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PRIUS TRACTION BATTERY CODES or SERIAL #'s BY PRODUCTION YEAR?

Discussion in 'Gen 2 Prius Technical Discussion' started by jeg, Jan 30, 2010.

  1. jeg

    jeg Junior Member

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    2005 Prius
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    Thanks to all for providing any information that you maybe able to offer...

    I have a 2005 Prius that just turned 170k miles. Over the last year or so, my mileage has dropped from the mid to high 40's, down to consistently below 40 (high 30's).

    Just a couple of weeks ago, I replaced the auxiliary 12 volt battery with the Optima based on what some have experienced as positive benefits within this forum. I have not been as lucky.

    As a result, I believe that I need to begin looking for a good used replacement traction battery. With that said, does anyone know if there are codes or serial numbers that one can access in order to determine whether what you are about to buy is the production year (2008) that is advertised by the seller? In other words, I just want to make sure that if I am getting ready to buy an advertised 2008 Prius battery with low mileage, I just want to make sure (with the battery code / serial number) that it is not another 2004 or 2005 with high mileage.

    Any thoughts or comments would be greatly appreciated!
     
    #1 jeg, Jan 30, 2010
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    First, I can't help you with your question regarding date codes. I noticed serial numbers on the battery modules but not date codes.

    It sounds like your car does not have any logged DTC, and your motivation to replace the traction battery is simply based upon reduced mpg.

    If I am correct, then I would suggest that you first take care of the basics. Have you performed all scheduled maintenance, such as replacing the iridium spark plugs at 120K miles and making sure the engine air filter is clean?

    How about the other usual suspects, such as cleaning the MAF sensor, the throttle body interior and throttle plate, checking wheel alignment, parking brake drag, tire pressure, and ensuring the engine oil level is not overfilled and is the correct 5W-30 viscosity? At 170K miles, you might also have a cylinder leakdown test performed to see if your gasoline engine has any wear issues.

    After you've exhausted that list, if you still want to get a newer battery then go for it - however I am not convinced that will help your mpg, absent a DTC relating to the traction battery.
     
    #2 Patrick Wong, Jan 30, 2010
  3. dogfriend

    dogfriend Human - Animal Hybrid

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    Adding to Patrick's advice, if you want to verify the health of the HV battery in the absence of any DTCs, you could get someone with the proper scan tool (i.e. a Toyota dealer or well equipped independent) to scan the individual block voltages. If they are all within the allowable tolerance range then your battery is probably ok.
     
    #3 dogfriend, Jan 31, 2010
  4. Mike Dimmick

    Mike Dimmick Active Member

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    This article may be a good lead:

    Predictive battery failure analysis for the Prius Hybrid

    It's written for the Gen 1 Prius but the technique is much the same for Gen 2, it just has fewer modules (28 rather than 38, so 14 rather than 19 battery blocks).
     
    #4 Mike Dimmick, Jan 31, 2010
    1 person likes this.
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