12 Volt Battery Monitors
12 Volt Battery Monitors . Get a wholesale 12 volt battery monitor for convenient testing of battery state on alibaba.com. A voltage greater than 5 volts may blow the pin or fry the nodemcu. A Victron Battery Monitor Victron, RV / Marine Cellpower from www.cellpower.co.nz It works on 3.3 volts. Nodemcu is a tiny device; The fresh water pump is also 12v.