Camper Trailers Tech Tips

Victron BMV-600S




Victron BMV-600S
 intelligent battery monitor

    One of the things that annoyed me about depending upon battery power while camping was never really knowing how much power I had left in the batteries. You can apply a voltmeter to the terminals, but this is a wildly inaccurate way of gauging the state of charge. The reading can suggest your battery is fully charged when it is actually less than half charged thanks to surface charge. I think I have now solved the problem.

    I have installed a Victron BMV-600S to my camper. This is an intelligent battery monitor which keeps track of all the current flowing into and out of the batteries and even calculates the Charge Efficiency Factor as it goes and uses Puekert’s Exponent (Google it if you want to know...) to be as accurate as possible.

    To set it up you connect the supplied 500 Amp shunt to the battery negative terminal and then connect all the negative wires to the “load” end of the shunt. This allows the monitor to keep track of all current movements. The shunt needs a light wire (supplied) connected to the positive post to do its magic. You then connect the Monitor to the shunt with the supplied network type cable which is 10 metres long, certainly long enough for any camper trailer use!

    You mount the gauge in a suitable spot, feed it the setup data like battery type (AGM, GEL, WET, etc.), total capacity, etc. – up to 28 different parameters if you want to - and then zero everything with the batteries fully charged.

    The monitor now keeps track of all the current flows and does the math. The LCD readout on the monitor can be scrolled through displays of

  • Battery Voltage (V)

  • Current (I), either positive or negative, depending upon what is going on

  • Consumed Amp hours (CE), since the battery was last fully charged

  • State of Charge (SOC) as a percentage, to one decimal place

  • Time To Go (TTG) which gives you a rough estimate of how long before you really need to recharge the batteries - 50% SOC by default- based on the current flows over a user selectable time, up to 12 minutes.

    There is also another connector on the rear of the Monitor which can be used to turn on a generator automatically once a user set State of Charge threshold is reached. The State of Charge display is about as accurate a measure of your batteries’ current energy capacity as you will get. The more I use it, the more impressed I am. 




battery voltage


energy used



state of charge

time to go


 thanks to David Jones


may 2011