Map Actual State-Of-Charge & wake up DALY 12V BMS

[diyhabitat]

I have an ENERDRIVE ADVENTURER 12VDC charging & inverter system that is powered by a CALB 12V 240Ah LiFePO4 battery with a DALY 12V 4S 250A battery management system (BMS). I progressively discharged the CALB 12V battery & recorded the voltage versus State-Of-Charge (SOC) % in order to obtain an accurate Actual measure of SOC% rather than rely on the theoretical factory-set SOC% in the BMS. The BMS shut down when the CALB battery voltage dropped below 10.4V. In this video, I wake up the BMS by using the Battery Reset button on the ENERDRIVE ADVENTURER - after I temporarily connected a sealed lead-acid 12V 18Ah battery to the ENRDRIVE ADVENTURER system. I include 2 graphs which show the theoretical SOC% compared to the Actual SOC% I measured through an ENERDRIVE ePRO PLUS shunt. The graphs show clearly why it is not reliable to depend on voltage of an LiFePO4 battery to determine its SOC%. A better way is to use a shunt connected inline to the negative terminal of the battery.