TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

Battery drain even while plugged in?

Discussion in 'Model S: Battery & Charging' started by kjl, Jul 8, 2013.

  1. kjl

    kjl Member

    Joined:
    Jun 4, 2013
    Messages:
    91
    Location:
    SF Bay Area
    Sorry if this is already covered in the forums. I thought with the latest software version, power would come from the wall (if plugged in) when the car is idle.

    I plug my car in at night, and it's scheduled to charge at midnight, and, usually it only has to charge about 20-30 miles of range (so it's probably done at 1:00 am). I have mine set to charge to 90%, which as I understand it should be a 188 mile charge. When I check it in the morning, it's usually down to 183 or (rarely), 184. Over the course of the next few hours (say after breakfast, shower, change), it'll be down to 181 or 182 already. This is while plugged in. Is this normal? I've been careful to click the FOB once after exiting the car after checking the charge the first time so that it shuts off the displays, climate control, radio, etc. so I don't think that's part of the problem.

    Thanks.
     
  2. dsm363

    dsm363 Roadster + Sig Model S

    Joined:
    May 17, 2009
    Messages:
    18,235
    Location:
    Las Vegas, NV
    #2 dsm363, Jul 8, 2013
    Last edited: Jul 8, 2013
    That's normal. From what I understand, it uses the wall outlet to power accessory systems when you ask it to (pre-cool car or you hop in and listen to the radio) but it doesn't stop the slow 'vampire drain' where you lose range with the car just sitting there. They are working on a software update later this year to minimize that drain. You could consider pushing your charge set time back to 4 or 5AM maybe at charge at 40A. Of course if you drive enough the day before where you wouldn't get enough range by the time you left in the morning then you can adjust that time or just charge on plug in when you got home. If you left the Model S plugged in for over 24 hours or so it will should back up at the next scheduled charge time but you want it to complete closer to when you leave in the morning which is why shifting your scheduled charge time back would help.

    This talks about the drain
    Power drain while idle (Vampire Load))
     
  3. kjl

    kjl Member

    Joined:
    Jun 4, 2013
    Messages:
    91
    Location:
    SF Bay Area
    Ah, thanks. Yeah, I saw that thread, and assumed that the latest software version would have fixed it, but I guess not. I am surprised that the drain is so fast - it's dropping about a mile of charge per hour, which seems quite fast (at least when it's charged in the 90% range - this afternoon it seemed to drop from 152-151 over the course of ~6 hours, not plugged in).

    I have my scheduled charge time set that early because a couple of times a week, I drive my car about 110-140 miles, and need a long multi-hour charge in the morning (and don't feel like switching the charge time every time I get home - would much rather plug and forget).

    Most ideal would be a setting that says "I want to be fully charged by 7:00 am, estimate charging time and start charging at the appropriate time."
     
  4. strider

    strider Active Member

    Joined:
    Oct 20, 2010
    Messages:
    2,917
    Location:
    NE Oklahoma
    We've been asking for this for awhile. Oddly, the RAV4-EV which uses a Tesla drivetrain has this feature. Someday....
     

Share This Page