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Battery upgrade

BrachaBracha Member Posts: 33
in Battery/Electrical & Solar
This power and battery choices challenge me.  Right now, I have a group 31 and group 24 AGM deep cycle batteries.  If I swap to lithium, do I replace both with a lithium 12v 100ah?
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  • BrachaBracha Member Posts: 33
    Just purchased 2 100ah renogy smart lifepo4 batterries to replace my two previous.  
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  • AnOldURAnOldUR Member Posts: 1,387
    You can't have an AGM and a lithium in parallel because they have different charging profiles. I'd suggest doing as @Bracha did and replacing both of your AGM's with two new identical 100Ah LiFePO4's.
    Stockton, New Jersey
    2020 nuCamp T@B 320S * Jeep Wrangler

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  • pthomas745pthomas745 Moderator Posts: 3,956
    What year is the trailer?  If you have installed solar and the Victron controller, you need to set up the App for the proper lithium charging profile.

    2017 Outback
    Towed by 2014 Touareg TDi
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  • SLJSLJ Member Posts: 541
    Knowing your year and model would help.  I would never mix types of batteries, manufacturers, or models. Switch to a lithium LiFePO4 battery and update the settings in your solar controller. If you use it or have it charging below freezing when stored make sure the LiFePO4 battery you get has low temp charging shut off.
    2021 T@B 320 S Boondock
    2023 Ford Maverick XLT
    The Finger Lakes of New York
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  • HoriganHorigan Member Posts: 673
    Bracha said:
    Just purchased 2 100ah renogy smart lifepo4 batterries to replace my two previous.  
    Good choice!  Now the fun begins on updating the charging profile on your solar controller (if installed) and deciding on whether or not to upgrade your converter to fully charge your new batteries. (I elected not to and just rely on my solar to top up the batteries.)
    Rich
    2019 T@b 400
    2013 Toyota Highlander 3.5L V6
    Bellingham WA
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  • jmcgonigjmcgonig Member Posts: 12
    The "best" solution is always to upgrade the batteries at the same time (same manuf/type).  You never want to mismatch AGM/Lithium.  You also want your converter to be in lithium mode - i know people here don't, but its not good for the batteries.  Also have to update your solar MPPT to the right profile.
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  • BrachaBracha Member Posts: 33
    Not mixing.  Replacing both with Lithium.  I have a 2022 T@b 320s.  To get round any converter charging issue.  I have a Victron p22 charger.....
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  • AnOldURAnOldUR Member Posts: 1,387
    jmcgonig said:
    ...  You also want your converter to be in lithium mode - i know people here don't, but its not good for the batteries ...
    What I've read says that lithium will last longer when not constantly charged to 100%. When parked at home, I plug into shore power and turn solar charging off to let our LiFePO4's hold the +/- 80% that we get from the non-lithium converter. Once on the road, solar will normally top off batteries for the trip ahead. If it looks like there will be several days of poor sun, I'll use a NOCO to top off before leaving or when shore power is available.

    Someone more knowledgeable than me please let me know if this is flawed thinking.

    Stockton, New Jersey
    2020 nuCamp T@B 320S * Jeep Wrangler

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  • HoriganHorigan Member Posts: 673
    Sounds like a good plan. 
    Rich
    2019 T@b 400
    2013 Toyota Highlander 3.5L V6
    Bellingham WA
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  • elbolilloelbolillo Member Posts: 381
    AnOldUR said:
    jmcgonig said:
    ...  You also want your converter to be in lithium mode - i know people here don't, but its not good for the batteries ...
    What I've read says that lithium will last longer when not constantly charged to 100%. When parked at home, I plug into shore power and turn solar charging off to let our LiFePO4's hold the +/- 80% that we get from the non-lithium converter. Once on the road, solar will normally top off batteries for the trip ahead. If it looks like there will be several days of poor sun, I'll use a NOCO to top off before leaving or when shore power is available.

    Someone more knowledgeable than me please let me know if this is flawed thinking.

    My understanding is that LiFePo4 batteries are generally more forgiving compared to other battery types when it come to charging. In theory, yes, it might last minimally longer if not constantly charged to 100%. I just try to get mine topped off at home before any trip and during the trip try to keep it as fully charged as I am able using solar.
    _____________________________________________________
    Ken / 2023 Tab 400 “La Bolita” (23,000+ miles) / 2024 Toyota Sequoia
    2024 - 3 Trips - 35 nights - 9 National Parks, 3 National Forests
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  • AnOldURAnOldUR Member Posts: 1,387
    edited May 2023
    I agree @elbolillo. The difference is probably minimal. My post was more about @jmcgonig 's remark that using a non-lithium converter could damage a lithium battery. I don't believe that is correct.

    jmcgonig said:
    You also want your converter to be in lithium mode - i know people here don't, but its not good for the batteries.

