Introduction to 12V System Configurations

When setting up a 12V system, ensuring that charge controllers and inverters are connected correctly is crucial for optimal performance and battery health. In this guide, we will explore how to connect multiple charge controllers to the same battery bank and inverter, ensuring that the setup is both functional and efficient.

Connecting Batteries in a 12V System

In a 12V system, batteries can be connected in series and/or parallel to achieve the desired voltage and capacity. When connecting batteries, it is important to connect all positive terminals together and all negative terminals together. Alternatively, you can connect each battery individually to the same bus bar. This provides flexibility and ensures that each battery can be managed independently or collaboratively with other sources of power.

Connecting Multiple Charge Controllers to a Battery Bank

Multiple charge controllers can be connected to the same battery bank, provided that the voltage generated by these controllers is within the acceptable limits of the battery. Voltage regulation is critical, as it prevents the battery from being overcharged. Various sources of electricity, such as a car alternator, hydro power, wind mill, or an AC/DC charger, can be connected to the same bus bar. All generating sources should be voltage regulated and designed for the type of battery they are supplying.

Voltage Regulation and Priority

It is essential to ensure that the voltage from each generator does not exceed the maximum allowable voltage for the battery. When multiple sources are connected, the highest voltage source will supply power first, but measuring the voltage will reveal that each source contributes to the overall current being consumed. The contribution of each charge controller depends on the calibration and programming set by the user. Generally, calibrated charge controllers will contribute equally, supplying about 50-50 current. Unaltered controllers may idle before others, but the total generation is already maximized, and additional current is unnecessary.

Connecting Charge Controllers and Inverters to the Battery Bank

To connect two or more charge controllers to the same battery bank, follow these steps:

Connect the output and negative terminal of the first charge controller to the battery bank. Connect the output and negative terminal of the second charge controller to the battery bank. Connect the inverter's input and negative terminal to the battery bank. Connect the first solar array to the input of the first charge controller. Connect the second solar array to the input of the first charge controller.

Note: The wiring connections of the two solar arrays should not be connected to each other, only to the respective charge controller input.

Final Considerations

If you need to adjust the priority of a generating source, you can do so by changing the settings on the charge controller. For example, lowering the maximum bulk voltage on one controller will cause it to enter float charging mode earlier than the others, reducing its contribution to the total current.