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Third Party Roadster Pack?

Discussion in 'Roadster' started by ElectricLove, Sep 24, 2015.

  1. ElectricLove

    ElectricLove Member

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    Third Party 1.5 Battery Replacement???

    Here is a thought;

    At my company we are working on developing a custom-built battery department. I am quite confident we could take a Roadster pack and built new battery sheets for it and install them in the existing space using the same dimensions.

    We would need someone willing to be our guinea-pig of course. The ending result would be 75kwh pack and at this point it would be conceivable that our price would be right around $30K for that pack. We would be using LG HG2 cells for your reference (they are 3,000 mAh 18650 cells which are rated for high discharge of nearly 7C, meaning the entire pack would be "rated" for 430kw discharge, which is almost double what the Roadster really pulls at peak, therefore the temperatures should stay lower than in the standard set-up).

    I know there is at least one "dead" 1.5 in the Phoenix area and that may the perfect candidate for us to rebuild.

    If we got a committed party we could start the process and it would probably take about 2 months to get us tooled-up and have the new pack ready.

    Any interested parties?

    The main benefit for us is that we get a nice bulk of battery cells to add to our initial PO, which brings our cost per cell down, making our business plan more feasible!

    Please email me at [email protected] if interested, I don't get on the forums much anymore since I sold my Roadster...
     
  2. ElectricLove

    ElectricLove Member

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    Third Party 1.5 Battery Replacement???

    Here is an alternative option:

    A 3rd party battery replacement program!

    My company is looking at developing a custom built battery program using the 18650 cells just like the Roadster... A couple Roadster 1.5 battery pack rebuilds would be a great experience for us to launch our new program and provide a fix for this need...

    If interested in discussing this further with me please do email me at [email protected]
     
  3. ecarfan

    ecarfan Well-Known Member

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    Roadster 1.5 prices if there is no 3.0 upgrade

    Thank you, that is an interesting proposal, but here is my concern: if I had an aftermarket battery installed in my 1.5 and then at some point in the future I had a problem with my PEM, it is conceivable that Tesla could refuse to fix or service my PEM saying that they could not guarantee their work because the battery could be responsible for the PEM problem and it could recur.
    I am simply hypothesizing here. I am not an automotive engineer or electrical engineer. I am not saying that you could not build an excellent Roadster replacement battery. I am just concerned about maintaining my Roadster long term, and the possible complications that could arise from having aftermarket and not "Tesla approved" parts installed in my car.
    Now if you could work with Tesla in developing your replacement battery and I had a statement in writing from Tesla saying that your battery was an "approved Roadster replacement" part, then I would be very interested!
     
  4. ElectricLove

    ElectricLove Member

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    3rd party that would like to offer a battery pack rebuild to Roadster owners

    Hi, I work with a company in Phoenix, AZ and one of our upcoming projects is to begin building custom battery packs using 18650 cells.

    It would be a great opportunity for us and potentially a great opportunity for a 1.5 Roadster owner if we teamed up and we rebuilt your battery pack.

    I will be transparent and up-front with you, I have experience working on the Roadster, I've serviced the PEM and rebuilt the front end of one, however we have not formally done a battery pack rebuild, so you would be a bit of a guinea-pig, however if you are in need of the new pack perhaps this arrangement would be worth the risk for you.

    The cells we will be using are LG HG2 cells, they are 3,000mAh cells and if we rebuild the pack in an identical arrangement as the existing pack it would provide about 75kwh of battery capacity and be more than capable of reaching peak discharge current of the Roadster well within the specifications of the battery (about half of max discharge rating actually!)

    I estimate the cost to be $30K and if we have someone committed to working with us I will promise them that their price will NOT exceed that amount, if our internal cost does (and I suspect it will), we will write the difference off to R&D costs.

    This is a potential win-win, it would help us to create a larger initial battery cell PO and provide us with a large order to fine-tune our process. And you get a new battery pack that Tesla doesn't offer.

    Please email me at [email protected] with any specific questions if you are interested in pursuing this opportunity with us.

    We are in Phoenix, AZ so we would need the vehicle here to uninstall the pack, rebuild the modules and then reinstall the pack. My anticipation would be a 2 month timeline on getting the cells and tooling in place to do the rebuild.
     
  5. spaceballs

    spaceballs Member

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    How about rebuild with 1/2 the cells (weight savings but less range and cheaper) for same overall discharge rate, and have the fastest roadster ever!
     
  6. slcasner

    slcasner Member

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    How would you modify the firmware to correctly charge and monitor the new pack?
     
  7. ElectricLove

    ElectricLove Member

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    Of course, the reality is that we would be building a custom pack, built to your specs if you so choose to be part of that process! We could use cells capable of higher output but half the capacity and therefore decrease your weight but maintain your overall power output! If you want less cells overall it would definitely result in CHEAPER...

    That will be totally up to the customer!
     
  8. ElectricLove

    ElectricLove Member

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    Since the firmware calculates the capacity based on how much charge the batteries take before reaching peak voltage levels (the actual "end point" setting of the BMS) I don't think this would actually be necessary to reprogram, the CAC should be recalculated by the vehicle after a few full charge/discharge cycles.

