Wattstanding

Calculator

Solar recharge time calculator for power stations

Pick a power station or enter its capacity, then your panels and a sun-hours figure. We show the energy per day and the days to refill, region by region.

Gulf Coast about 5; Northeast about 4; winter is lower
Panels beyond this are not used

The formula

Wattstanding calculationEnergy per day (Wh) = panel watts × 0.75 × peak sun hours. Days to refill = capacity ÷ energy per day. The 0.75 covers heat, angle and cable losses.
Practical notePeak sun hours are approximate annual averages by region. A cloudy week, winter sun or partial shade can cut output by half or more. Always check the station's solar input voltage and current limits before connecting panels.

Questions

Can I connect more panel watts than the station's solar input limit?
The station will only use what its input allows, and exceeding its voltage or current limit can damage it. Follow the maker's limits.