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battery heat exchanger

Discussion in 'Roadster: Technical' started by doug, Nov 11, 2009.

  1. doug

    doug Administrator / Head Moderator

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    Here's a press release from a company that apparently makes a heat exchanger for the battery in the Roadster 2.

    Dana Develops Industry-First Battery Cooling Technology for Electric Vehicles


     
  2. mpt

    mpt Electrics are back

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    It's a bit noisy, that's all I can say... if it's what I think it is anyway.

    When the battery gets warm there's a motor sound from the bulkhead in front of the passenger. It runs at variable speeds, in steps for a minute or so until the battery temperature is under control. At the same time, the cabin warms up!
     
  3. DrComputer

    DrComputer Member

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    That noise is from the A/C compressor. I doubt Dana had anything to do with that horrible selection since they just designed the battery heat exchanger. I agree, not only is the compressor noisy, it also vibrates horribly once it starts using 8+ amps. I've complained to Bob in the LA store about it but I just get the "that's the way it works" answer. Now that it's a bit colder here in LA, it doesn't come on as ofter so it's a bit more tolerable. In the summer it drove me crazy every time it would try to cool the battery pack and the cabin at the same time.
     
  4. chronopublish

    chronopublish 2008 Roadster #VP27

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    #4 chronopublish, Nov 12, 2009
    Last edited: Nov 12, 2009
    DrComputer--

    It's funny you mention that - I recently took delivery of my 2008 Roadster (formerly VP27) and the compressor noise bothered me so much that I was convinced something was wrong with the car, so I took the car to the LA store and Bob assured me that it was normal.

    He also mentioned that it only happens in 2008 cars, not in 2010s - I take from your post that is not actually the case.

    That noise is loud enough that I am surprised that I've never seen it mentioned in any review or any post in these forums until today!

    I have noticed that putting the car into Range mode reduces the likelihood of the compressor coming on, though it still will if it's hot enough. I've also observed that if the compressor is on and I switch into Range and then immediately back to Standard, it shuts off and usually stays off.

    I wish there were some way to override the compressor completely and just tell the car "never turn this on unless I'm traveling at freeway speeds". I would sacrifice any amount of battery life not to have to deal with that noise.
     
  5. DrComputer

    DrComputer Member

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    The compressor on the 2010 is actually louder than the 08 when it hits full speed. This was confirmed by Bob. So far they have no fix, nor do I think they ever will. Maybe in Roadster 3.0 they will get a manufacturer to make a quiet electric compressor. I know they exist as my Lexus LS600hL has an electric compressor that is very quiet (and actually produces very cold air--what a concept).
     
  6. TEG

    TEG TMC Moderator

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    Electric A/C compressor:
    3174844675_31022b0a8e.jpg
     
  7. moe1343

    moe1343 New Member

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    Battery peak tempreture

    Does anyone know how hot the battery gets without cooling?
    Thank you
    Moe
     
  8. DaveD

    DaveD EVs Kick Gas!

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    This implies a cooling system failure (or battery depletion) which is not normal, and definitely Not Good.
     
  9. moe1343

    moe1343 New Member

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    Sorry . My fault as I was not clear on my question. I didn't mean cooling failure circumstances . I meant if we want to use the battery heat to heat up the cabin in cold conditions what kind of temperature are we looking at? Say the battery tempreture rises to 90C and ambient temp is only 2C . We can use the temp difference to heat the cabin simultaneous with cooling the battery by air or coolant . Is the 90C with no cooling after steady state opertion is reached a right figure or is it too high?
     

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