Fitting the Victron Battery Monitor

With little else to do today it seemed like a good idea to make a start on fitting the Victron BMV600 battery monitor.  What I should have done instead was sit around and drunk tea!  Anyway, the first think to do was collect all the tools and equipment to complete the task.  This reduces the number of times the managing director and chief financial controller has to be called to ask for assistance.Note the word ‘reduce’ rather than ‘eliminate’ is used.

The shunt for the BMV is connected between the main battery negative terminal and all the negative return cables.  So the first task was to remove all the cables and clean the terminal prior to fitting the new ‘connector’ cable.

All the negative cables have been removed from the main battery bank negative terminal and the ‘connector’ cable which will be connected to the primary side of the shunt has been fitted.  The smaller black cable goes to the Sterling PDAR and doesn’t need to be connected to the secondary side of the shunt.  It was at this point I made my mistake erred in my judgement.  I forgot to reattach the main negative connector cable from the other battery! 

The next step was to fit the shunt and mounting bracket.

Room was at a premium but eventually it was fitted in place and I could start connecting all the cables

I had just finished struggling to connect the battery connector lead to the secondary side of the shunt (and it was a struggle) when I realised I’d been a “dolt” and the lead had to connect directly to the main negative battery terminal.  That meant dismantling everything to fit the cable to the correct terminal.  Of course I’d already heavily smeared Vaseline all over the terminals so the remainder of the job was a rather sticky task.

As you can see in the photo above the connector cable between the battery terminal and the shunt is installed (purple arrows).   All the negative return cables are now connected to the secondary side of the shunt (green arrow) and the shunt power and data cables have been connected (blue arrow).

I don’t have a 2” circular hole saw so the Victron gauge hasn’t been fitted.  However it has been connected to the data cable and is giving a reading of 12.72 and 12.75V.

The SmartGauge is displaying the voltage as 12.75V

There are two outstanding tasks before the installation is complete.  The gauge has to be fitted and I need to go back into the engine compartment and secure the data cable with some plastic cable ties.

Now all we I need to do is watch how many amps flow in and out of the battery bank!

“Houston this is Apollo 13….. we have a problem!”

After starting the engine and running it for an hour there was no increase in the battery bank state of charge and the Victron was only reporting amps going out of the batteries with nothing going in!  I was sure everything had been correctly reconnected.  Back down the engine bay I went like a rabbit down its hole!  Cuddling an engine that has the “hots” for you is no longer a delight.  There it was…. dangling off to one side….. the negative cable off the main alternator.  Must have been a “seniors moment” failing to reconnect it. As usual; it had to be connected to the most difficult of the terminals.  Well it’s done now and the Victron initially reported 168 amps flowing into the batteries but that has now settled down to 85 amps.