Help! Battery losing charge!

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by PriusHead05, Oct 26, 2020.

  1. PriusHead05

    PriusHead05 Member

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    I wanted to readjust my Prius in the driveway. I turned the car on. It had 4 bars on the SOC. I put it in reverse, dropped in the red zone to two bars. The ICE turned on to charge the battery. While reversing, the SOC dropped to one bar even though the ICE is charging the battery. This has happened a few times. What is the problem. Thanks!

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    #1 PriusHead05, Oct 26, 2020
  2. PriusHead05

    PriusHead05 Member

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    #2 PriusHead05, Oct 26, 2020
  3. PriusHead05

    PriusHead05 Member

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    When I started my Prius, the SOC was at 4 bars. I put the car in reverse and it dropped to two bars. Even though the ICE is on and charging the battery, the SOC is now at 1 bar. This has happened a few times and I am worried about it since I wasn't in reverse but less than a minute. Please help! It's a 2005 with 138,000 miles.

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    #3 PriusHead05, Oct 26, 2020
  4. davecook89t

    davecook89t Senior Member

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    The ICE cannot charge the HV battery in either Reverse or Neutral. For that reason, you should avoid leaving the shift lever in either of those positions for a long period of time. The SOC dropping to one bar should not, in itself, be a problem, but if you see it regularly dropping to that level and then quickly going up to 6 or 7 bars as you are driving, that is an indication that your HV battery is getting weak.
     
    #4 davecook89t, Oct 26, 2020
    SFO likes this.
  5. PriusCamper

    PriusCamper Senior Member

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    Your battery needs reconditioning... It's still healthy but operating at 50% capacity and needs to be restored to 96% via Prolong Battery Systems | Hybrid Automotive California, USA and here's more info about the science of that here: BU-807: How to Restore Nickel-based Batteries – Battery University

    There's cheaper ways to recondition if you want to DIY it, but take a long time...
     
    #5 PriusCamper, Oct 26, 2020
  6. JC91006

    JC91006 Senior Member

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    this symptom means you have weak hv battery. Next time you can start the car, wait until the car warms and engine stops and goes into hybrid mode. Then drive off. This usually will keep the HV battery from immediately dropping charge on the SOC
     
    #6 JC91006, Oct 26, 2020
    SFO, Raytheeagle and Aaron Vitolins like this.
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