad, considering that we could just let it go and do it's thing and still get us home safe.

We only had one leg that gave us worry. We had stopped the charge at 70% in Green River, UT, thinking that the rated 181 mile range would be enough to get us the 124 miles we needed with a little reserve until the next Supercharger in Richfield, UT. After all, we did have 57 miles more than we needed, right? Well, what we did not (read that to mean me, not my wife) account for was the terrain and wind. We were happily driving along with AP going 80 mph up, then up, then up some more. There is a lot of high mountain passes on this route. Beautiful though it was, even at night, it is very high. Also we were experiencing very strong head winds. Now in the usual rented cars we take our cross country trips in we can feel the wind, hear it even. NOT in the Tesla S. It was so smooth and quite. Such a joy to drive in. Okay, back to the story. Anyway, we were happily driving (meaning me for this leg), using the AP2. Every once in a while I would check the Remaining Miles, and compare it to the miles needed to drive to get to the Richfield, UT Supercharger. I began to notice that our reserve of 57 miles kept reducing. Then the GPS on the touch-screen, along with the dash GPS started giving me the message that I needed to slow down to 60 mph to make it to our next stop. Well when did I ever listen to sound advice. I was not going to let some computer tell me what to do. So on I drove at 80 mph (this was the posted speed limit, by the way), but I was continuing to watch the dwindling reserve while AP2 was continuing to safely drive us along the freeway. Eventually I started having visions of spending hours waiting on a tow truck, in the middle of the night, just to drag us to the next Supercharger. Therefore when the reserve reached 30 miles I slowed down 5 mph, to 75. When the reserve reached 25 miles I slowed down another 5 mph, to 70. This was a little better, but it kept dropping. By this time we were past the summit and on our way down so it should give us lots more range. However, the headwind was not helping us at all. At 20 miles reserve another 5 mph reduction to 65 mph. We were lasting longer at each reduced speed, but still losing reserve. At 15 miles reserve I slowed down another 5 mph to 60. By this time I was wishing that we had waited the extra 10 minutes to charge from 70% to 80%. That extra 25 rated miles would have been useful. Even at 60 mph we were still losing reserve because of the headwind. At 10 miles reserve I again slowed down another 5 mph to 55 mph. As a side note, we do love the AP2 speed adjustment of 1 mph and 5 mph. It makes it so easy to adjust speed. Finally at 55 mph we were able to get better efficiency than rated so the reserve started to grow. I though about increasing speed but decided that the extra time driving slower was not worth the risk of not getting to the station. Well Hallelujah, we made it to the Richfield, UT Supercharger station with a whopping 22 miles remaining (8% of battery). From then on we charged a minimum of 80%, except at Las Vegas south we stopped as soon as we got back from the bathroom and the car was at 66%. We only had 36 miles to Primm, NV. At Primm we went to the McDonalds for breakfast so the car was almost 90% when we returned. We waited a couple of minutes for it to finish, then left for Barstow, CA., 119 miles away.

Overall, we are very happy with our new Tesla, and are looking forward to the next 15,000 miles or so of trips we will be using it for in the next 3 months.

Concerning the Supercharger speeds, I was looking forward to getting 120Kw for the first 50% of charge, but was disappointed. It must be with the 90 or 100Kwh models that get that speed. The highest speed we got was 99kw, but usually 97 or 98kw below 50% battery charge. From above 50% the speed dropped. I tried to record speed at each 5% mark but missed some when we left the car to eat or use the restroom. I will continue to plot our Supercharger speeds as we continue our travels in the next few months. We did notice that every Supercharger was different, but within a close range of speed. I will post what data I have now.

Below 50% charge: 96 to 99Kw
55% - 80 to 87Kw
60% - 72 to 81Kw
65% - 64 to 78Kw
70% - 56 to 66Kw
75% - 43 to 56Kw
80% - 36 to 44Kw
85% - 29 to 36Kw
90% - 25 to 30Kw
I will update this list as more data is gathered on our next trip.

The slowest charge, and the station furtherest from the freeway, was St. George, UT. Also at St. George we were not able to find restroom until the Starbucks opened up at 5am. Because of this we stayed plugged in until the full 90% charge was achieved while we were away from the car. The GPS got us to every station, but we did have to search in the dark before we saw a few of them. Still, overall we were very happy with our experience.

