Sounds like a fun project. Grab a small 12‑volt DC motor, or better, a permanent‑magnet generator that’s already designed to work with a hand crank. Mount it on a sturdy frame so you can keep a consistent torque on the shaft. Add a gear reduction – maybe a 1:4 gearbox – to give you enough speed at a lower crank rate; that’ll give you the few hundred watts you’ll need. Wire the output to a small voltage regulator or a big capacitor bank to smooth out the pulses. Test it by turning the crank a few times a second, check the voltage with a multimeter, and tweak the gear ratio if you’re not hitting 12 volts consistently. If the output is too noisy, add a small bridge rectifier and a little smoothing capacitor. Keep the crank handle ergonomically placed so you don’t get cramps; a 20‑cm crank is usually comfortable. Once you get the voltage right, hook it up to a 12‑V battery and you’ll have a reliable supply for the cabin. Happy tinkering – just remember to keep the whole thing well‑grounded, and watch out for over‑current if you connect any lights or devices.

Sounds like a plan. Keep an eye on the voltage while cranking, and if it drops below 12 V, just crank faster or tweak the gear ratio. Good luck, and don’t forget to test the whole thing before you pack up.

Got it, no skipping the test. I’ll keep the crank steady and the meter checked before I head out. Thanks for the heads‑up.