Like all Li+ batteries, the voltage stays fairly constant for most of the capacity, and then dives at the end.  An LBCO of 48 v or lower, is not going to work in my experience.  The SOC vs V chart for the Powerflo doesn't look any different than most other brands.    You'll end up with the BMS shutting the battery off, which will then not allow it to accept charging from the (hopefully) DC coupled PV array.  Then you're in for dark start, where you need to bring a 48 vdc power supply of some sort that can output 48 vdc even to a 0 v buss to wake the BMS up.

Basically a well pump or other large load will pull the battery voltage down so hard and fast that it will occasionally get past even an LBCO set at 49 v (max available setting on Magnums)  I agree with Wallace here, that you want a setting above 50 v, to be useful.  You need enough SOC left to make up for the self discharge of the battery and BMS, so the charge controller can wake up the next sunny morning.

All of this depends on the time and current programming that are behind that LBCO function.   Most LBCO setups are designed to allow high current for short time periods, which means the BMS may beat it to the shutdown.   Offgrid, especially with legacy inverters, this is a very real problem, and one reason I'm still using lead acid batteries in some systems.

Homegrid batteries are wired with one less cell in series for closer to true 48 v performance, but I can't recommend them yet, because I've had some firmware glitches with the one system I've tried them on.

Ray Walters
Remote Solar

On 2/4/2025 9:07 AM, Wallace Stahle via RE-wrenches wrote:
Hi Jeremy,

I am under the impression that leaving at least 10% of capacity will extend total cycle life.
The chart states 50.4 volts is a 10% SOC.
 Then there is the LBCO delay time that may allow battery shutdown before the inverter does.

Of course the  OB FX LBCO upper limit is at 48 volts thus the recent search and discussion for a seamless external inverter shutdown to get users attention if an AGS is not in the mix.

Wallace Stahle
Future Electric Energy Co
PO Box 236
Willits, CA 95490
707-459-0474
Lic.#C10-762093
[email protected]

On Feb 3, 2025, at 7:11 PM, Jeremy Rodriguez via RE-wrenches <[email protected]> wrote:

Today I installed 3 of the MN
POWERFLO 5 batteries with an OBVFX3648
Per the battery label I was able to set the inverter LBCO to 46 vdc.
I see that the battery BMS range
Is 44.8-58 vdc
We should be good to go.


Jeremy Rodriguez
Solar Installation / Design
All Solar, Inc.
1453 M St.
Penrose Colorado 81240

Sent by Jeremy's iPhone. Sorry for typos and shorthand.

On Feb 3, 2025, at 1:47 PM, Nick Lucchese via RE-wrenches <[email protected]> wrote:


Here is the voltage vs SOC approximation chart from Midnite. Was helpful for me on my first couple installs as I awaited some additional details about their batteries.

Nick

On Mon, Feb 3, 2025 at 6:50 AM William Bryce via RE-wrenches <[email protected]> wrote:

    Hi Jay

    The settings for the MNS Batteries are on a sticker on each
    battery.

    BMS- LVCO 44.8 HVCO 58V (The HVCO is not on the sticker)
    LVCO (inverter) 46.0
    Float 54V
    Bulk 56.1V

    The rest of the  you can set to what you want, the battery does
    not care.
    All Prismatic cells operate mostly the same, and the MNS
    Batteries use A+ Automotive cells MFG by EVE.

    Thanks

    Logan


    On Mon, Feb 3, 2025 at 8:47 AM Jay via RE-wrenches
    <[email protected]> wrote:

        Hi Bill

        I tried and failed to find any setting information on that
        battery besides charge and float.
        Kinda need to know things like LVD, recommended LBCO, etc.
        But if it’s similar to other prismatic cells you should be
        able to set the OB inverter to a LBCO that works without
        having to go through a aux relay.

        Jay

        > On Feb 2, 2025, at 9:53 PM, Bill Battagin via RE-wrenches
        <[email protected]> wrote:
        >
        > Have any off-gridders done a system with Powerflo16's to
        power pre-LFP OB/FX inverters?  The FM80's LFP settings in
        this system are compatible with LFP but I'm looking for
        options other than using the Aux in the CC's wired to a NC
        relay and from there to the inverter on/off landings in the
        green terminal of the OB/FX for the LBCO and reconnect function.
        >
        >             I've been down this road before, though a
        different equipment.  I've used the Aux from a Classic for
        inverter LBCO and reconnect though its never been fully
        "tested", although I read "open" and closed" at the un-wired
        aux landing when I forced it with a high LBCO setting.  Just
        thinking about the highest reliability.
        >
        >         Thanks in advance.
        >
        > Bill
        >
        > Feather River Solar Electric
        > Bill Battagin, owner
        > 4291 Nelson St. (Shipping)
        > 5575 Genesee Rd. (USPS, UPS)
        > Taylorsville, CA  95983
        > 530-284-7849, 258-1641(cell)
        > CA. C10 Lic # 874049
        > Solar Powered since 1982
        > Home of the Sunny Side Up
        >
        >
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