Custom Sensor - DC Battery Monitor

A voltage divider can be used to measure DC voltages greater than the 2V limit of the mPort.  This is useful for applications such as solar batter monitoring.

 

The voltage divider in this example is 1: 26.4 (13 / (330 + 13)), so the resistor values in this example handle up 54 volts. The diagram shows 24V DC which is a common solar battery voltage.  For voltages higher than 54v the resistor values can be adjusted.

 

Example Connection:

 

Or the circuit can be wired directly to the mPort terminal block.

 

Custom Sensor Definition (configured in the bottom panel of the mFi controller):

"DC Battery Monitor" : {
"desc" : "0-54 VDC",
"conversion" : "xyz*26.4",
"analog" : true,
"rj45_v1" : true,
"tblock_v1" : true,
"rep_analog" : 1,
"default_tag" : "volts",
"analog_tag" : "volts",
"unit" : "vdc",
"precision" : 4
}