Off-grid wiring diagram (battery)

As a battery is charging, the voltage of it will rise to their point of over-charge. The over-charge occurs when the input voltage exceeds the battery capacity. For example, a 12v battery can easily absorb the current between 14.5v and 15v. Beyond this threshold, the damage may occur to your batteries and to the various devices that are connected. This is where the use of a 'dump load' becomes essential. A 'dump load' is a device capable of high electricity consumption. Thus, when the batteries have reached the point of over-charging, the 'dump load' will activate and 'burn' the surplus. A 'dump load' is already included in the WW and WM charge controllers. If you use a SCS wind turbine, you will have to install a 'dump load' to fully secure your system.

For the solar panels, you can work the same way by wiring them directly to your batteries and protec them against over-charging using a load diversion controller. On the other hand, in a solar installation, you can replace the diversion devices by a simple PWM or MPPT charge controller. The difference between solar and wind power is that solar panels can be simply disconnected from the batteries, without dammaging the power source. With a PWM controller, when the batteries are full, the solar panels are immediatly disconnected from the batteries. That way, you don't need any diversion controller or 'dump load' to burn the over-current. The MPPT controller is the same thing as a PWM controller, but with a maximum power tracking device. In other words, a MPPT controller will provide you about 30% more current than a PWM one.

The quality of the battery plays an important role in the effectiveness of an electrical system. You can use 12v car batteries, for against, their ability and their lifespan is limited. The deep cycle batteries are the best for alternative energies. However, batteries of 2v and 6v will undoubtedly offer the highest storage performances. Several appliances, including light bulbs, heaters, etc.. may already be connected directly to your batteries. A battery pack with a capacity of 5000 watts will be able to operate devices using 2500 watts for two hours. The same batteries will operate 10 000 watts appliances for 30 minutes. That is why it is important to measure our electricity needs.

To use electric appliances running on AC 110v or 220v, you will use an inverter. This device has the dual task of reversing the current (DC) batteries into alternating current (AC), but also to raise or lower the voltage supplied by batteries. Depending on the configuration of your electrical devices, the inverter will provide you with 110v or 220v current. Again, it is necessary to calculate and dertermine your electricity needs. For example, if you never use more than 1,000 watts simultaneously, a 1000 to 1500 watts inverter will be sufficient. In contrast, if a 1000 watts unit works regularly, it would be preferable to provide an inverter capable of providing 1500 to 2500 watts.