What wattage portable solar panel do I need for a power station?

It depends on your battery capacity and how fast you want to recharge. A 100W panel is fine for small power banks and trickle-charging 12V batteries, 200W is the popular all-rounder for mid-size power stations, and 400W blankets or suitcases suit large stations or RV setups where you want a full recharge in a day. Note that real-world output is typically below the rated wattage because of sun angle, heat, and partial shade.