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 and becoming a Supporting Member. For more info: Support TMC
Start a Discussionhttps://teslamotorsclub.com/tmc/tags/

DIY 12v replacement

Discussion in 'Model S' started by bleebdat, Jun 19, 2016.

Tags:
  1. bleebdat

    bleebdat Member

    Joined:
    Jun 14, 2013
    Messages:
    43
    Location:
    Baton Rouge, LA United States
    Sorry if this has already been posted, tried searching...Is there a walk through anywhere for replacing the 12v battery. -2013 model s 60
     
  2. bleebdat

    bleebdat Member

    Joined:
    Jun 14, 2013
    Messages:
    43
    Location:
    Baton Rouge, LA United States
    Bump.. nothing out there?
     
  3. Master One

    Master One Member

    Joined:
    Jun 19, 2016
    Messages:
    69
    Location:
    Linz, Austria, Europe
    Can't help, but I'd love to see a lithium based 12V drop-in replacement (assuming that Tesla is still using a large and heavy 12V lead battery). I've read that a lead battery may be mandatory by law depending where you are, but in an EV you do not need the power to operate an ICE starter. I've seen a report about such a lithium based replacement for a Nissan LEAF, which is smaller, a lot lighter, comes with own BMS and eliminates all the downsides of good old lead batteries. Of course there is a catch, namely the price tag.
     
  4. murphyS85

    murphyS85 Member

    Joined:
    Oct 12, 2014
    Messages:
    70
    Location:
    Horsham, PA
    The 12 volt battery is an AGM battery.
     
  5. zwede

    zwede 2013 P85+

    Joined:
    Jan 17, 2014
    Messages:
    480
    Location:
    Plano, TX
    Earlier this year I had the car at the service center for other reasons and they replaced mine under warranty even though I had no warning messages. I asked how come they replaced it and they said because it was so old (original battery from July 2013). So you may want to check if they'll replace yours for free also.
     
  6. mrElbe

    mrElbe Active Member

    Joined:
    Aug 17, 2014
    Messages:
    1,257
    Location:
    Stouffville, ON Canada
    Here you are:
     

    Attached Files:

    • Informative x 4
    • Like x 1
  7. bleebdat

    bleebdat Member

    Joined:
    Jun 14, 2013
    Messages:
    43
    Location:
    Baton Rouge, LA United States
    Thank you, thank you, thank you!
     
  8. Dborn

    Dborn Confirmed

    Joined:
    Aug 26, 2011
    Messages:
    2,393
    Location:
    Sydney, Australia
    AGM is still a lead acid battery.
     
    • Informative x 1
  9. strider

    strider Active Member

    Joined:
    Oct 20, 2010
    Messages:
    3,153
    Location:
    NE Oklahoma
    Bumping this thread as I just got the "12V needs replacement" message today and I'm out of warranty and service plan. I read through the PDF but don't see the procedure for disconnecting 12V power. Anyone have that? Is it just a fuse pull?
     
  10. mspohr

    mspohr Active Member

    Joined:
    Jul 27, 2014
    Messages:
    2,788
    Location:
    California
    You might look into this battery:
    BattMobile Batteries, Custom Lithium Batteries

    This is a LiFePO4 battery being developed by a Tesla owner as a replacement for the Lead AGM battery.
    He's doing extensive testing on it. Not sure if it's shipping yet. You'd probably end up as a beta tester.
    It's mentioned in a bunch of threads here... just do a search for Battmobile.
     
  11. rypalmer

    rypalmer Member

    Joined:
    Aug 22, 2014
    Messages:
    690
    Location:
    Canada
    Also - you can't charge them when they're cold. This is the real reason why Tesla still uses lead acid batteries. Otherwise they would require temperature management, and this would cause more vampire drain.
     
    • Informative x 1
  12. ev-now

    ev-now Member

    Joined:
    Jul 30, 2015
    Messages:
    449
    Location:
    Denver, CO
    Sean at Battmobile will answer any and all questions about this -he's worked hard to get an alternative available (I think it shipping now). Certainly my first stop when out of warranty on my CPO.
     
  13. sorka

    sorka Active Member

    Joined:
    Feb 28, 2015
    Messages:
    4,294
    Location:
    Merced, CA
    See this thread:

    Anyone using a LiFePO4 12 volt replacement battery ?

    I have my doubts that a lithium ion battery replacement would be better given the current battery charges and discharges a little more than half way 6+ times a day. Given the proposed capacity of that battery, I figured 1561 charge/discharge cycles in a year which should kill any lithium ion battery long before that.

    I still owe ElectricLove some data but have been swamped with work and trying to catch up with tasks at home that were neglected over the holidays.

    I've seen reports that Tesla parts will sell the battery only for about $122.
     
  14. mspohr

    mspohr Active Member

    Joined:
    Jul 27, 2014
    Messages:
    2,788
    Location:
    California
    This is a LiFePO4 battery which has a lifetime of several thousand cycles... much better than Li Ion batteries.
    If you can, indeed, get a new AGM battery from Tesla for $122 that would be a deal... anyone have confirmation of this?
     
  15. sorka

    sorka Active Member

    Joined:
    Feb 28, 2015
    Messages:
    4,294
    Location:
    Merced, CA
    But even then, what are we talking about, a little over a year? Is that better than the stock AGM battery?
     
  16. mspohr

    mspohr Active Member

    Joined:
    Jul 27, 2014
    Messages:
    2,788
    Location:
    California
    AGM batteries have about 500 cycles at 50% draw down. Much worse than the 3000 for a LiFePO4 battery.
    (I don't think the Tesla draws down 50%... probably more like 10 or 20 % to prolong the life of the battery... otherwise they would all die fast.)
     
  17. sorka

    sorka Active Member

    Joined:
    Feb 28, 2015
    Messages:
    4,294
    Location:
    Merced, CA
    Hmmm. Not buying that. Where's your source for that? Lead acid batteries degrade the longer they are left discharged not how many times they are cycled.

    Also the factory AGM battery is much higher capacity than the proposed lithium ion battery. Many are lasting two or more years.
     
  18. sorka

    sorka Active Member

    Joined:
    Feb 28, 2015
    Messages:
    4,294
    Location:
    Merced, CA
    Also, given the much flatter discharge curve of LiFePO4 and the smaller capacity, the proposed battery will be nearly drained before the contactors kick in to recharge it, not 50%. 50% is what happens to the current lead acid battery and the reason it kicks into recharge it is because the voltage drops below a threshold. That same voltage threshold won't be reached on the LiFePO4 until it's almost empty.
     
  19. sorka

    sorka Active Member

    Joined:
    Feb 28, 2015
    Messages:
    4,294
    Location:
    Merced, CA
    Doing a little reading on LFP batteries. I keep seeing that they should cost a lot less per wh than lead acid batteries. If true, then I'd agree that they could be a good replacement for lead acid batteries. But at the capacity and cost of the one I saw in the other thread, it's not there yet. The ebay price was the deposit, not the actual full cost of the battery.
     
  20. jplasmd

    jplasmd Member

    Joined:
    Apr 16, 2015
    Messages:
    24
    Location:
    Las Cruces, New Mexico
    Here is the answer to your question. It's a video on the 12v battery replacement on the earlier Teslas:

     
    • Helpful x 1

Share This Page