The Solar Power Expert Blog

Archive for the 'Charge Controller' Category

These are all posts related to my work with the Free Charge Controller project ( )

Free Charge Controller Kit – Part 2 – Preparing to Assemble the Power Circuitry

Thursday, March 15th, 2012

This is the second part of a multipart series of articles describing how I constructed the v4 Free Charge Controller kit from Jameco.

Testing the Solar Charge Controller Schematic

Friday, October 21st, 2011

I was finally able to find some time to test my step down converter prototype. The results showed an efficiency of 71%. That’s not bad for a first prototype! Below, I’ll show all the test data, schematics, pictures, and some of the ideas I’ve come up with for improving the design.

Step Down Converter Prototype Parts

Tuesday, October 4th, 2011

I finally got some time to put together a prototype of my proposed dual voltage converter. I wrestled with myself over how to wind the converter transformer. Depending on how I wind it, I could create a 48v battery charger for my electric bicycle, or I could step it down to charge a 12 volt battery. By carefully selecting the number of turns on the transformer, you should be able to make several different types of voltage converters from this circuit.

Manufacturability of the New Free Charge Controller Design

Sunday, September 11th, 2011

My proposal for the DIY Dual Voltage Converter design for the Free Charge Controller project generated some good feedback. This post is a copy of the one of the replies and focuses on the manufacturability of the two designs and some of the different aspects of the two designs.

A DIY Dual Voltage Converter – Turning The Solar Charge Controller Circuit On Its Head

Tuesday, September 6th, 2011

There has been some discussion lately on the Free Charge Controller mailing list about the future direction of the project. The main points of the discussion have centered around how to incorporate the Arduino into the project and how to get hardware into the hands of interested members.

An Open Source High Speed Data Logger

Tuesday, August 23rd, 2011

I needed to run a test at work that required a high speed data logger. Since we didn’t have the budget to purchase one, I decided I’d give a shot at quickly building one out of a Maple and this SD Card Shield from Seeed Studios.

04/21/2011 Update on Free Charge Controller

Thursday, April 21st, 2011

A hacker of the free charge controller asked me about the difference between version 2 and 3. I answer her question in this post.

Update on v3 Free Charge Controller Board 3/24/2011

Thursday, March 24th, 2011

Now that the sun is starting to poke its head out more often, I’m feeling more inclined to jump back into the Free Charge Controller project. I managed to populate and test the two v3 prototypes I had made up. I can’t remember if I sent an email to the mailing list or not about that or not.