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    LifePo4 Question

    I have a 206AH SOK 12v battery. Planning to add one or two more batteries with a Victron Multiplus install this spring. Also, have solar with the new RV so likely going to add one more panel for now and potentially change things out after a year if I feel like improving on the system will be useful after boondocking more this summer. Now to the question...

    I see there are more battery options these days that seem to have positive reviews (mainly Will Prowse), such as the Power Queen brand. Wondering how well it would work to add one or two 200AH 12v Power Queen batteries in parallel with my existing 206AH SOK? Reason being that the Power Queen is $650 and an SOK is $1030. So, for a bit more I could add two Power Queens vs one SOK and end up with 7.2kw total. It seems like matching the capacities as closely as possible would be a good thing, but not sure if other differences would be an issue?

    At the time, I bought the SOK because it was half the price of Battle Born for the same watt hours.
    Chad
    2023 23LDE 965W Solar, Victron Multiplus, Solar Controllers, Cerbo GX, 4x280AH DIY Lithium Batteries, SeeLevel Tank Monitoring, Shock Absorbers (Replaced 2022 22MLE)
    2022 F350 6.7L Superduty, Carbonized Gray, Ultimate Lariat Pkg, 4WD, Crew Cab, 160" Wheelbase, 3.55EL Rear End, 3566# Payload
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    Hi Riverbug,

    I think it is close enough in size to parallel then together. One thing I would recommend is to use a bus bar rather than cables to tie the batteries together. Got a good solid bus bar and run the plus and minus form each battery to those bars. Make sure they are the same length.

    Bill
    2019 GMC 3500 SRW Sierra Denali Duramax
    2020 Reflection 315RLTS

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    Quote Originally Posted by Redapple63 View Post
    Hi Riverbug,

    I think it is close enough in size to parallel then together. One thing I would recommend is to use a bus bar rather than cables to tie the batteries together. Got a good solid bus bar and run the plus and minus form each battery to those bars. Make sure they are the same length.

    Bill
    Thanks Bill. I did plan to use good buss bars. I should have mentioned I am looking at other brands too (such as Ampere Time) which are in the same price range but also have the same recommended charge of 14.6 vs 14.4 for Power Queen. Mainly curious to know if there are any other concerns I should have with mixing and matching brands.
    Chad
    2023 23LDE 965W Solar, Victron Multiplus, Solar Controllers, Cerbo GX, 4x280AH DIY Lithium Batteries, SeeLevel Tank Monitoring, Shock Absorbers (Replaced 2022 22MLE)
    2022 F350 6.7L Superduty, Carbonized Gray, Ultimate Lariat Pkg, 4WD, Crew Cab, 160" Wheelbase, 3.55EL Rear End, 3566# Payload
    Adaptive Steering, Ultimate Camera Pkg, 20" Wheels, 397 Amp Dual Alternator, ARE Topper (Replaced 2004 F150)

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    Rolling Along
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    Quote Originally Posted by Riverbug View Post
    ... Mainly curious to know if there are any other concerns I should have with mixing and matching brands.
    Yes... and no. Generally, mixing battery chemistries is a BiG no-no, but keeping similar voltage LiFePo4 with other LiFePo4 is generally regarded as safe, but not recommended. There are factors to consider, such as capacity, discharge and charge rate, BMS system (some BMS do not like to be paralleled), and then you will have internal resistance differences. So TL&DR you may have issues but probably won't.

    Try to get as close to each other as possible, and don't be surprised if you run into any issues, albeit unlikely.

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    Quote Originally Posted by A.Texas.Yankee View Post
    Yes... and no. Generally, mixing battery chemistries is a BiG no-no, but keeping similar voltage LiFePo4 with other LiFePo4 is generally regarded as safe, but not recommended. There are factors to consider, such as capacity, discharge and charge rate, BMS system (some BMS do not like to be paralleled), and then you will have internal resistance differences. So TL&DR you may have issues but probably won't.

    Try to get as close to each other as possible, and don't be surprised if you run into any issues, albeit unlikely.
    Are the issues primarily related to one "robbing" energy from the other and that sort of thing? Versus a danger of fire risk or something on that order? If not fire or serious issue like that I'd be more inclined to give it a shot, but still need to give it more consideration. I'm so used to lead acid where they have to be purchased new together and identically matched. I'm just not clear about how LiFePo4 compares and how likely it is that doing what I've asked about will result in significant reduction in battery life, usage challenges, or serious problems. Thanks.
    Chad
    2023 23LDE 965W Solar, Victron Multiplus, Solar Controllers, Cerbo GX, 4x280AH DIY Lithium Batteries, SeeLevel Tank Monitoring, Shock Absorbers (Replaced 2022 22MLE)
    2022 F350 6.7L Superduty, Carbonized Gray, Ultimate Lariat Pkg, 4WD, Crew Cab, 160" Wheelbase, 3.55EL Rear End, 3566# Payload
    Adaptive Steering, Ultimate Camera Pkg, 20" Wheels, 397 Amp Dual Alternator, ARE Topper (Replaced 2004 F150)

