Battery monitor

A battery monitor is a device that looks at your battery and tells you all kinds of useful things about it's health.

An alternative energy installation without one is a little bit like a car without a dashboard, it will work but is makes it much harder to make sure that you are not doing anything illegal (read over / undercharging your battery) or bad.

Most battery monitors work by measuring the voltage drop across a very small resistor called a 'shunt'. Typically this shunt will produce 50 mV when 500 Amps of current is passing through it. Combining the measurement of this current, the battery voltage and some information that you give it about your setup will allow the battery monitor to work out the state of health of your battery with some accuracy, and it will help you to diagnose trouble before it becomes a real problem.

In our system we have used a Trace 'E-Meter', it's a little round device that you connect with a long shielded cable to the shunt. You mount it with a single hole in a wall or some other convenient spot in your home so you can keep an eye on it without descending into wherever you have decided to place your system.