On a side note, we have learned to use "Hypermileing" techniques driving our Leaf. We try to drive only 55 or 60 mph on the freeway, Occasionally we go faster, but only if we are in a big hurry and a short trip. With the Tesla I thought about trying to limit our speed to 60 mph on the trip back to conserve energy. However, since I needed to get back home to teach a class Wednesday night I felt it best to give the Tesla a real world test run. Most drivers of gas cars seem to push the limit of speed. If EVs are to gain general acceptance then they must meet these needs, even if that is not the most efficient method. Very few drivers are thinking about conserving. They just want to conserve their time and never mind what fuel or energy they waste. Because of this, I set the Tesla limit at 5 mph over speed limit. However, on the entire trip our fastest cruising speed was 80 mph.

We are looking forward to our next trips:

Tomorrow, Friday, 5/19/17 and Saturday from San Diego to Disneyland with the kids and grandkids with a stop at Santa Ana Supercharger on the way up, and San Diego Supercharger on the way home.

Memorial Day Weekend a drive up to San Francisco area for the weekend with multiple stops each way.

Two week cross-country trip to Ohio, then Georgia and Florida, then back home to San Diego by July 4th.

Mid August One week trip to Pacific North West, including WY, then return to San Diego.

I will continue to track our charging speeds for all three of these trips and report back on this thread.
Just FYI, the charge rates for my 75D are exactly the same as yours. I'm in Australia.
 
Agreed. I did not realize this until someone on the forums mentioned it. Annoying!o_O

From Telsa:

Hi John,


Thank you for your email. The Model S and Model X are able to accept 120kW from the Superchargers no matter the battery size. 120kW is simply the max amount of power exerted from the Supercharger that the vehicle battery is able to tolerate.


While the Supercharger is capable of charging the car up to 120kW, the car and the chargers are in constant communication to decide what is best for the car’s battery based on over cell health, temperature, current state of charge, how many other cars are plugged in to the Supercharger, etc. For longevity of your battery, the technology will always know what is best for the vehicle’s particular battery.
 
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I was disappointed to learn that the 75D cannot charge at 120kW as well. This was never said to me at any point during the purchasing process and I never saw anything about it online. The Supercharger page made zero mention of it. The highest rate I've been able to achieve is 92kW. Lately I am unable to top 87kW.
Just finished a 4000 mi WA to WI trip and routinely saw 104-106KW (initially) with a 2015 70D. Even saw 108-110KW a few times. Granted, this was after driving 80 mph, arriving at 5-10% SOC and 4-5 charges per day, at moderate temps. There has definitely been a change in the algorithm for charging: starts at zero, checks, ramps up to about 10 KW, drops or holds, ramps again maybe stopping around 30-35 KW, then bumps up to maximum, quickly dropping back down 5-10 KW in just a few minutes. Of course, all of this is temperature, SOC, and charger dependent. At one SC I wasn't able to charge even after several plug/unplugs. I was only able to charge after another Tesla proved the stall was working, and I re-booted (not sure which one helped).
 
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Yea, 80 is boiling hot for me (usually set to 66) but once, once on a trip, I was parked outside and it was in the 40's in the morning, so I turned it on Max Heat for over an hour while still at the hotel (had to restart it a couple of times) knowing I need to charge at a nearby SC before going on the next leg. Sadly, while I managed to melt some chocolate that I was snacking on during the trip, the battery stayed super cold - when I got to the supercharger it was trickle charging for a bit (sub 10KW for the first 15 minutes at least IIRC). I should have supercharged the night before instead, lesson learned.
Curious - did you have range-mode ON when you were heating your cabin remotely? I believe with range mode ON, the battery heating is minimized except when the battery temps are quite low. Don't know the details, only have faint memory...
 
Just finished a 4000 mi WA to WI trip and routinely saw 104-106KW (initially) with a 2015 70D. Even saw 108-110KW a few times. Granted, this was after driving 80 mph, arriving at 5-10% SOC and 4-5 charges per day, at moderate temps. There has definitely been a change in the algorithm for charging: starts at zero, checks, ramps up to about 10 KW, drops or holds, ramps again maybe stopping around 30-35 KW, then bumps up to maximum, quickly dropping back down 5-10 KW in just a few minutes. Of course, all of this is temperature, SOC, and charger dependent. At one SC I wasn't able to charge even after several plug/unplugs. I was only able to charge after another Tesla proved the stall was working, and I re-booted (not sure which one helped).

/Jealous

Thankfully Tesla is finally taking this seriously and has agreed to take a look at my car this Friday at the Seattle service center. Will report back if I learn anything significant.