Link 10 Battery Monitor

[transmitterdan]

It is trivial to tell if charge is going in or coming out of a lead acid battery using a volt meter. The break point is about 12.6-12.7V. More than that and charge is going in. Less than that and charge is going out. This assumes there is some load connected to the battery. There are simple analog meters with colored scale markings that use this technique. In the digital age we have forgotten some simple ideas from the past.

[Maine Sail]

Originally Posted by Tootsie

So I am figuring it should be possible to buy an instrument connected to the battery poles, making it possible to read off whether the bank is being discharged or charged....
Am I wrong?

A shunt simply gets inserted into the battery negative cable and all loads and charge sources go on one side of the shunt (normally called the "load side" and NOTHING sneaks past it and winds up on the battery side of the shunt except for the battery bank.

All you will need is a short jumper wire the same gauge as your main battery cables to go from battery negative post to the battery side of the shunt. The negative cable that was on the neg battery post is simply moved to the load side of the shunt.

A Victron BMV-600 is a very, very easy install, the calibration often takes more time than the installation...

The Victron BMV-600 comes standard with a 500A 50mV shunt...