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Is the a good thread on Battery Health?

Discussion in 'Gen 2 Prius Technical Discussion' started by Chuck., Feb 10, 2016.

  1. Chuck.

    Chuck. Former Honda Enzyte Driver

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    Good fuel economy is much easier to understand than health of the battery pack.

    Again, is there a good reference thread on taking care of the battery pack?

    This is what I understand - by all means add and correct.
    • Don't let your car stay idle for more than a few days. Batteries lose about 1% daily.
    • A state of charge (SoC) between 60% to 30% is best. This is because extreme charging or discharging causes physical reactions in the batteries - wear-and-tear.
    • Heat is your enemy. That's why overcharging is bad. When possible, don't park in the Sun - park in a cool place instead. Make sure the vents in the back seat are not blocked.
    • Avoid the tempetation to "top off" the battery pack. Conversely, don't do extended EV modes.
    • A grid charger could extend the life of the pack, but check for feedback before buying.
     
    #1 Chuck., Feb 10, 2016
  2. jeff652

    jeff652 Senior Member

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    I agree with most of this, and would add a few comments:
    • Don't let your car stay idle for more than a few days. Batteries lose about 1% daily.
    Each cell discharges at different rates within a pack. The car has no concept of time passage when parked and will think the SOC% has not changed since the ignition was turned off. Driving on a discharged unbalanced pack is very hard on the cells and will accelerate battery failure. Anytime the car sits for more than a week unused, the battery should be charged to re-balance the cells before starting the car.
    • A state of charge (SoC) between 60% to 30% is best. This is because extreme charging or discharging causes physical reactions in the batteries - wear-and-tear.
    The shallower the cycling of the pack during normal use, the longer the pack is likely to last. This is likely why the Toyota packs in general tend to last longer than the Honda packs. This is less applicable when reconditioning the pack due to the very low current levels being used.
    • Heat is your enemy. That's why overcharging is bad. When possible, don't park in the Sun - park in a cool place instead. Make sure the vents in the back seat are not blocked.
    Agreed 100%. This is also why it's so important to inspect/clean the HV battery fan once every 50k miles (or more).
    • A grid charger could extend the life of the pack, but check for feedback before buying.
    Our prolong Battery Systems are proven to extend the life of the battery. Charging along is not a solution, reconditioning of the pack most be regularly performed. There are independent tests on this forum and before/after comparisons on our website. We have sold over 1,600 of them with extremely high success rates. interested parties can read reviews from past customers on our Facebook page or eBay feedback profile:
    Facebook - Hybrid Automotive LLC
    eBay Feedback Profile for HybridAutomotive
     
    #2 jeff652, Feb 10, 2016
  3. bisco

    bisco cookie crumbler

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    letting your car sit idle doesn't significantly affect the hybrid battery. the 12v is a different story.

    you have no control over charging and discharging. ignore it, that's what computers are for.

    heat is your enemy, agree with not parking in the sun and use sunshades.

    you can't top off the battery pack, just drive it.

    i'll let jeff speak to the grid charger.:p
     
    #3 bisco, Feb 10, 2016
  4. Chuck.

    Chuck. Former Honda Enzyte Driver

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    Got a question: If you leave your headlights on and the 12v battery goes dead, does it also degrade the traction pack?

    Yes, I just did that. :oops:
     
    #4 Chuck., Feb 18, 2016
  5. jdenenberg

    jdenenberg EE Professor

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    No, but you have shortened (perhaps ended) the life of the 12v battery as well as putting the power electronics at risk (take great care not to reverse the polarity) when you jump the 12v battery to get going.

    JeffD
     
    #5 jdenenberg, Feb 18, 2016
  6. Chuck.

    Chuck. Former Honda Enzyte Driver

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    ^ thank you for your prompt reply. :)

    With the early Honda Insights, a dead 12v could degrade the battery pack.
     
    #6 Chuck., Feb 18, 2016
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    Our car was manufactured Aug 09 and we bought it new in Nov 10. 12 volt was a goner but the hybrid battery was fine.
     
    #7 Mendel Leisk, Feb 18, 2016
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