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Have I damaged my batteries?

lightmail

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May 6, 2021
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Help.. My system got up to 14.4 in the sun and then settled around 13.3. I then plugged in a 1200 watt load. Within minutes it showed 12.7 volts. Turned off load. So I turned on shore power and it took the charger about 20 mins to charge to 14.4-14.6. It showed bulk, then absorp then into float and shut down. Tried load again and did the same thing. I have it set to lithium. Can't get my shunt to work yet. Should I continue running the load till the bms shuts down the battery. It seems to me that the batteries are not accepting a charge from solar or shore power. Thanks for any help...
 
How big and what type is the battery?

I would also ask that when the 1200 watt load was shut off, what did the voltage settle to?

The Lithium battery I’m working on is 24 volts and settle to 26.7. So at 12 volts, your battery settles to about what mine does.

If you’re charging to 14.6, that is 3.65 per cell. If you have any way to keep lower, that’d help the batteries.
 
Eh. 12.7v with a 1200w load isn't necessarily a problem as long as the voltage comes back up when you take the load off.

Might indicate some connections need improvement though.
 
From what you describe, it sounds like your inverter is cutting off due to the Voltage Drop. With 12V delivering 100A that sag will be fairly noticeable depending on the cells being used. You should try to set the Inverter cutoff to 10.4V which is 2.600 Volts per cell. The absolute bottom is 2.500 Volts per cell. LFP's working voltage range 3.000-3.400 volts per cell (12.0-13.6V) (cell voltage nominal being 3.200).

A Note of caution, when running this load, the wires may get "warm" but if they get hot, STOP, heat is a bad sign and time and time to look at the wiring and configuration for anything loose etc.

There is a link in my signature for an LFP Voltage Chart which you may find useful to have at hand, it's a downloadable PDF.
Hope it helps, Good Luck
 
How big and what type is the battery?

I would also ask that when the 1200 watt load was shut off, what did the voltage settle to?

The Lithium battery I’m working on is 24 volts and settle to 26.7. So at 12 volts, your battery settles to about what mine does.

If you’re charging to 14.6, that is 3.65 per cell. If you have any way to keep lower, that’d help the batteries.
2 100ah Sok 12 volt. when shut off voltage went to 13.2-3
 
From what you describe, it sounds like your inverter is cutting off due to the Voltage Drop. With 12V delivering 100A that sag will be fairly noticeable depending on the cells being used. You should try to set the Inverter cutoff to 10.4V which is 2.600 Volts per cell. The absolute bottom is 2.500 Volts per cell. LFP's working voltage range 3.000-3.400 volts per cell (12.0-13.6V) (cell voltage nominal being 3.200).

A Note of caution, when running this load, the wires may get "warm" but if they get hot, STOP, heat is a bad sign and time and time to look at the wiring and configuration for anything loose etc.

There is a link in my signature for an LFP Voltage Chart which you may find useful to have at hand, it's a downloadable PDF.
Hope it helps, Good Luck
My inverter slowly comes down in amps and then shuts down. It shows the stages. It doesn't seem to be shutting off immediately. When it reads 12.7 should I just keep running and see if inverter shuts down. It's suppose to do that. I have 2/0 and have a total distance round trip of 11.6 feet. Connections are tight but I will double check. Should I try running it at 12.7 and see what occurs. Thanks for response
 
2 100ah Sok 12 volt. when shut off voltage went to 13.2-3
From what you describe, it sounds like your inverter is cutting off due to the Voltage Drop. With 12V delivering 100A that sag will be fairly noticeable depending on the cells being used. You should try to set the Inverter cutoff to 10.4V which is 2.600 Volts per cell. The absolute bottom is 2.500 Volts per cell. LFP's working voltage range 3.000-3.400 volts per cell (12.0-13.6V) (cell voltage nominal being 3.200).

A Note of caution, when running this load, the wires may get "warm" but if they get hot, STOP, heat is a bad sign and time and time to look at the wiring and configuration for anything loose etc.

There is a link in my signature for an LFP Voltage Chart which you may find useful to have at hand, it's a downloadable PDF.
Hope it helps, Good Luck
 
My inverter slowly comes down in amps and then shuts down. It shows the stages. It doesn't seem to be shutting off immediately. When it reads 12.7 should I just keep running and see if inverter shuts down. It's suppose to do that. I have 2/0 and have a total distance round trip of 11.6 feet. Connections are tight but I will double check. Should I try running it at 12.7 and see what occurs. Thanks for response
How big and what type is the battery?

I would also ask that when the 1200 watt load was shut off, what did the voltage settle to?

The Lithium battery I’m working on is 24 volts and settle to 26.7. So at 12 volts, your battery settles to about what mine does.

If you’re charging to 14.6, that is 3.65 per cell. If you have any way to keep lower, that’d help the batteries.
 
From what you describe, it sounds like your inverter is cutting off due to the Voltage Drop. With 12V delivering 100A that sag will be fairly noticeable depending on the cells being used. You should try to set the Inverter cutoff to 10.4V which is 2.600 Volts per cell. The absolute bottom is 2.500 Volts per cell. LFP's working voltage range 3.000-3.400 volts per cell (12.0-13.6V) (cell voltage nominal being 3.200).

A Note of caution, when running this load, the wires may get "warm" but if they get hot, STOP, heat is a bad sign and time and time to look at the wiring and configuration for anything loose etc.

There is a link in my signature for an LFP Voltage Chart which you may find useful to have at hand, it's a downloadable PDF.
Hope it helps, Good Luck
From what you describe, it sounds like your inverter is cutting off due to the Voltage Drop. With 12V delivering 100A that sag will be fairly noticeable depending on the cells being used. You should try to set the Inverter cutoff to 10.4V which is 2.600 Volts per cell. The absolute bottom is 2.500 Volts per cell. LFP's working voltage range 3.000-3.400 volts per cell (12.0-13.6V) (cell voltage nominal being 3.200).

A Note of caution, when running this load, the wires may get "warm" but if they get hot, STOP, heat is a bad sign and time and time to look at the wiring and configuration for anything loose etc.

There is a link in my signature for an LFP Voltage Chart which you may find useful to have at hand, it's a downloadable PDF.
Hope it helps, Good Luck
My inverter slowly comes down in amps and then shuts down. It shows the stages. It doesn't seem to be shutting off immediately. When it reads 12.7 should I just keep running and see if inverter shuts down. It's suppose to do that. I have 2/0 and have a total distance round trip of 11.6 feet. Connections are tight but I will double check. Should I try running it at 12.7 and see what occurs. Thanks for response
 
OP: "My inverter slowly comes down in amps and then shuts down. My inverter slowly comes down in amps and then shuts down."
The Amp should go up as the Voltage goes down for it to maintain Output power of the inverter.
 
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