LBCO Voltages...

johnTjohnT Registered Users Posts: 15 ✭✭
Does anyone know at what voltage a 48v system will be around 50% (approximate range)? This seems to be an area with a wide variety of opinions. I realize that it will vary from battery bank to battery bank, but it seems that there would have to be a normal range that most relatively healthy battery banks would fall into.

Here is what it says in the manual of the Magnum ME-RC Remote under setting the LBCO:
"Where do I set the LBCO setting?
If you want to cycle the batteries
slightly – but don’t want to discharge them more than 20%*, then the
LBCO setting should be set from 11.5 to 12.2 VDC (12-volt models), 23.0
to 24.4 VDC (24-volt models), or 46.0 to 48.8 (48-volt models). In some
applications, such as those installed in an off-grid home or when doing a lot
of dry-camping in your RV, you may want to cycle down to 50%* by setting
the LBCO from 10.0 to 11.4 VDC (12-volt models), 20.0 to 22.8 VDC (24-volt
models), or 40.0 to 45.6 VDC (48-volt models). In extreme circumstances,
you have the ability to discharge the batteries to 80%* by setting the LBCO
to 9.0 or 9.5 VDC (12-volt models), 18.0 or 19.0 VDC (24-volt models), or
36.0 or 38.0 VDC (48-volt models) before recharging."

I would just go by this, but I have seen a lot of opinions from what seem like knowledgeable people that would greatly disagree with those voltages. Some say that 50% is closer to 48.0 VDC, which is a vast difference from "40.0 to 45.6 VDC", and some would say that at 40.0v a battery bank would be basically fully discharged (which is obviously not good). With rainy season setting in here, I know I am going to be cycling my batteries deeper than I was when it was sunny most days, but I would still like to keep from going below 50%...I just need to know where that range is. I also realize that there is a big difference between resting voltage and under load. But in reference to LBCO, I don't know why anyone would be talking about resting voltage, since that would not apply.

Over time, I have come to trust the information and opinions on this forum more so than any other, but I haven't been able to find much on here about it. Any information would be greatly appreciated. Thanks


  • Dave AngeliniDave Angelini Solar Expert Posts: 6,131 ✭✭✭✭✭
    The XW + system uses 46V with a 10 second test time and a new hysteresis set-point that I have been just leaving at the default.
    The older XW systems were always 44V and 22V for lights out after 600 seconds. They come back-up after sunrise if you have sun....
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
    E-mail [email protected]

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