BUYING GUIDE

Off-Grid Living: Sizing a Solar and Battery Setup for Full-Time Use

Weekend camping power and full-time off-grid power are two different problems. A weekend trip just needs to last until you're back near an outlet. Full-time off-grid living needs a system that sustains itself indefinitely, which changes almost every part of how you size it.

Start from daily usage, not a single trip

Instead of asking "how long will this last," full-time off-grid sizing starts with "how much do I use in an average day," since that's the number your solar input needs to match, day after day, not just once. Add up daily draw from lighting, device charging, a fridge if you're running one, and any tools or medical equipment, then treat that as your baseline rather than a one-time capacity target.

Solar has to outpace usage, not just cover it

A weekend setup can run a battery down and recharge it "eventually." Full-time living needs solar input that reliably exceeds daily usage, including on shorter or cloudier days, or the system slowly drains over a stretch of bad weather. This usually means sizing your panel capacity with a real margin above your calculated daily draw, not the bare minimum.

Battery capacity as a buffer, not just storage

• Weekend trip: battery capacity just needs to outlast the trip.
• Full-time off-grid: battery capacity needs to buffer several consecutive low-sun days, acting as insurance against a stretch of bad weather rather than just overnight storage.
• Consider a second unit or extra battery once you're relying on the system daily rather than occasionally, redundancy matters more when there's no backup plan waiting at home.

Plan for the worst week, not the average one

An average sunny week will make almost any setup look adequate. The system that actually works is the one sized for your worst realistic stretch, several overcast days in a row, not the best-case scenario. If your calculations only work on clear days, the setup isn't sized for full-time use yet.

Working out your daily draw? Our watt-hour guide is the place to start, and our Buying Guide covers capacity by use case more broadly.