    Stockton, New Jersey
    2020 nuCamp T@B 320S * Jeep Wrangler

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  • BrachaBracha Member Posts: 33
    AnOldUR said:
    You can't have an AGM and a lithium in parallel because they have different charging profiles. I'd suggest doing as @Bracha did and replacing both of your AGM's with two new identical 100Ah LiFePO4's.
    I should have been more clear.  I was wondering should I replace the batteries 1:1 or 2:1 (one being a 200ah lithium.
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  • BrachaBracha Member Posts: 33
    elbolillo said:
    AnOldUR said:
    jmcgonig said:
    ...  You also want your converter to be in lithium mode - i know people here don't, but its not good for the batteries ...
    What I've read says that lithium will last longer when not constantly charged to 100%. When parked at home, I plug into shore power and turn solar charging off to let our LiFePO4's hold the +/- 80% that we get from the non-lithium converter. Once on the road, solar will normally top off batteries for the trip ahead. If it looks like there will be several days of poor sun, I'll use a NOCO to top off before leaving or when shore power is available.

    Someone more knowledgeable than me please let me know if this is flawed thinking.

    My understanding is that LiFePo4 batteries are generally more forgiving compared to other battery types when it come to charging. In theory, yes, it might last minimally longer if not constantly charged to 100%. I just try to get mine topped off at home before any trip and during the trip try to keep it as fully charged as I am able using solar.

    elbolillo said:
    AnOldUR said:
    jmcgonig said:
    ...  You also want your converter to be in lithium mode - i know people here don't, but its not good for the batteries ...
    What I've read says that lithium will last longer when not constantly charged to 100%. When parked at home, I plug into shore power and turn solar charging off to let our LiFePO4's hold the +/- 80% that we get from the non-lithium converter. Once on the road, solar will normally top off batteries for the trip ahead. If it looks like there will be several days of poor sun, I'll use a NOCO to top off before leaving or when shore power is available.

    Someone more knowledgeable than me please let me know if this is flawed thinking.

    My understanding is that LiFePo4 batteries are generally more forgiving compared to other battery types when it come to charging. In theory, yes, it might last minimally longer if not constantly charged to 100%. I just try to get mine topped off at home before any trip and during the trip try to keep it as fully charged as I am able using solar.
    I was reading that LiFePO4 can be discharged to zero and brought back AND it is better if they are kept at 80 %.  So I agree with several comments.  This makes them Much more forgiving AND they last twice as long!
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  • pthomas745pthomas745 Moderator Posts: 3,956
    @Bracha "discharged to zero" is certainly a nice thing, but in some cases, the lithium battery monitoring system will shut down the battery until it can be jump started.  We may have already seen issues like this with the new battery setups in the 2023's.  At least, we have seen some blown fuses and tripped Gloso breakers in the newer NuCamp installed multiple lithium battery setups.  This is the same sort of thing that happened with the 400 with the large dual 6V installs: a depleted battery, a surge of charging power, and...there goes your 30 amp fuses at the battery.  The Gloso had to be added to the first few 400 builds because of this.
    A Battleborn BMS will shut down the battery if it reaches a certain low discharge.
    Find the section on "low voltage disconnect" on their FAQ page.

    2017 Outback
    Towed by 2014 Touareg TDi
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  • jmcgonigjmcgonig Member Posts: 12
    AnOldUR said:
    I agree @elbolillo. The difference is probably minimal. My post was more about @jmcgonig 's remark that using a non-lithium converter could damage a lithium battery. I don't believe that is correct.

    jmcgonig said:
    You also want your converter to be in lithium mode - i know people here don't, but its not good for the batteries.

    I didn't say "damage".  I said not as good.  There is a difference.  I think the lifespan of a lithium battery is maximized when charged with the right profile.
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  • HoriganHorigan Member Posts: 673
    Bracha said:
    AnOldUR said:
    You can't have an AGM and a lithium in parallel because they have different charging profiles. I'd suggest doing as @Bracha did and replacing both of your AGM's with two new identical 100Ah LiFePO4's.
    I should have been more clear.  I was wondering should I replace the batteries 1:1 or 2:1 (one being a 200ah lithium.
    It doesn't really matter.  It's mainly driven by the space available for the battery(ies).  200aH batteries tend to be taller.
    Rich
    2019 T@b 400
    2013 Toyota Highlander 3.5L V6
    Bellingham WA
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