I have a circuit that is draining my Li-Ion batteries far too low. In some cases it is destroying the batteries. Because of this, I would like to create a low voltage cutoff but I have a couple of questions. My power source is two 123-a 3.7V 800mAh batteries in series. I have a voltage regulator producing a constant and stable 3.3V for the circuit. I am considering using a MOSFET to switch the power off when the batteries get too low. However, I am unfamiliar with these and I am unsure which one to get. The circuit draws anywhere from 70mA to 200mA when on, which is in timed intervals. When off, it draws almost no current. And, as described above, it needs a constant 3.3V.
1) Do I need a low voltage cutoff(LVC) for each battery or can I place one LVC after the 2 batteries in series? I was worried one battery would still over drain.
If I only need one LVC, then the on voltage could range from 5V+ and the off voltage would need to be at 3.5V or less
1) Any suggestions on which MOSFET to choose here?
2) Should I use a BJT instead? And if so, suggestions on which one?
1) Do I need a low voltage cutoff(LVC) for each battery or can I place one LVC after the 2 batteries in series? I was worried one battery would still over drain.
If I only need one LVC, then the on voltage could range from 5V+ and the off voltage would need to be at 3.5V or less
1) Any suggestions on which MOSFET to choose here?
2) Should I use a BJT instead? And if so, suggestions on which one?