I'm looking to add a second 150W solar panel to my caravan, where I already have one installed. I've recently upgraded my solar controller to a Victron 100/30 and replaced my old lead-acid battery with an Ecotree 100Ah lithium battery. The existing wiring looks like 2.5mm (12 gauge), and I plan to use MC4 parallel couplers to connect the new panel in parallel with the existing one. My main concern is whether the 12 gauge wire is sufficient for carrying up to 300W of power, or should I upgrade to 10 gauge wire? Any advice would be appreciated!
1 Answer
You've got it right! Your 12 AWG wire should handle the current just fine with two panels connected. Typically, 12 AWG can carry around 20A, and since each 150W panel might push around 6A, you won’t be exceeding the capacity. Just keep an eye on shading; if a panel gets shaded, a parallel connection would definitely help. That way, you can still get power from the panel in sunlight while avoiding issues with the one that's shaded.
Thanks a lot! I was worried about overheating the wire, especially in full sun, but it sounds like I'm good to go. I’ll stick with the MC4 connectors and splice into my existing setup. I'm glad you mentioned parallel wiring too; with my caravan's roof and tree shade issues, it seems like the best choice.