After you've spent a lot of time and money on setting up your Renewable Energy System, the first thing you want to know is…IS IT WORKING? The first pieces of equipment you’re going to want to look at are the System Controllers and Battery Monitors, usually they're not in the same.
A battery monitor most often includes an accumulating amp-hour meter, a voltmeter and an amp meter with a shunt. This unit is best placed in the kitchen or somewhere that it is in view all the time. In the end the most basic question you’ll always ask is… "What is the battery state of charge?" Because it determines whether you can watch a movie tonight or not… see? With a Battery Monitor you really just get to look… It usually provides no system programming functions. There are exceptions to this.
System Meter or System Controller is the brain of your system, this is where you program all the parameters of your system… the battery charge settings for the Inverter/Generator, sleep modes, Gen start etc. This unit goes right next to the Inverter and the Batteries. While it does give a little amount of information on the health of the system is usually can’t replace a Battery Monitor. So in the end you will probably need both, a System Controller near the Inverter and Batteries to do the programing and the Battery Monitor in your kitchen to tell you what is going on.