Charge Controller

Introduction

A charge controller is an essential part of nearly all power systems that charge batteries, whether the power source is PV, wind, hydro, fuel, or utility grid. Its purpose is to keep your batteries properly fed and safe for the long term

The basic functions of a controller are quite simple. Charge controllers block reverse current and prevent battery overcharge. Some controllers also prevent battery over discharge, protect from electrical overload, and/or display battery status and the flow of power

    Hardware Interface Of Charge Controller

The following diagram shows the hardware interface of the PV Charge Controller

Front view of PV Charge Controller

Where

1. 1      Battery LED Indicator
2. 2    LCD Display
3. 3     Reset button
4. 4    Temperature Sensor  (Optional )
5. 5    .12V DC Load terminal with Low Voltage Disconnect/NIGHT-LIGHT mode
6. 6     12V Battery connection terminal
7. 7     PV Panel connection terminal
8. 8    Remote Signal Terminal (Optional )
9. 9   Side Door (open to access switches for setting)

   Connection of Charge Controller

The PV Charge Controller should be connected as follow

Connection of PV Charge Controller

This diagram illustrates the connectivity of a typical solar power kit, including a solar panel, a solar charge controller, a battery and the load (e.g. a light bulb). The solar panel connects to the controller through positive and negative leads, only creating a charging function when the controller is connected to a battery. The load is then responsible for the discharging function from the controller (if it is connectedto the controller)

In some rare cases, a solar panel can be connected directly to a battery, without a controller. This can be achieved if the nominal voltage of the panel is lower than 17-18V, and if the solar panel is a lot smaller than the charging battery e.g. a 10Wpanel charging a 100Ah battery