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Variable Charging Rate

Discussion in 'Model X: Battery & Charging' started by Xmama, Jan 30, 2016.

  1. Xmama

    Xmama Member

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    My P90D with 72 amp onboard charger will be my first Tesla, so I have no past experience with charging. I'm wondering if you can tell the car at which rate to charge. I will have the High Power Wall Charger on a 100 amp circuit. If I don't want to charge at the full capacity of the wall unit all the time, can I dial it back with any controls in the car/touch screen/iPhone app? Total newbie question, I know.
     
  2. pvogel

    pvogel Member

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    Yes, you can tell it what rate to charge at. More importantly, by default it will only charge to about 80-90% in order to keep the battery in the best possible condition. Once it finishes charging it will continue to draw a small amount from the charger to power all the onboard electronics so the battery doesn't run down unnecessarily. The advice from Tesla is to leave the car plugged in all the time at home.

    If you are planning to go on a road trip and need the range, you put the charger into 'range mode' and it will charge it to 100%, from there you should start driving it within a few hours.
     
  3. Xmama

    Xmama Member

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    So, just to be clear, there would be a menu where I could tell it to charge at 3 amps or 12 amps or 57 amps or 72 amps if I wanted?
     
  4. Rocky_H

    Rocky_H Member

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    Good to get these questions out there. Yes, you can set the charging current manually from the touch screen, and it will even store that setting associated to that location, so whenever you charge at that place, it will automatically use that same setting, so you don’t have to remember to do that every time. What you are suggesting is a decent idea that many people do. Running power electronics at their maximum level all the time usually makes them run a bit hot, and a lot of heat is the main thing that shortens the eventual life of electronics. On the mobile charger of my Model S, I use about 32A, instead of the 40A maximum, because it does get a little hot at that level. I’ve used 40 sometimes when I’m out on a trip, when I wanted the extra charging speed, but there’s no need for that every night when I’m sleeping at home.
     
  5. stevezzzz

    stevezzzz R;SigS;P85D;SigX

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    Yes.
     
  6. pvogel

    pvogel Member

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    I don't know that it's quite that granular. You can definitely dial it back from 72 to 48, 40. Why would you want to charge that slowly? Even at 72A you are charging the battery at about .25C, lithium batteries are happy charging at about 2C, a supercharger hits at 1.5C
     
  7. Rocky_H

    Rocky_H Member

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    Right. There is a screen you can bring up relating to charging (I think it’s a little lightning bolt icon at the top of the touch screen). On that screen, you can change several settings. What target level you want the battery to charge up to, what current level you want it to use, whether you want to have it wait until a certain scheduled time to begin charging, etc. The current setting only goes down to 5A on the Model S; probably the same on the X. But you really won’t need to back off as low as 3 or 12 like you were talking about. That’s basically just going to waste more energy because it does use some overhead of energy to run the charging circuit, so you would be running that a lot longer if you turn the current way down. If you want to back off from 72A, somewhere in the 50’s or 60’s would be fine, and there’s not much reason to go all that much lower.

    Also, I know you are asking about the X, but for most of these basic systems like the charging setup, almost all of it is going to be about like the Model S, so you could probably learn about most of this by checking in the Model S sections of the forum where there is a lot more information already there, and you can use the search on this forum to find answers to some of the other questions you may have that probably aren’t answered specifically in the Model X section.
     
  8. CSFTN

    CSFTN Member

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    That screen pops up automatically every time you plug in, at least to a HPWC. Can't recall definitively about the UMC, but I would assume so as from the perspective of the car its the same. Except the max amp.s of 40 instead of 80.
     
  9. pvogel

    pvogel Member

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    Max of 48 Amps (standard charger) or 72 amps (high amp charger) on the X
     
  10. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    Exactly. For example, I often set the max current to 56 Amps on my 100/80 Amp HPWC to cut resistive losses in half and to be nice to the grid.

    My only complaint is that once you have limited the current, you can only reset it in the car. I would really like to adjust max current, just as I can adjust the maximum charge level (80, 90, 100%), via the App and not have to go to the car.
     
  11. vangogh

    vangogh Member

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    SuperCharging Rates on the X

    I did a supercharge this morning from near fully discharged (35miles battery left)...
    45degrees outside with climate and heated seats on after a 20 minute drive...

    Hope this helps

    time battery charge rate charge in last 5 minutes

    0min 35 miles 290mph
    5 min 60 miles 310mph 25 miles
    10 min 83 miles 297mph 23 miles
    15 min 102miles 280mph 19 miles
    20 min 119miles 262mph 17 miles
    25 min 134miles 247mph 16 miles
    30 min 148miles 234mph 14 miles
    35 min 160miles 222mph 12 miles
    40 min 172miles 210mph 12 miles
    45 min 182miles 200mph 10 miles
    50 min 191miles 191mph 9 miles
    55 min 200miles 182mph 9 miles
    60 min 208miles 180mph 8 miles
    65 min 216miles 179mph 8 miles
    70 min 223miles 178mph 7 miles
     
  12. TexasEV

    TexasEV Active Member

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    I will cross-post my reply to your cross-posted post. This is not the charging rate at that moment, as the car displays the car displays the average charge rate of the session in miles of range/hour, not instantaneous rate. For instantaneous charge rate you need to use the kW display.
     

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