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HV battery sudden discharge

Discussion in 'Gen 2 Prius Technical Discussion' started by Siber Pir8, Aug 18, 2020.

  1. Siber Pir8

    Siber Pir8 Junior Member

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    Hi all,

    I have replaced 5 cells last week and balanced the battery correctly.. The battery has been great getting 56mpg over 300miles
    What i had this morning was, while i was driving at 40mph steady, the cars engine stuttered for a second then over the space of about 20 seconds the hv battery started to discharge over 10 seconds from 2 bars from the top all the way down to 1 purple bar.. Then it started to charge again.
    The battery has been holding at 5 bars over the space around 300 miles.
    There are no fault codes that occur during this time.
    Has anyone had this symptom?
     
    #1 Siber Pir8, Aug 18, 2020
  2. edthefox5

    edthefox5 Senior Member

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    Replacing your original cells with same vintage cells which just happened to not have failed again is no guarantee of anything except you will have to go back into the pack and service it again.

    And you u have still many original 14 YEAR OLD Modulles.

    Did you check all the ecu plugs for corroded pins did you take the cover off the ecu to check the circuit board for corrosion? Are all the jumper plates clean as can be are all the thermal sensor wires free of corrosion
    And everything torqued down correcty?
     
    #2 edthefox5, Aug 18, 2020
  3. davecook89t

    davecook89t Senior Member

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    Your HV battery may very well be weak, but I don't think that would account for the behaviour you saw on the MFD over the space of a few seconds. I would guess your engine completely died and the car could only maintain its speed by relying completely on the HV battery. No stored codes and no check engine light either when this happened? How long has it been since you have changed the spark plugs? You may have another problem with your HV battery down the road, but more immediately I think you would want to focus your attention on the fuel and air delivery and ignition systems of your ICE.
     
    #3 davecook89t, Aug 18, 2020
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