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Has anyone tried replacing the 12 volt battery with a LiFePO4 12.8 V battery?

Discussion in 'Gen 4 Prius Technical Discussion' started by GoodOldBob, Dec 1, 2023.

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  1. RandyPete

    RandyPete Member

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    What I am trying to say is that "12.2 volts" is not a battery SOC. It is a bettery voltage.
     
    #21 RandyPete, Mar 24, 2024
  2. vvillovv

    vvillovv Senior Member

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    So basically your nit pickin my use of SOC. You wanna be the first to take a set of Amp reading while 12 volt charging is happening by the Gen 4 and or 5 Prii, so we all can hone in the real 12 volt battery SOC, and I'll promise to never use SOC in a description of only the voltage reading again. Great job.
     
    #22 vvillovv, Mar 24, 2024
    Last edited: Mar 24, 2024
  3. sylvaing

    sylvaing Senior Member

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    The 13.5 volt is pretty consistent, yes. As can be seen here when the battery was warming up

    Screenshot_20240324-200804.png
    And when preheating (or A/C) was turned on (that 13.5V before the drive was 10 minutes long)
    Screenshot_20240324-200734.png

    But when charging, the voltage does fluctuate, as can be seen below. It fluctuates around 12.8V.

    Screenshot_20240324-200646.png
     
    #23 sylvaing, Mar 24, 2024
    RandyPete and vvillovv like this.
  4. GoodOldBob

    GoodOldBob Junior Member

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    An interesting article on Battery University website looks at Lithium Ion batteries. Noting that the duty cycle of 100% charge/discharge is only 300 cycles. Yet, a Prius manages to last 10 years....how do they do it? Seems that if you only partially charge and discharge the Traction Battery, the lifespan is greatly prolonged: up to 18,000 cycles if you only charge to 65% and discharge to 55%....which is why Toyota can confidently warranty a 10 year lifespan on the Traction battery.
     
    #24 GoodOldBob, Jun 11, 2024
  5. sylvaing

    sylvaing Senior Member

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    It's probably like the Prime. The 100% of the traction battery for EV is actually from 15% to 85% of the traction battery. At 8.8kWh, that's 6.1kWh. Below 15% is reserved for the hybrid mode. Above 85% isn't used to, like you said, prevent battery degradation.
     
    #25 sylvaing, Jun 11, 2024
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  6. GoodOldBob

    GoodOldBob Junior Member

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    Even Android cell phones have caught on:

    upload_2024-6-11_20-5-25.png
     
    #26 GoodOldBob, Jun 11, 2024
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