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    Site Sponsor ajg617's Avatar
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    Quote Originally Posted by Riverbug View Post
    Are the issues primarily related to one "robbing" energy from the other and that sort of thing? Versus a danger of fire risk or something on that order? If not fire or serious issue like that I'd be more inclined to give it a shot, but still need to give it more consideration. I'm so used to lead acid where they have to be purchased new together and identically matched. I'm just not clear about how LiFePo4 compares and how likely it is that doing what I've asked about will result in significant reduction in battery life, usage challenges, or serious problems. Thanks.
    Would different BMS become an issue if they are internal to each battery and different between brands? I seem to recall a conversation with BB that I should even stick with the same form factor for their batteries if I added two more and that was BMS related. My old SW testing background would tell me to look at the edge cases - over voltage charging (I have had this happen), temperature extremes, etc. - anything that the BMS would stress the BMS.
    Robin & John
    2020 Ram 3500 LB SRW 4WD Crew Laramie 6.7HO Aisin, 55gal Titan
    2022 Solitude 310GK-R - Dual pane, factory solar & Onan, 8K axles with discs, 18K GVWR, W/D, Heat Pump, Goosebox, Battleborn

    2023 stays

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    Quote Originally Posted by Riverbug View Post
    Are the issues primarily related to one "robbing" energy from the other and that sort of thing? Versus a danger of fire risk or something on that order? If not fire or serious issue like that I'd be more inclined to give it a shot, but still need to give it more consideration. I'm so used to lead acid where they have to be purchased new together and identically matched. I'm just not clear about how LiFePo4 compares and how likely it is that doing what I've asked about will result in significant reduction in battery life, usage challenges, or serious problems. Thanks.
    Fire risk is minimal as long as you have a properly functioning BMS (whether internal built into battery or external) and wiring/fuse is correctly matched. A BMS should prevent battery fire issues (emphasis on should).

    It's mostly functional issues and it really depends on how you'll use the system. If you are constantly going from 100% to 0% and back you'll likely have a BMS that disconnects before the other when charging and/or discharging due to capacity mismatch. Depending on you amp draw, the internal resistance could cause one battery to run hotter (i.e. less efficient) and cause it to drain faster or run wire hotter (again less efficient). Both the previous scenarios could cause voltage differences between the batteries which would not be great.

    If you are using low amp draw (like 1/4C discharge) and running the batteries in the 10-90% charge rule, and only have a few batteries, you probably won't experience huge issues outside BMS compatibility. But when you start adding large watt/hour capacities and multiple batteries, that's when you can really start running into issues.

    That's ONE of the reasons BattleBorn really are some of the best batteries out there. BB's internal cells are all matched and tested to be as close to capacity, internal resistance, and voltages with a quality BMS, as best a profitable business can do. Not advocating for them, because I assemble my own cells fin China and BB cells are $$$$ (for good reason), but pointing out why you can take 10 BattleBorn batteries in parallel and have minimal issues.

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    Quote Originally Posted by ajg617 View Post
    Would different BMS become an issue if they are internal to each battery and different between brands? I seem to recall a conversation with BB that I should even stick with the same form factor for their batteries if I added two more and that was BMS related. My old SW testing background would tell me to look at the edge cases - over voltage charging (I have had this happen), temperature extremes, etc. - anything that the BMS would stress the BMS.
    Yes, depending on the BMS. There are even BMS that don't work well with paralleling with the same BMS. You'll often see cheaper batteries that say, "Do not parallel more than XX batteries" for this reason. If the BMS is properly functioning, it should not allow an under or over voltage situation.

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    Site Sponsor ajg617's Avatar
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    Quote Originally Posted by A.Texas.Yankee View Post
    Yes, depending on the BMS. There are even BMS that don't work well with paralleling with the same BMS. You'll often see cheaper batteries that say, "Do not parallel more than XX batteries" for this reason. If the BMS is properly functioning, it should not allow an under or over voltage situation.
    Just to clarify, I didn't have an over voltage situation with the BMS, just with the Solar controller overcharging by .1V which caused no battery issues, but did cause a hiccup with my PD-9160ALV.
    Robin & John
    2020 Ram 3500 LB SRW 4WD Crew Laramie 6.7HO Aisin, 55gal Titan
    2022 Solitude 310GK-R - Dual pane, factory solar & Onan, 8K axles with discs, 18K GVWR, W/D, Heat Pump, Goosebox, Battleborn

    2023 stays

  10. #10
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    Thanks @A.Texas.Yankee and @ajg617 - after your comments about the BMS etc., it prompted me to review more about this on the SOK website and came across a page that states you should "not mix different capacity or model batteries". So that tells me if I shouldn't mix within the SOK brand I definitely shouldn't mix different brands. Apologies for not seeing that sooner and taking up everybody's time. I really appreciate the responses!
    Chad
    2023 23LDE 965W Solar, Victron Multiplus, Solar Controllers, Cerbo GX, 4x280AH DIY Lithium Batteries, SeeLevel Tank Monitoring, Shock Absorbers (Replaced 2022 22MLE)
    2022 F350 6.7L Superduty, Carbonized Gray, Ultimate Lariat Pkg, 4WD, Crew Cab, 160" Wheelbase, 3.55EL Rear End, 3566# Payload
    Adaptive Steering, Ultimate Camera Pkg, 20" Wheels, 397 Amp Dual Alternator, ARE Topper (Replaced 2004 F150)

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