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Can I save my battery?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by James2, Apr 9, 2017.

  1. James2

    James2 Junior Member

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    Hi Prius Folk,

    I'm the original owner of a 2004 with ~120k (I don't remember exactly). The HV battery failed approx 2 years ago and has sat since then. I took out the battery and tested each cell about a month or two ago. Here's what it looks like (I'll upload a photo), and I'll list the voltages here:

    7.20
    7.40
    7.39
    7.36
    7.35
    7.34
    7.29
    7.30
    7.29
    7.28
    7.21
    7.26
    7.21
    7.21
    7.17
    7.14
    7.18
    7.14
    7.09
    7.17
    7.06
    7.13
    2.13*
    2.07*
    0.72*
    1.44*
    1.99*
    39.6mv*

    I'm wondering if this battery can be salvaged and rebalanced by replacing the 6 last modules. It's funny they all failed on one end of the pack and the cells are stronger on one side and get progressively weaker.

    Im thinking about getting a DC6 charger and 6 modules, and rebuilding the pack. Want to do it on minimal budget since this is a spare car and I have another that I drive to work everyday. I can take my time to work on it (obviously since it sat for 2 years).

    One more thing... we bought another 2015 Prius V which will have about 80k miles by the time we hit the 2 year mark in July of this year. Does the battery in that car need "maintenance" to extend its useful life? If so, and a grid charger can be used on both of our Prii- then I wouldn't be opposed to springing for the couple hundred bucks for a grid charger.

    So- can my battery be saved?
    And - can a grid charger be used on my 2004 AND 2015?
    And - does my 2015 need battery maintenance?

    Thanks in advance!
     

    Attached Files:

    #1 James2, Apr 9, 2017
  2. JC91006

    JC91006 Senior Member

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    You need to first charge the entire pack with a grid charger and then let it sit for a week. Then test the modules, after a week of sitting, the bad ones will be obvious.

    You can't tell by looking at them now. They are all out of balance
     
    #2 JC91006, Apr 9, 2017
  3. ericbecky

    ericbecky Hybrid Battery Hero

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    I would individually bring the lower ones up a bit closer before doing full pack charge/discharge sessions.

    I would recommend maintenance charging after a few years. Better to do it before the battery goes bad.
    Yes you can get a charger that works for both. But you will need to purchase two harnesses. One for each car. The harnesses are permanently mounted in each car.
     
    #3 ericbecky, Apr 9, 2017
  4. James2

    James2 Junior Member

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    Thanks for the replies. Sounds like the really low ones *may* not be the bad ones - and I'd have to charge them first to even tell which are really the bad ones. Which means I need a DC6 charger at least, even if I do decide to go with a grid charger. I'll take a look around to see what I can find for an individual module charger...
     
    #4 James2, Apr 9, 2017
  5. James2

    James2 Junior Member

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    Can't seem to find a supermate DC6 in stock - what are people using these days for an individual module charger? Amazon has one, but it is quoting 4-6 week delivery, presumably from China.
     
    #5 James2, Apr 9, 2017
  6. ericbecky

    ericbecky Hybrid Battery Hero

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    You do not have to charge the low ones before charging g the while pack. It was just a suggestion. A whole pack charger should go slow enough to burn the excess charge as heat.

    So if you don't want to wait, why not just build, or buy, a whole park charger now.

    That should tide you over until you get your single module charger.
     
    #6 ericbecky, Apr 9, 2017
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