Enter your battery capacity and connected devices to estimate usable runtime and recharge time from a solar panel, accounting for depth-of-discharge and inverter losses.
Use this before an off-grid trip, power outage, or van-life setup to check whether a portable power station and solar panel combination can actually sustain your planned devices.
Unlike a simple “battery Wh divided by device watts” estimate, this calculator subtracts realistic depth-of-discharge and inverter losses before computing runtime, and separately estimates real-world solar recharge time rather than assuming the panel’s full rated output.
Usable battery energy is the rated Wh capacity reduced by both the usable depth-of-discharge percentage and the inverter’s conversion efficiency.
Daily load is the sum of each connected device’s wattage multiplied by its hours of use per day.
Runtime in days is usable energy divided by daily load, while recharge time is the battery capacity divided by the solar panel’s effective wattage after accounting for real-world recharge efficiency.
Rated Wh figures assume 100% depth of discharge and a perfect inverter. In practice, most power stations reserve some charge to protect battery health, and the DC-to-AC inverter loses some energy as heat, so real-world usable energy is lower than the sticker number.
A larger panel delivers more watts under the same sunlight, so it refills the battery faster. Recharge time also depends heavily on panel angle, cloud cover, and time of day, which is why the recharge efficiency percentage matters as much as the panel’s rated wattage.
A mini fridge’s compressor draws several times its running watts for a brief moment on startup. A power station or inverter sized only for the running watts can fail to start the compressor even though it can sustain it once running.
Input
Battery 1000 Wh, 90% usable DoD, 88% inverter efficiency, mini fridge (60W×24h) + laptop (65W×4h), 200W solar panel at 70% recharge efficiency.
Output
Usable capacity: 792 Wh. Daily load: 1,700 Wh/day. Runtime: about 0.47 days (~11 hours). Recharge time: about 7.1 hours of sun.
Usable energy is 1000 Wh reduced to 792 Wh after depth-of-discharge and inverter losses. The fridge and laptop together draw 1,700 Wh/day, so the battery lasts under half a day without sun. A 200W panel at 70% real-world efficiency recharges the full 1000 Wh battery in about 7.1 hours.
How long does your text take to read?
utilityTurn text into fill‑in‑the‑blank exercises.
utilityTwitter-weighted character counter with thread split.
utilityTitle + description pixel-width validator with SERP preview.