Does heat make the hybrid battery deplete when not used?

Discussion in 'Gen 2 Prius Main Forum' started by Prius92, Sep 15, 2025 at 7:30 PM.

  1. Prius92

    Prius92 Active Member

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    Drove 75 miles Saturday, parked and battery was 2 bars away from green.

    Did not drive my car yesterday, was 95 outside.

    Got it in today and the battery was so drained it moved like a snail until it charged up. Drove just fine after that.

    Did a health check and all that with Dr. Prius. No issues.
     
  2. bisco

    bisco cookie crumbler

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    yes, especially an old battery was it parked in the sun?
     
  3. PriusCamper

    PriusCamper Senior Member

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    This is a known problem of old Prius, especially when pack gets old and looses capacity and needs deep cycling to restore capacity.

    Also corrosion builds up from the hybrid battery in the battery ECU and you may be able to eliminate this symptom by cleaning the pins where they solder to the board inside the battery ECU.
     
  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Time alone does a decent number on it. Heat hurts more in usage- but it's never good.