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  • 1.  Battery Charging Best Practice

    Silver
    Contributor
    Posted 01-11-2023 03:34 PM
    Edited by Ella Nielsen 01-11-2023 03:34 PM
    Hi all,

    I had someone ask me the following question below; I'm hoping you all can assist me in getting an answer for them. Thank you in advance!

    "I have a SolarEdge home solar PV system with LG Chem battery backup.
    A couple of years ago I purchased and Electric Vehicle and as part of my EV education learned the do's and don'ts of lithium ion battery charging best practices. A major "don't" that I learned was the long term detrimental effects of regularly charging the battery to 100% and then not immediately using that stored energy for  the vehicle's consumption needs.  The EV mantra is, charge to 80% maximum on a daily basis unless you are going on a long trip and will be using that full charge right away.

    After learning about this practice for my EV, I started wondering about the long term effects of 100% daily charging of my PV battery, After doing some more research I found a paper published by Battery University (BU-808: How to Prolong Lithium-based Batteries) that shows the long term detrimental effects of  repeated 100% maximum SOC on battery life expectancy.   I subsequently  made the decision to reset the maximum SOC of my battery to 80%.
    My Question Is: Why is this not a topic of research/discussion in the Solar PV industry/media?  It is certainly possible that it is being discussed somewhere and I am ignorant of this fact? Please educate me."

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    Ella Nielsen
    Membership & Engagement Manager
    American Solar Energy Society
    Boulder CO
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  • 2.  RE: Battery Charging Best Practice

    ASES Life Member
    Posted 01-16-2023 10:52 AM
    Edited by Mike Curran 01-16-2023 11:28 AM
    This question comes up occasionally on the Outback Power user forum. This thread (4th post down) has a response I got from my battery supplier, Simpliphi, a leading LiFePO4 battery manufacturer: https://forum.outbackpower.com/viewtopic.php?t=17853
    I have been operating my battery at 99-100% SOC since installing them in 2019. As the thread states (perhaps) only time will tell.
    Edit: Note there is a big difference in the battery chemistry of EVs and stationary storage for residential use. EV batteries use cobalt in them whereas home storage batteries do not. May or may not be relevant.

    Mike Curran
    Retired EE


  • 3.  RE: Battery Charging Best Practice

    Silver
    Contributor
    Posted 01-16-2023 07:26 PM
    Thank you so much, Mike! This is incredibly helpful, I really appreciate your response.

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    Ella Nielsen
    Membership & Engagement Manager
    American Solar Energy Society
    Boulder CO
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