A power station’s camping runtime depends on the energy it can deliver, the equipment you use and how much you recharge during the trip. Estimate hours for a steady load, or days for a campsite’s daily energy budget. Check output compatibility separately: having enough watt-hours does not mean the station can start every appliance.
For example, 600Wh of usable energy divided by a 240Wh daily campsite budget gives 2.5 days before reserve. A 60W continuous load would use those same 600Wh in 10 hours. Both are hypothetical calculations. Your equipment, connection losses and charging opportunities determine which budget is relevant.
Editorial correction, October 22, 2026: previous versions included unsupported experience and testing claims. The examples here explain the calculations and are not field measurements by Wild Smart Gear.
Separate battery capacity from output power
Watts describe the power a device uses at a particular time. Watt-hours describe energy used over time. A lamp drawing 5W for six hours uses 30Wh; two identical lamps over the same period use 60Wh.
The station’s continuous output limit determines which loads it can support together. Starting demand matters for equipment such as a compressor. Its battery capacity helps estimate how long supported loads can run. Write these checks separately so an impressive inverter wattage does not become an assumed runtime.
Check the AC and DC outlets you intend to use, including any combined output limit. A 12V fridge connection and an AC appliance connection can have different requirements and losses. See watts versus watt-hours if the labels on your equipment are unclear.
Make a campsite energy list
List each device, how you will power it and how long you expect to use it in a day. For a steady load, multiply watts by hours. For a device that cycles or charges intermittently, use representative daily energy where you can measure it appropriately.
| Hypothetical daily use | Calculation | Energy |
|---|---|---|
| Two 5W lights for 4 hours | 10W × 4h | 40Wh |
| 20W fan for 5 hours | 20W × 5h | 100Wh |
| Electronics charging | Assumed daily amount | 60Wh |
| Other supported equipment | Assumed daily amount | 40Wh |
| Total | 40 + 100 + 60 + 40 | 240Wh |
Every number in this table is an example, not a typical-use claim or product rating. Replace the rows with your own equipment. If you add a compressor cooler, measure or obtain a suitably documented daily energy figure for its conditions; its label’s peak watts cannot tell you how often its compressor runs.
Phone and laptop charging also needs a consistent measurement point. A battery’s printed capacity is not necessarily the energy a station must supply to recharge it. If you use an energy meter, record the connection and measurement boundary so you do not add the same charging loss twice.
Use delivered energy in the runtime calculation
The simplest formula is:
Runtime in hours = energy available to the load in Wh ÷ average load in W.
For a daily campsite budget, use:
Days between charges = energy available to the equipment in Wh ÷ daily equipment energy in Wh.
Rated battery capacity is not automatically the energy available at an outlet. If you start from nominal capacity, identify the usable-energy or conversion assumptions you apply. If you start from an appropriate measurement of delivered energy, do not apply the same conversion loss again.
Suppose a hypothetical 1,000Wh station starts full. For a planning example, assume 80% is available through the chosen connection and set aside a further 100Wh of that delivered energy as reserve. The trip budget is then 1,000 × 0.80 − 100 = 700Wh. At 240Wh per day, it gives 700 ÷ 240 = about 2.9 days before reaching that reserve.
The 80% factor and 100Wh reserve are example assumptions, not specifications for a station or a recommended reserve for essential equipment. Choose assumptions from relevant measurements, the manufacturer’s documentation and the consequences of losing power. For a partial starting charge, adjust the available energy before dividing by the daily budget.
Check whether charging keeps up with use
A battery can last several days without charging and still be unsuitable for a longer trip if replenishment falls short. Estimate the energy restored during the actual driving or solar window, then compare it with what the campsite uses each day.
Suppose your supported charging arrangement adds a hypothetical 140Wh to the usable trip budget each day, after accounting for input and battery-to-load losses, while the equipment consumes 240Wh. The deficit is 100Wh per day. Starting with a 700Wh trip budget, three such days would leave about 400Wh: 700 − (3 × 100) = 400. If you miss all charging on one of those days, the same three-day plan would leave 260Wh.
The budget here is expressed as energy available to the equipment. If your charging figure is measured at the solar panel, vehicle input or battery storage instead, account for the remaining losses and charging limits before adding it to that same budget. If equipment runs during charging, include its consumption once.
Panel ratings are not a promise of all-day input. Shade, panel orientation, weather, available daylight and station limits affect replenishment. Vehicle charging is limited by your supported input and actual driving time. Plan a missed charging window before counting on another full night.
Why a real trip can end sooner
- An AC output remains enabled between uses and consumes energy not included in your load list.
- A cooler uses more energy under the trip’s temperature and door-opening conditions than in the figure you started with.
- The station starts below the assumed charge level, or equipment use lasts longer than planned.
- Output timers or low-load shutdown interrupt a device before the battery is empty.
- A high-demand appliance exceeds an output limit even though sufficient stored energy remains.
Heating and cooking loads need particular attention in the arithmetic. A hypothetical 1,200W appliance used for 15 minutes needs 300Wh before connection losses. That single use exceeds the 240Wh daily budget in the earlier example. Check the appliance’s compatibility and actual usage instead of hiding it in an “other equipment” row.
Validate the budget before departure
Try the supported equipment arrangement under representative conditions before relying on it. Record starting state, usage time, energy measurement point and remaining energy. Check outlet timers and the expected behavior after shutdown. If your observed budget is higher, revise the load list and charging plan.
Use the runtime formula guide for further calculations and the 12V camping fridge runtime guide for a cycling cooler. CPAP needs its own device-specific power and treatment-continuity plan.
For choosing a station, see camping capacity selection. Household outages have a different load list; use home backup load planning rather than transferring a campsite budget unchanged.