Ladies & Gentlemen welcome back once more. Following on from low-voltage solar systems and small-scale setups, this blog focuses on the technical side of solar energy how voltage, current, and capacity interact, and what it means when you're building real-world solar projects for DC devices or considering AC alternatives. These aren’t just academic principles they’re practical tools that anyone working with solar power needs to understand to build reliable and safe energy systems.

Series vs Parallel: How You Wire Matters

When connecting solar panels or batteries, series and parallel configurations produce very different results: Series Connection increases voltage but keeps the amperage the same. Example: Two 12V panels in series = 24V system. Parallel Connection keeps voltage the same but increases amperage. Example: Two 12V panels in parallel = 12V with double the current. This choice affects everything from charge controller compatibility to cable thickness and system safety. For small DC systems, you’ll often run parallel connections to increase power flow at the same voltage. For larger or more demanding systems (especially AC conversions), series connections become essential.

AC vs DC: What You Need to Know

DC (Direct Current) is what your solar panels produce natively. It’s perfect for battery charging, LED lighting, and small appliances. AC (Alternating Current) is what powers your home. To use solar for AC appliances, you’ll need an inverter to convert the DC power into 230V AC (in the UK). Why this matters: Every conversion introduces losses. Using solar for DC directly is far more efficient ideal for garden lights, USB devices, or low-voltage fans. AC setups require more complex gear (inverters, fuses, breakers) and are better for large-scale energy applications.

Working Out Charging Times: The Basic Formula

To calculate how long it will take to charge a battery using solar, you need to understand Watts = Volts × Amps, and Amp-Hours = Energy Storage.

Let’s run a basic example:

A 12V, 10Ah battery stores 120Wh of energy.

You use a 12V panel producing 2A in full sunlight.

That gives you 24W of power (12V × 2A).

Charging time = 120Wh ÷ 24W = 5 hours (in ideal sunlight).

Of course, real-world conditions like cloud cover and panel angle will increase the actual charge time. But this equation gives you a working baseline for planning.

Why This Matters in the Garden and Beyond

In my own setups whether powering solar garden lights, charging battery banks, or running sensors understanding these electrical basics helped me avoid underpowered systems or battery drain. With DC systems, it’s easy to scale slowly and learn hands-on. When stepping up to AC systems or high-power DC circuits, understanding series, parallel, and current flow becomes crucial to avoid short circuits, inefficient design, or battery damage.

Conclusion: From Curiosity to Competence

What started with a small solar panel powering a fan has grown into a deeper, hands-on understanding of electrical theory and sustainable design. Knowing the difference between volts and amps, how battery storage works, and why your wiring method matters makes all the difference in designing a safe, effective system. This second blog closes the loop on the what and how of solar energy systems. But the journey doesn’t end here. In the next and final chapter of this series, I’ll be pulling it all together showing how to design a complete solar setup from panel to device, integrating storage, monitoring, and controls to create a self-sustaining energy solution.

This one has been a intresting exploration Ladies and Gentlemen So until the next time... Take care.

Michael “Druid” Thomas
Lunacare Cymru | Media - Blog