Battery Module Load Test Methods?

Discussion in 'Gen 3 Prius Main Forum' started by Dave1UK, Jul 3, 2026 at 11:03 AM.

  1. Dave1UK

    Dave1UK Junior Member

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    So I have a previous post about getting the "Check Hybrid System Battery Stop In A Safe Place" message.

    I haven't taken the battery out yet. I'm wondering if I can run some useful tests before doing so to isolate which modules are actually the weakest/problem ones whilst monitoring them. By resetting the codes and driving with the Dr. Prius App - in live monitoring recording mode? To see how the modules behave whilst being charged/discharged?

    Basically an alternative to what would be done with individual modules by charging/discharging them using a nimh battery charger or other units/systems which I don't have access to.

    Any ideas on how to figure out a decent method? Charge the battery up whilst driving as fully as possible and then stay in EV mode to drain it whilst staying just below the middle mark where the engine would engage?

    It also seems weird that this issue occurred as my MPG has literally stayed the same averaging 55MPG. You always see people posting that their MPG is really bad like in the 40s.
     
  2. bisco

    bisco cookie crumbler

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    you can use dr. prius to load test the battery whilst driving:996946849
     
  3. Brian1954

    Brian1954 Senior Member

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    In your previous thread,
    https://priuschat.com/index.php?posts/3617720, you showed a P0A80 trouble code. Use a scanner that is capable of reading the freeze frame data for the P0A80 code. The freeze frame will tell you the voltages of the 14 battery blocks when the code was triggered. You can look at those voltages and determine where the bad battery block is located.