time2roll wrote:
Yes you can drag a FLA battery to 10 volts and shut down at 50% charge still on the battery.
Lithium voltage does not sag near as much at high load so the battery can be discharged right to BMS cut-off and the battery is fully depleted.
The BMS cut- off setting is based on a resting SOC voltage, while the actual trigger voltage will be the loaded voltage as seen at the battery end of the battery-inverter wiring.
You want to operate to a low SOC, but the loaded voltage might trigger the BMS before you can operate that low. Must depend on the battery AH and the size of the load.
I guess we need some numbers, but I don't have any. Itinerant1 has some numbers, but for a 500AH bank of LFP, and he says "avoid the knees" for his chosen operating range.
In this case the OP wants a 120AH LFP with a 1000w inverter so max DC 100 amp draw. What is the 120AH LFP's discharge current /voltage at 100 amps at say 30% SOC (curves and tables for that somewhere)
