How this calculation works
- Energy required = capacity × (target − starting charge). Capacity is a manufacturer spec; charge levels are your inputs.
- Connected solar = panel watts × number of panels. User input.
- Usable input = the smaller of connected solar and the station's maximum solar input. Manufacturer spec.
- Effective input = usable input × solar yield, minus any load running while charging. Yield is a planning assumption.
- Peak-sun-hours = energy required ÷ effective input; divided by your peak sun hours per day gives approximate sunny days. Calculated estimate.
Why real charging varies
Actual solar charging changes with clouds, season, latitude, panel orientation and angle, temperature, shade, cable losses, MPPT/charge-controller behavior, battery temperature, and the slower charging most batteries use near full. Treat this result as an estimate, not a guaranteed charging time.
Wattage isn't compatibility. Your station's manual lists solar input voltage and current limits. Panels wired in series add voltage; in parallel they add current. Stay inside both limits and use connectors the manufacturer approves.
Want to know how long the charged battery will last? Use the Power Station Runtime Calculator.
Solar recharge FAQ
›How long does a 200W solar panel take to charge a power station?
Divide the energy needed by the panel's real-world output. Assuming 75% yield, a 200 W panel delivers about 150 W in full sun, so refilling 800 Wh takes roughly 5.3 peak-sun-hours — often more than one day of real sunshine.
›Why doesn't a 200W panel always produce 200W?
Panel ratings are measured under standard laboratory conditions. Heat, sun angle, haze, dirt, shade, cable losses and the charge controller all reduce output in practice. The yield factor in this calculator is an adjustable planning assumption for those losses.
›What are peak sun hours?
A peak sun hour is the solar energy equal to one hour of full-strength sunlight (1,000 W per square meter). A day with 5 peak sun hours might have 12 hours of daylight, but only delivers the energy of 5 full-strength hours. Peak sun hours are not hours of daylight.
›Can I connect more solar panels than my power station's solar-input rating?
Extra panel wattage can't push more power than the station's maximum solar input — this calculator caps it there. More importantly, you must stay within the station's input voltage and current limits; exceeding them can damage the station. Check the manual before connecting panels in series or parallel.
›Can I use appliances while charging from solar?
Many stations allow it (pass-through charging), but whatever the appliance draws comes out of the solar input first. If the load is equal to or greater than the solar input, the battery may not gain charge. Check your station's manual for pass-through support.