Project Background and History :
In India most of the people are living in rural area where national grid transmission line is not reached till now.The existing electric grids are not capable of supplying the electricity need to those poor people.So renewable energy sources ( photo voltaic panels and wind-generators) are the best option.Solar power have the advantage of being less maintenance and pollution free.So I started to design a DIY solar charge controller to help poor people. The project was started on March-2014 from a simple Arduino based PWM Charge Controller and till now I am continuing to upgrade it.The current version is v-3 which is based on ARDUINO MPPT charge controller.It can charge a commonly used 12V lead acid battery from a solar panel.
Here is the links to my 3 Charge Controller Project
After making success in my earlier versions charge controller,now I am planning to make Version-4 Charge Controller. It will more advanced, greater capacity (up to 500 Watts ) and useful more potential applications.When the project complete, it should be useful for off grid electricity users, control of autonomous street lights and signs, and many other applications that need medium power levels and efficient reliable operation.
Ideas and Planning for the Version-4 Charge Controller :
1. Increase panel voltage rating to allow for panels with 60 cells (i.e up to 40 V, so- called "grid connect" panels);
2. Higher current rating, at least 20 amps and preferably 40 amps;
3. Metering current on the battery and load;
4. Improve design robustness to ensure external conditions do not cause any failures;
5. Design that allows multiple controllers to feed into a power distribution switchboard;
6. Optimal battery management for several different battery types, such as Lead Acid (several variants), NiFe, LiFePO4 etc.
7. Ability to control more than one load output – either to allow for greater capacity, or timing control of when the output is on or off.
8. Real time clock with date to enable time stamping of statistics and timer control of loads.
9. Operational configuration capability (buttons or via WiFi?);
10. Greater data collection to get illumination statistics, battery performance statistics, load statistics.
11. Higher battery voltage (to 24 or 48 V) and associated higher solar panel voltages;
12. Much higher panel voltage (to 150 V or so)
13. Multiple Load outputs regulated to close to 12 V
14. Panel safety and overload disconnect
Apart from the above features ,we are trying to ensure the following points
1. Focus on maximising efficiency
2. Fail-safe software or self-recovery features
3. MPPT algorithm refinements
You can find all the ongoing activities in the following link