    The charge parameters of the new pack would be the same, the charger output would be the same as it is currently set for, the battery pack configuration would be the same, the only difference would be the actual cells, they would be new LG HG2 cells rather than "old" Panasonic B cells... Based on the fact that the Tesla Roadster firmware uses the current CAC to calculate the ideal range and the predicted range all of these numbers would also automatically adjust according to the new CAC (capacity), as best I can tell this would all work perfectly!

    Of course, this all comes with the understanding that this hasn't actually been done before, it is theoretical but is relatively sound theory...
     
  9. ElectricLove

    ElectricLove Member

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    #9 ElectricLove, Sep 24, 2015
    Last edited: Sep 24, 2015


    I will make some phone calls and see if we can get Tesla to agree to that but I think we all know that Tesla is very difficult to work with on stuff like that, there is a slim-to-none chance they will be "game" for that option, and you are right they may blame the pack, if they know it's been modified, I think it is inherent that any warranty from Tesla would be voided, they are going to wiggle like crazy to make sure they don't have to replace anything and it is reasonable that a warranty would be void if 3rd party modifications are made. However, I don't see a conceivable reason they wouldn't replace the PEM under their "out of warranty" program. If you are still under warranty, I would also be hesitant to make this move! But like I said, I will see if we can become an "authorized" provider... Maybe they'll be more flexible than traditionally since it is an opportunity to provide their 1.5 owners with something they aren't doing internally...



    EDIT: I forgot to mention, we also anticipate taking on repairing PEM in the future as well, if your PEM failed outside of warranty we may be an option for you on that repair as well!  The likely fail points are capacitors and IGBTs, both of which we have much experience with diagnosing and replacing in 3ph power systems...
     
  10. smorgasbord

    smorgasbord Active Member

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    Read this over at Edmunds.com:

     
  11. dhrivnak

    dhrivnak Active Member

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    While I am not in a position to be first I would strongly consider a 3rd party solution. That said could the firmware present any issues as I there are likely parameters set for the voltage cut offs.
     
  12. jordanthompson

    jordanthompson 2010 2.0 Sport, VIN 0683

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    I guess I'll ask the obvious (to me) questions:
    1) Why would I buy a 75kwh pack from a third party when I can get a slightly smaller one for the same price from the manufacturer? It would have to be significantly cheaper (IMHO) to get people to look at it.
    2) Will it be certified by the NTSB (which I am guessing the Tesla pack will)?
    3) I would be more interested in a smaller (lighter) pack with the same or even slightly less range as the original to improve(!) acceleration
     
  13. Habious

    Habious Member

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    I think the biggest concern isn't denial of warranty service; it's flat-out denial of service - "You've modified the car from the original specifications and, as such, we refuse to work on it until the unauthorized modifications are removed".

    They CAN do this (I've had this issue with my own dealership before (for a Lexus)).

    But, the issue with Tesla is, if they turn you away, you have nowhere else to go. You end up with a 125 MPH paperweight.
     
  14. ecarfan

    ecarfan Well-Known Member

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    Agreed, that is a serious concern. While I applaud someone stepping up with an aftermarket 1.5 battery, there is clearly a risk for anyone who installs such a battery on their Roadster UNLESS Tesla approves it. And I would be very surprised if Tesla did that. Please prove me wrong...
     
  15. dhrivnak

    dhrivnak Active Member

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    It should work in a 1.5 Roadster which Tesla said they will not build.
     
  16. TOBASH

    TOBASH Member

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    Don't you own an auto salvage Roadster you can experiment on?

    Why do you need someone else' car when you have one?

    You must certainly realize that once Tesla sees non-factory repairs and changes on the donor car, they will refuse to support that car in any way in the future. That makes YOUR salvage car the logical choice.

    Just MHO

    Best,

    T
     
  17. smac

    smac Active Member

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    Good luck with the enterprise, I'm interested to see where this goes.

    Having options for maintenance/repairs outside "main dealers" for all EVs is an interesting topic in general, and an area I'm sure we will see start to blossom over the next few years!
     
  18. ElectricLove

    ElectricLove Member

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    Sensible point, I sold my Roadster about a month ago, I no longer have it, additionally it did not need new batteries and it was a 2.0, not a 1.5... For those 3 reasons (and namely/especially the fact its now in SF-area with a new owner!) I am seeking another candidate.

    Someone with a salvage Roadster would be a fantastic candidate!

    We won't be modifying the structure of the pack whatsoever, only changing the batteries, it would be likened to changing the 12V battery on an ICE vehicle, I don't think it would legally void anything, but we all know Tesla doesn't play nice on those things...
     
  19. tvuolo

    tvuolo Member

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    I fully support your effort. I'd love to see a 3rd party option for Roadster repairs. I'm not in the market for a new battery at the moment, but knowing I'd have that option would be a huge comfort.

    I'd also be in the camp of wanting a similar range but lighter battery replacement.
     
  20. tom66

    tom66 Member

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    I would be willing to bet some bucks that Tesla also do "coulomb counting" to protect them against charging a damaged battery which may appear to continue charging at the peak voltage but in fact have significant internal leakage. So I would expect the car to cut off not much further than 10% over the rated kWh (or Ah capacity in this sense), perhaps even logging an error. Hence why Tesla need to update PEM firmware with the 3.0 upgrade.
     

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