These articles all relate to the open-source charge controller project. We cover the hardware and the software and give a full design for a 12/24V DC 20A charge controller which can be used for solar, wind, hydro or pedal power applications.

Charge Controller Project – Overview

We have been wanting to design, build and supply an open-design, relatively inexpensive but fully functioned charge regulator for solar PV, wind, pedal and small hydro systems for a while now. The majority of off-grid renewable energy systems are based upon lead acid batteries. Lead-acid batteries need to be protected from over-charging by the renewable … more

Charge Controller Project – Microcontroller

The open-source charge controller project will be based upon a microcontroller. A micro-controller is basically a small computer. It can be programmed with code which will run when the device starts up. The control program will be programmed onto the microcontroller. Using a re-programmable microcontroller means we can upload different code to perform different functions. … more

Charge Controller Project – Power Switching

Within the open charge regulator we must control power, either to limit the power flowing into the battery or to control the power flowing to the dump load. This requires some kind of power switching. This article explains the different types o power switching available to us and the decision on which type of power … more

Charge Controller Project – Power Supply

Here we discuss options for providing power to the circuit itself. The input from the renewable energy source will be variable and the input voltage will vary. We need to provide power to the microcontroller ‘brains’ of the device. This requires 5V DC. Hence we need to efficiently step down the voltage from the input … more

Charge Controller Project – Voltage Measurement

Measuring voltage is required for the open charge controller project, as we use the voltage to measure the charging of the battery. Hence we need to be able to reliably and accurately measure voltage. I have written quite a bit before on voltage measurement. Here are the details on measuring voltage specifically for the open … more

Charge Controller Project – Heatsink

The open-source charge controller circuit contains a diode and a MOSFET, which could potentially have up to 20A flowing through them. In this case they will get hot and will eventually fail. We need to ensure that they will be kept within their specific working parameters by keeping them cool. This is done with a … more

Charge Controller Project – Hardware

This is an overview of the hardware including the overall design and the specifications used to calculate every component. We will also need to test all of the hardware to ensure it meets the specifications. This is part of the open-source charge controller project. … more

Charge Controller Project – Kit

Note (9/10/13): This is a work in progress and there are no kits available yet. Please watch this space or email us if you are interested. Here you can buy a kit of the open-source charge controller. This includes all parts and a pre-programmed microcontroller. Full instructions for making your kit are available here. If … more