I have an Arduino board with a pump attached to it, and for powering both, I'm using a 18650 battery cell with a DC-DC Boost Converter. I plan to leave it working even when I'm not home, and I know that if the battery over discharges, there will be trouble, so I would like to design an over-discharge protection board.
I can see from this video that it is not a big deal to build one, however, I don't have a battery alarm buzzer. Is there any way to build such a protection board without that part?
Or is there any simpler way to build such a circuit with the components that I have: a relay (JQC-3F(T73)), some diodes (N4007 type), capacitors(22, 47 and 100uF) a potentiometer, a bunch of resistances (from 1mΩ to 51 kΩ) and transistors (PNP-8550, NPN-8050 and IRF520).