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P100D usable battery capacity

Discussion in 'Model X: Battery & Charging' started by Evil.Labrat, Nov 13, 2016.

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  1. Evil.Labrat

    Evil.Labrat Member

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    Hauling a loaded trailer in an XP100D from the Dalles, Oregon to Kennewick, Washington.

    Started at the Dalles SC at 98% and ended up at 1% at the Kennewick SC.

    The reported energy consumption was 89.3kWh after 131.3 miles. So with 97% used that puts the useable capacity of this pack with about 2k miles at approximately 92kWh.

    Kennewick wasn't part of the plan, but I lost the truck I was drafting behind to a rest area and it wasn't looking good for making it to Pendleton. It's a charging desert out there.
     

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  2. LargeHamCollider

    LargeHamCollider Battery cells != scalable

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    Pulling a trailer will distort your measurement somewhat because the higher load imposed on the batteries will slightly increase voltage sag, slightly decreasing total energy available. I'd add a kWh or so to your number to correct for this, am too lazy to run the numbers right now.
     
  3. qadaemon

    qadaemon Member

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    How do you show lifetime on the trip display?
     
  4. Evil.Labrat

    Evil.Labrat Member

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    Under Controls > Trips tab in v8.0 you can name Trip A and Trip B to something friendly by tapping and holding until a name box shows up. Then there is a check box next to it that will make it show up on the instrument panel when you have the Trips app selected.
     
  5. ReddyLeaf

    ReddyLeaf Member

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    Wow! I think Tesla will need to rewrite the rules for SC distance, especially for towing! Arriving with 1% in Kennewick means that you climbed a significant hill, then coasted down to the SC. I've done that hill both with a Leaf and Tesla, including with bicycles on the back. Welcome to our "charger desert", just be glad you didn't try it with 5 yo Leaf.;)
     
  6. qadaemon

    qadaemon Member

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    Gotcha, thanks. I haven't tried renaming those and thought there was a setting I missed :)
     
  7. Evil.Labrat

    Evil.Labrat Member

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    Yeah I hadn't gone that way before and when I saw the hill up in front of me I did my best Tesla Bjorn impression (sheeeit). I'm somewhat curious if someone at HQ looks at the charging data and stuff like starting charging at 1% gets a look over with the car's logs. I ended up diverting to Kennewick because the estimated battery for Pendleton was switching to an exclamation point and Kennewick said I'd have 15% left over (I showed it!)

    The two spots I had range issues was between The Dalles, OR and Pendleton, OR which I think I'll try again with another load, and then also from Twin Falls, ID to Tremonton, UT. I had to roll up to Pocatello, ID first and then down to Tremonton, UT. I don't think I can make Twin Falls to Tremonton direct work with a similar load unless the temps are good and I find a slower moving truck to draft behind. The car was crazy thirsty!

    There seems to be some L2/L3 charging infrastructure in Arlington, OR, but this time I was past this before it started looking a little grim for Pendleton, and I don't have a CHAdeMO adapter for the L3 so the L2 would have been less than fun. At least with infrequently used SCs like we have out here, pulling a trailer in to charge without unhitching is quite doable, but other L2/L3 chargers who knows as they aren't standardized.

    But for the other problem area there is pretty much no charging at all that I can find from the I-84/I-86 interchange down to Tremonton. If they go back and start filling out routes with more SC's in a later phase, somewhere around Sublett, ID might be a good spot between Twin Falls and Tremonton geographically, but there's very little there except a gas station and some llamas.

    I rolled out of Twin Falls at 100% and had done some calculations of where I had to be before I got to that interchange to know if I should attempt Tremonton and I was easily 10% under where I needed to be. I believe on that portion I was traveling at 60mph with no trucks for miles to draft behind, temps in the low 40s.

    For those curious, here is a log of my SoC's for each leg with the trailer. After my first leg close call I decided to charge longer than probably necessary so I wouldn't get stranded.

    P100D towing loaded 5x8 cargo trailer (unknown gross weight, maybe about 1.5 tons):

    98% The Dalles -> 1% Kennewick [89.3kWh]
    80% Kennewick -> 23% Pendleton [52.4kWh]
    95% Pendleton -> 21% Baker City [68.0kWh]
    90% Baker City -> 6% Boise [77.9kWh]
    99% Boise -> 15% Twin Falls [77.9kWh] (two legs in a row with exact same usage)
    100% Twin Falls -> 15% Pocatello [79.8kWh]
    82% Pocatello -> 11% Tremonton [65.7kWh] (stupid truck ICE'd center stall making for an interesting time getting in without unhitching).

    All of the stops after Boise were after sunset and the temperature dropped into the low 40s and I started getting some "you should charge soon because of low temps" warnings.
     
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  8. ohmman

    ohmman Maximum Plaid Member

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    Wow. That's 680Wh/mi with nearly no elevation change. That doesn't compare well to other towing reports. What was your average speed?
     
