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Charge Daily or Charge as needed?

Discussion in 'Model S: Battery & Charging' started by Barryfins, Aug 3, 2014.

  1. Barryfins

    Barryfins Model S Owner

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    I'm a happy MS owner that wants to get your input.


    The Tesla Model S owners manual says keep your Tesla plugged in whenever you can. My service advisor said charge at different milage intervals and if you only need to charge once a week that is OK...


    image.jpg image.jpg
    What are your best practices?
     
  2. invisik

    invisik Member

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    Charge nightly. Set the slider to how many miles you'll really need (eg somewhere in the middle).

    -m
     
  3. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Just treat like an iPhone. Plug it in at night, and it will be where you set it to in the morning. Starting every day with a full tank means you never have to think about whether you can get there or not.
     
  4. GoBlue88

    GoBlue88 Member

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    I charge to 60% every night.
     
  5. dhrivnak

    dhrivnak Active Member

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    With the Roadster if you do not charge to 83% then your pack will never balance. So at least with the Roadster charging to 60% will hurt your battery and decrease range.
     
  6. GoBlue88

    GoBlue88 Member

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    With the MS battery pack, that doesn't appear to be an issue.
     
  7. AEdennis

    AEdennis Active Member

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    I've done a lot of max charges and the pack went from 265 rated to about 260... 17,000 miles... Ideal miles were closer to 305, now around 300.
    My 90% had been around 236 rated to about 232.

    I probably will drop it to 80-90% of total and see if that helps.
     
  8. caddieo

    caddieo Member

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    I plug it in nightly and it is programmed almost all nights to start at 0030H. I set the limit on the slider anywhere from 120 to 220 miles depending on my next day's agenda. On one day with an unscheduled trip to Orlando, I simply topped off at Port Orange and on another unscheduled trip to Jacksonville, I topped off at St. Augustine. Love my location in relation to those two SC's.
     
  9. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Bear in mind that for long term storage 50% is best for the battery. For driving it's best not to go under 50% because the cells heat up more for a given amount of power when under 50% as opposed to over 50%. Now the cooling system will keep this from being a real issue, but it will still take a bit more energy as the cooling system will have to work harder. Myself, I charge to 75-80% and then will drive down to 50-60% on a typical day.
     
  10. brianman

    brianman Burrito Founder

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    Like a cell phone. I'm not real good with iPhones. ;)
     
  11. flashflood

    flashflood Member

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    Likewise. I charge to just over 200 rated miles every night. On a normal day I'll only drive about 50 miles, but if I have an unexpected need to drive someplace an hour away with no destination charging, it's no problem.

    Tesla really nailed this: 200 miles is the magic number. That's four hours at an average speed of 50mph, and it's just not very often you need to drive more than four hours in a day.

    (50mph is about the best you can do even if much of your drive is at 80mph -- Amdahl's Law strikes again.)
     
  12. GoBlue88

    GoBlue88 Member

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    I rarely drive over 40 miles a day. So I'm always between 40-60%.
     
  13. linkster

    linkster Member

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    Someone on Twitter asked Elon:

    "My daily commute takes about 50% SOC. What would be best for the battery long term..90%->40% charge daily, or 80%->30% ? (85kWh)"

    Elon's response:

    "80% to 30%"
     
  14. Plug Me In

    Plug Me In Member

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    I plug in every night in winter (car stays outdoors) ; I figure battery is happier this way. Warm weather I top off to 75% every 2-3 days.
     
  15. Pilot_51

    Pilot_51 Member

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    Same here, charge to 80% and typically drive 45 miles down to 50-60%.

    Can we have a calculator or something for this so we know the optimal charge limit for our own commute? Or, would it be a simple answer like 50% in the middle (75% to 25% in his case)? And yes, I know there's a complex answer too, like how long it stays at a SoC and the temperature and all that, but a general answer is a good place to start.
     
  16. David99

    David99 Active Member

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    Out of balance battery packs doesn't hurt the battery, it just limiting the battery to the cell that is at lowest. Out of balance doesn't hurt the battery. Keeping it at a high state of charge does, though.
     
  17. GoBlue88

    GoBlue88 Member

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    Don't know of any scientific evidence to back this up, but it seems like the answers I always get are to keep 50% as close to the middle as possible.
     
  18. glhs272

    glhs272 Unnamed plug faced villian

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    Might also consider the Depth Of Charge issue. To minimize DOC, charge every day or as much as possible.
     
  19. AnOutsider

    AnOutsider S532 # XS27

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    I do a bit of both. If I get home with 220m on the dash, and know I'm just going to work or around town tomorrow, I'm not going to plug in. Under 120m or knowing I have somewhere to go, then I plug in.
     
  20. Me2

    Me2 New Member

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    Is there really a Depth Of Discharge issue? I doubt that discharging five times from 80 to 70% is any better than once from 80 to 30%. Probably the contrary.
     

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