Battery systems for stationary applications

  • Thread starter Thread starter Landshark
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R P said:
Can you not shut down your grid tie-in and shut off your inverter leaving only the PVs on charging the battery?
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I can. Doing those things would create a set of conditions under which the system never operates.

Again, there is no load on the batteries unless there is a loss of grid power. The panels provide a float charge in the daytime and the grid does the same at night.
 
OK, but I know on mine when everything is connected, even when there is no load, the reading is different than when I totally disconnect it, and only the PVs are on. IE the reading is higher, 55.4, when it is disconnected. Drops a couple decimals when it is connected, even with no load. With any slight load it drops more.

Next time I am up there will look at it more closely. I am reluctant to change the setting based on my past experience with charging at home, where the batteries failed to reach full charge, 6.36 without the 13.8v float.
 
R P said:
I am reluctant to change the setting based on my past experience with charging at home, where the batteries failed to reach full charge, 6.36 without the 13.8v float.
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In order to make an informed decision you’ll need to know the float voltage that is specified by the manufacturer of the batteries that you’ve installed at the cabin. Right now, you’re just guessing.
 
The battery specs all give 13.5 as their float voltage. I am going to check more closely the voltages at my battery. While the charger says 13.8, the actual battery voltages may be less.

I have not had any excessive water usage with my batteries, very little actually. I know that is an indication of over charging. I also have not been on the solar forums for a long time. Will check them out again.

I do find it a little odd that the while the battery specs say 13.5, all the chargers default to 13.8 for their FLA float mode.
 
R P said:
I do find it a little odd that the while the battery specs say 13.5, all the chargers default to 13.8 for their FLA float mode.
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FWIW: The float voltage for our L16’s is set at 54.0V. Below is a screenshot which shows the information for the portable 48V charger that we have as a backup. The float voltage is 54.24V. IMG_2611.webp
 
One thing I haven't checked for a while is the SG of my batteries. When at float charge, the cells should be 1.625 or higher to indicate a full charge. And if I lower the float voltage, want to ensure that SG is still maintained.
 
R P said:
One thing I haven't checked for a while is the SG of my batteries. When at float charge, the cells should be 1.625 or higher to indicate a full charge. And if I lower the float voltage, want to ensure that SG is still maintained.
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Typo?

You’ll want to se a SG of 1.26-1.28 at 80F. IMG_2612.webp
 
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