I installed a battery monitor in our camper. It cost less than $20.00, and gives far more information than the OEM battery monitor. Among its various features is an alarm to indicate when the battery voltage drops below a set level.
The monitor is mounted on an interior wall that is near the converter so I could access the necessary connections. It must be connected to the battery's positive terminal, and a shunt (included with the monitor) installed in series with the wire directly connected to the battery's negative terminal. The other end of the shunt also connects to the monitor. The shunt enables the it to determine the total current being supplied by the battery. I used telephone wire (remember when the phone was hardwired and bolted to the wall?) to connect the display. It requires a total of 4 light weight wires. Telephone wire is perfect because it conveniently consists of 4 color coded wires in a single cable and it only costs 19 cents a foot!
The monitor displays the instantaneous battery voltage and current (amps). Form these values it calculates the instantaneous power (watts) and calculates the cumulative energy (watt-hours) used since the monitor was last reset. It has a switchable backlite to illuminate the display if needed. The picture was taken with everything OFF. The .2 amps therefore is the total of the parasitic loads (Propane/CO detector and radio).
The monitor is mounted on an interior wall that is near the converter so I could access the necessary connections. It must be connected to the battery's positive terminal, and a shunt (included with the monitor) installed in series with the wire directly connected to the battery's negative terminal. The other end of the shunt also connects to the monitor. The shunt enables the it to determine the total current being supplied by the battery. I used telephone wire (remember when the phone was hardwired and bolted to the wall?) to connect the display. It requires a total of 4 light weight wires. Telephone wire is perfect because it conveniently consists of 4 color coded wires in a single cable and it only costs 19 cents a foot!
The monitor displays the instantaneous battery voltage and current (amps). Form these values it calculates the instantaneous power (watts) and calculates the cumulative energy (watt-hours) used since the monitor was last reset. It has a switchable backlite to illuminate the display if needed. The picture was taken with everything OFF. The .2 amps therefore is the total of the parasitic loads (Propane/CO detector and radio).
If you are considering installing one of these monitors, here is some information that may help.
Before you begin, disconnect shore power, and disconnect your battery. You can probably access all the necessary connections in the wiring behind your converter. So if you can access that area it is the place to start.
This is a picture of the back side of my converter. As you can see neatness is not a priority during factory assembly! Look for a bus bar that gangs many of the negative returns from various camper accessories (lights, fans, refrigerator etc.) One of these wires will return to the battery negative terminal and so carries all the current from all the camper's electrical systems. This is the wire to disconnect and connected to the shunt. You must supply another wire (8 gauge) between the other shunt terminal and the disconnected bus terminal. It might be tricky to find the correct wire to disconnect from the bus. In my case it was the only wire from the bus that went through the floor so that's something to look for. To verify you have the correct wire disconnected, reconnect your battery and check that no 12 volt accessory works.
The positive 12 volt connection should be easier to find. At the back lower left of my converter are a red and black wire. If you remove the converter front panel you will see these are tied together at a terminal labeled +12 volts.
Before you begin, disconnect shore power, and disconnect your battery. You can probably access all the necessary connections in the wiring behind your converter. So if you can access that area it is the place to start.
This is a picture of the back side of my converter. As you can see neatness is not a priority during factory assembly! Look for a bus bar that gangs many of the negative returns from various camper accessories (lights, fans, refrigerator etc.) One of these wires will return to the battery negative terminal and so carries all the current from all the camper's electrical systems. This is the wire to disconnect and connected to the shunt. You must supply another wire (8 gauge) between the other shunt terminal and the disconnected bus terminal. It might be tricky to find the correct wire to disconnect from the bus. In my case it was the only wire from the bus that went through the floor so that's something to look for. To verify you have the correct wire disconnected, reconnect your battery and check that no 12 volt accessory works.
The positive 12 volt connection should be easier to find. At the back lower left of my converter are a red and black wire. If you remove the converter front panel you will see these are tied together at a terminal labeled +12 volts.
