Autonomy is measured in days and uses, not by collecting equipment. The same water tank and battery may last a careful solo traveller a week or constrain a family after two days. The calculation starts with a realistic day.
Measure a typical day
For electricity, record the power and running time of every load: lights, pump, refrigerator, heater, phones, laptop and camera equipment. Convert the total into daily watt-hours, then add a margin for conversion losses and poor production days.
For water, separate drinking, cooking, washing-up and personal washing. Measure an actual day at home or on a weekend. The result is usually more reliable than an abstract estimate.
- Measured daily consumption
- Number of days without charging or filling
- A margin for season and weather
Size storage and charging together
The battery must cover useful consumption without exceeding the recommended discharge range for its chemistry. Solar production depends on season, angle, shade and panel cleanliness; rated power is never guaranteed output.
Use compatible charging paths where the installation allows: solar, alternator and mains. Protection devices, cable sizes, ventilation and isolation must be designed and installed by a competent person.
Extend autonomy through daily habits
The lightest equipment is what you do not need to carry. Simple level monitoring, careful washing, covered cooking and charging devices during available production reduce the reserves required.
Keep a separate emergency margin. Do not consume it simply to prolong a comfortable stop. When water or energy reaches that threshold, the route should already lead to a service point.
