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Wiring a solar panel via a solar charge controller

Solar charge controllers are extremely simple to wire. Most only require four connections. Two wires  - positive and negative - run from the solar panel to the charge controller, and another two wires run from the charge controller to the battery bank. That's it!

Solar charging system with solar controller - charging 12V battery banks

1) Connect the Controller to the Battery

The cable from the charge controller to the battery should be kept short, and needs to have sufficient cross-section to avoid voltage drop. Voltage drop not only wastes power by heating up the cables, but prevents the charge controller sensing the battery voltage correctly.

We always recommend putting a fuse in the positive line between the charge controller and the battery. That way if you make a mistake while wiring, or if a wire subsequently comes loose, you don't run the risk of short circuiting the battery bank.

2) Connect the PV Panel cables to the Controller

Solar panels are often supplied with short lengths of wire coming from the junction box on the back, terminated in connectors that are designed specifically for solar panels. The most common type is the 'MC4' connector, made by Multi-Contact. We sell compatible cable and connectors so that you can bring these cables inside to the solar regulator. You should use a good quality abrasion and UV-resistant cable for the outdoor wiring. 'PV cable' is sold for exactly this task, and has two layers of insulation, including a very tough outer sheath.

An EPEVER TRIRON MPPT controller with PV inputs on the left, battery output terminals in the middle and load terminals on the right. This model also handily has USB outputs for charging phones from 5V.

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