Battery Low Voltage Alarm

I am looking for a voltage sensor that I can use to trip a low voltage alarm for a 12S9P Li-Ion battery configuration. The battery operating voltage is between 45.3V max – 30V min. Manufacture recomended low voltage for this configuration is 30 volts, I would like to trigger a low voltage alarm approx 31.5 Volts decending. I also have a 4S9P Li-Ion battery configuration using the same Li-Ion cells that I would also like to have a low voltage alarm for, 15V Max – 10V min, with alarm at 11.0 volts decending.

I am using 1383 Simple High-Power Motor Controllers to control the main propulsion motors which have low voltage cut-off capability, but I want to know ahead of time so that I can retreive my boat before it goes dead in the water.


Unfortunately, we do not carry any low voltage battery alarms nor do we have any straightforward solutions for measuring large voltages like 30V. You might consider using a low voltage buzzer alarm if you think you could hear it at the distances you normally control your boat. It looks like places like HobbyKing carry those kinds of alarms for up to 8S LiPo/Li-Ion batteries.