Camper Trailers Tech Tips

Ammeter Box





Ammeter Box


    I have a decent voltmeter permanently fixed in the 4WD on a four position switch to the batteries (OFF plus 4WD, 4WD AUX and Trailer). This allows me to monitor the charge going into each battery from the alternator and the state of the batteries at any time when the engine is off. However as two of the batteries, (4WD AUX and Trailer) are permanently connected to solar panels (which means they are getting a charge unless its dark), this state of charge reading can be distorted as the panels are always showing some charge going in rather than just the resting state of the battery.

    All of my generating power units (all batteries, extra solar panel, petrol generator, smart charger) are fitted with 50A Anderson plugs (the main battery has a 175A Anderson for the winch) as I find this is easier to connect to the batteries (especially as the Land Rover batteries are under the passenger seat). Similarly some of my equipment (air compressor, portable winch) is also fitted with Anderson plugs for easy access to power.

    I recently got an inverter from Jamie Hazelden at Dynamic Solar Solutions and thought it would be handy to know what sort of draw it had on the battery. It also occurred to me it would be good to be able to measure the power going in from the solar panels, generator and battery charger.

    As a result I made this ammeter box which can be fitted between supply and demand equipment to measure the flow of current. The easiest way is via the two Anderson plugs on the side of the box but I thought I might as well add some banana/screw terminals as well so that it would measure input/output to anything using various leads I always carry. These are conversion leads which allow me to power just about anything from anything, for example the inverter fitted with a dual cig plug/merit (male) from a 50A Anderson plug.



10kb pdf download



ammeter wiring diagram portable ammeter

12kb pdf download

diagram of my setup/equipment. GREEN are power inputs, BLUE are power equipment, and YELLOW (the batteries) can be output and input dependant on requirements


26kb pdf download

various leads and connections various leads and connections

11kb pdf download

 leads and connections list portable ammeter in action


50A & 175A Anderson plugs for main and Aux batteries mounted under passenger seat voltmeter and 3 position switch to monitor batteries

Thanks to Mike Sargeant



december 2008