  9. Evil.Labrat

    Evil.Labrat Member

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    Average speed I believe is 62.5mph, for most of the way from the Dalles until the Boardman rest area I was drafting behind a truck at I believe 71. I was using various following distances, but I think I was at 4 most of the time. These were essentially new tires and I'm not sure how long they take to "break in." It already seems like my no-trailer Wh/mi is lower than what it was before the trip, but maybe that's just psychological after seeing well over 1500 Wh/Mi often. :) Heading back the other direction today sans trailer, but I have the advantage of elevation this direction.

    If anyone has any data on the effectiveness of drafting at a higher speed vs. traveling slower with no drafting, that would be interesting to dig into.
     
  10. vandacca

    vandacca ReActive Member

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    I had to do an unexpected 200km (return) trip or 124 miles at the end of a day full of travelling. Needless to say, I didn't have enough charge for even the outbound leg. So I charged up at home just enough (35 minutes) to get to a supercharger. I decided to experiment with the rated mileage and see if I could obtain the predicted range. It was raining a little on the outbound leg. I drove on AutoPilot whenever possible (~90%) and followed the recommended speed. I kept getting warnings that I needed to drop my speed below 95km/hr, then 85km/hr and finally 80km/h (which I followed). Suggested speed eventually crept back up to 85km/h and I arrived with about 4% battery.

    I supercharged enough for the trip back plus a healthy margin. It wasn't really raining much on the way back, which would have lowered energy consumption somewhat, but I decided to draft the whole way back home (trucks and large busses). Again, I used AutoPilot (distance set to max 7) and I was averaging about 115 km/h and reached speeds as high as 120 km/h. I don't recall the actual numbers, but despite the increased return speed, my kwh/km was less for the return trip.

    I was shocked how much of a difference drafting made, especially at follow-distance set to 7. Rain did play a part, so taking into account the rain, I would guess that drafting allowed me to drive approximately 20-25 km/h (12-15 mph) faster for the approximately the same energy usage. Very rough numbers.
     
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  11. TheJMan

    TheJMan Member

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    So do we know the actual usable battery capacity now?
    It seems to be roughly 92kWh usable from the tests above and therfore 96kWh total capacity (if 4kWh buffer like other packs)
    I havent found anyone else test this.
     
  12. LargeHamCollider

    LargeHamCollider Battery cells != scalable

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    Towing will reduce total energy available due to voltage sag, probably by a few percent.
     
  13. TheJMan

    TheJMan Member

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    Good point.
    Hoping someone sees this thread and tests with their p100d. Thanks too wk057 we know the real capacity of all packs but sadly not the p100d, and considering the p100d has been out for a while now im amazed no one has tested it yet, or again.
     
  14. AWDtsla

    AWDtsla Active Member

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    Voltage sag should not matter. Trip meter is supposed to be measuring consumption. If it's being lost as heat inside the pack, it's still consumption, just higher than normal consumption per mile.
     
  15. LargeHamCollider

    LargeHamCollider Battery cells != scalable

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    I don't see a reason here to think that voltage sag is not relevant...
     
  16. AWDtsla

    AWDtsla Active Member

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    It's not. Your efficiency goes down as voltage sag is present in any part of the system, from internal resistance of the cells to any conductor external to the cell. The energy is not lost. That should simply be reflected the the amount of energy consumed. Take for example voltage sag while in ludicrous mode. Let's say it's 100V @ 1600A. That's 170kW being lost as heat somewhere between inside the cell and the inverter? Should not the car count that as energy used?

    Clearly, this is not the case with the trip meter.
     
  17. LargeHamCollider

    LargeHamCollider Battery cells != scalable

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    Do you *know* that Tesla is counting energy lost to internal resistance in the trip meter? I'm not saying you're wrong or that it's impossible but if it's true it's news to me.

    Also you say it's clear but the above post doesn't make it at all clear that Tesla includes energy lost to internal resistance. Do you know what sensors/data Tesla uses to generate the trip meter figure? Knowing that information would make it clear.
     
  18. AWDtsla

    AWDtsla Active Member

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    It's not counting a large proportion of energy, whether that's because of voltage sag or internal resistance or other is besides the point, really. It doesn't work right, hence it's 2017 and we're still talking about why someone can empty their range and end up with a kWh consumed that doesn't make any sense.
     
  19. Quesder

    Quesder Member

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    100D is going to make Tesla a fortune because people will definitely upgrade to that.

    Man, I am mad however, kind of realized the feeling of those who bought non-AP 2014 Model S.
    This is what my owner adviser told me: (note that I am renting a car during the wait and you know that it costs $700+ a month)
    "
    back in the office tomorrow. I know it will delay you cars production and you may be subject to a modification fee and we would lose the ability to build the car with ventilated seats. Will share an update tomorrow.

    Thanks,
    Josh
    "

    Man what should I do... I guess I won't need the extra 38 mile 95% of the time, but....
    The $10,000 75D->90D upgrade really makes me like an idiot now.
    Only if Tesla will provide a battery upgrade for $5000 10 years later.
     
  20. TheJMan

    TheJMan Member

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    So according to wk057 its 102.4kWh with 98.4 usable, respect, thats pretty awesome.
     

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