In just one day, you’ll learn how to design, build, and troubleshoot a simple solar charger that costs less than $1 in parts — yet reliably charges a 3.7 V Li-ion cell from a 6 V solar panel. Perfect for hobbyists, educators, and community trainers, this workshop blends theory with hands-on practice so you leave not only with your own working charger, but also the confidence to teach others.

What You’ll Do:

• Understand the Basics – Learn the fundamentals of solar panel operation, Li-ion battery characteristics, safe charging, and why voltage regulation matters.

• Circuit Deep Dive – Explore how the LM393 comparator and TL431 shunt regulator work together to protect the battery from overcharge.

• Hands-on Build – Assemble your own charger using common, low-cost components that can be sourced anywhere.

• Outdoor Testing – Connect to a 6 V panel, measure charge performance, and observe real-time behavior under varying sunlight.

• Troubleshooting Skills – Identify common issues such as undercharging, overheating, and incorrect cutoff, and learn quick fixes.

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Takeaways:

• Your own working $1 solar charger circuit.

• Practical skills in solar energy and battery charging.

• Circuit diagrams, BOM (bill of materials), and step-by-step teaching guide for replication.

No prior electronics experience required. If you can use a soldering iron and read a simple diagram, you can master this in a day — and pass it on to others.