Gen 3 Bottom Voltage Battery balance

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Austin Longenecker, May 18, 2020.

  1. Austin Longenecker

    Joined:
    Sep 24, 2018
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    Location:
    Austin Tx
    Vehicle:
    2010 Prius
    Model:
    N/A
    Howdy. I've recently been experiencing some issues with the amount of power output in my 2010 prius. I purchased an OBDii and ran the Dr. Prius battery test. The results say I have 2 modules with bottom voltage unbalanced. Everything else reads normal. Can I take it to a specialist to have the modules balanced, and if so, what can I expect that to cost? Would it be better to invest in a good replacement battery instead?

    The battery level does not drop noticable when parked for several days. The battery level will drop fast when accelerating up a hill after pulling out of my driveway but charges and discharges at a normal rate after that. Maybe only a bit faster than usual but not a sudden jump or drop.

    I've got 128K miles
    Brand new 12v
    Vehicle has had to deal with Texas heat for all 9 out of its 10 years.
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    best bet is a new oem battery, around 2k plus install.

    next is 'newpriusbatteries.com' aftermarket $1,600. plus install.

    after that, you can replace the bad cells, or replace them and rebalance, but both are iffy as to how long they'll last until another goes out of balance.

    since you battery is still working and no trouble codes, hybrid automotive has a charger balancer that may extend the life.

    i don't know any good shoppes in your area, but it's worth a call to matt at texas hybrids. he is a member here, gives good advice, and may know someone in your area. i think he does mobile installs, but i'm not sure how far he goes.

    unrelated, you should look into egr circuit cleaning (search here for threads) and oil catch can installation before you blow a head gasket.

    have you done the required 120k maintenance?
     
  3. Austin Longenecker

    Joined:
    Sep 24, 2018
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    Location:
    Austin Tx
    Vehicle:
    2010 Prius
    Model:
    N/A
    Thank you for your reply. I have done the 120K service and had the ERG system replaced last year. I've done the research on where to get a new battery and what cost, I just need to know whether or not its time to. The Texas Hybrids website doesn't seem to have the 3rd-gen battery available, only shows 2nd gen.

    I assume I can purchase an OCC and have a local mechanic install it for me? I do not have DIY equipment.

    If you, or anyone, has Minnesota recommendations, I am moving back there in a few weeks.
     
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