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How could I get a 10 KWh battery pack using Model S cells?

Discussion in 'Off Topic' started by Raffy.Roma, Mar 23, 2014.

  1. Raffy.Roma

    Raffy.Roma Active Member

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    I am planning to convert to electric my old car (1999) and I was thinking that for the EV range that I wish I would need a 10 KWh battery pack. If I would like to use the light cells of the Model S how can I get such a 10 KWh battery pack?

    Hints and advices on this matter are welcome.
     
  2. techmaven

    techmaven Active Member

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    There is a lot more to Tesla's battery pack than the cells. Matter of fact, it may be relatively dangerous to use cells similar to Tesla's cells in a vehicle without taking the steps Tesla took to make the battery pack safer. Unless you are using a Model S battery pack with a functioning cooling loop, you are probably asking for more trouble than its worth. I think some people will have success basically rebuilding a crashed Model S, but just using the cells is unlikely to work well.

    Instead, you might want to get a variant of LiFePO4 cells, most likely in pouch format. You can readily buy these from a number of suppliers both as individual new cells as well as in battery packs. You might find battery sub-packs from a crashed Nissan Leaf or other production EV car. For example, you can get the bricks of cells that are inside a Nissan Leaf battery pack. These are not liquid cooled, so it's easier to deal with and are far less likely to have a fire event. Correspondingly, they have far lower specific energy and volumetric energy. Brand new and in single car volume, it would likely cost somewhere around $500-600/kWh to source new LiFePO4 cells (A123 for example) here in the U.S. which ultimately come from Asian suppliers.

    Further, you are likely to find electronics that can deal with battery management with LiFePO4 far more readily than Telsa's cells.

    I was seriously considering buying flooded Nissan Leaf's that are total write-offs (not even salvage title due to flood) just for the high voltage battery for solar storage. Extract the battery bricks and sell the rest off.
     
  3. Raffy.Roma

    Raffy.Roma Active Member

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    @techmaven

    Thank you for your advice. Can you give me some links about battery packs consisting of LiFePO4 cells that could fit to my case?
     
  4. techmaven

    techmaven Active Member

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    I am still early in my research and most of my interest lies in solar storage at the moment rather than EV conversion. Many of the parts and pieces are very similar, however. After searching for a while at solar oriented parts, I began looking at using EV parts and possibly crashed EVs as a good starting point.

    In any case, you can look at:

    LiFePO4 Batteries


    to get an idea. I started sifting through Alibaba for Chinese suppliers also and there are many possibilities, but I have no experience with any of them.

    There are a number of people that build their own battery packs from cells. I found their construction techniques to be quite suspect, especially in a situation where I might be strapped into a vehicle that can burn.

    This video, for example, shows the construction of an A123 module for EVs you would actually want:

    A123 Systems Li-ion battery technology - YouTube

    There are a number of places and videos that can provide the A123 cells (or similar) all over the internet, but EV specific modules is much harder.

    NEW 11kW/h Battery Block 182V /60Ah

    Leaf's battery packs are technically lithium manganese but between Nissan/Renault and the LG Chem cells made for the Chevy Volt/Ford Focus EV, there may not be a readily available module made for EV situations available. Most of the rest are motorcycle or scooter batteries and in some cases, solar storage.
     
  5. Raffy.Roma

    Raffy.Roma Active Member

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    Thank you very much techmaven. I think that the last link you gave me could fit perfectly to my case. :cool:
     
  6. muleferg

    muleferg Member

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  7. Dwdnjck

    Dwdnjck Member

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    Check out EV WEST. They offer Tesla "style" sub packs at 3 kWh each. Around $900 per unit.
     
  8. wycolo

    wycolo Active Member

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    Check out the VW Bus on YouTube. An air-cooled battery pack using 18650s. More fun than should be allowed!!
    --
     
  9. Saghost

    Saghost Active Member

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    What output voltage do you need?

    Unless I'm missing something, two standard 85 kWh battery pack modules (out of the sixteen in the pack) will make a just over 10 kWh, 48 V nominal pack.

    You'd have to reconnect the cooling, and do some creative bits with the BMS, but the physical pack is easy.
    Walter
     

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