Free calculator
Portable Power Station Size Calculator
List the devices you want to run, how long each runs per day and for how many days. We’ll suggest a capacity, inverter size and solar input.
| Device | Watts | Hours/day | Qty | AC? | |
|---|---|---|---|---|---|
Typical: 3–6
Estimated results — estimates only, real-world results vary.
Recommended capacity
512 Wh
Minimum 396 Wh needed
Inverter output
≥ 100 W
80 W if everything runs at once, +25%
Daily energy use
310 Wh
356 Wh from the battery incl. losses
Solar to refill daily
≈ 150 W
at 4 peak sun hours
How it’s calculated
- Daily load (Wh) = Σ watts × hours × quantity
- Battery energy needed per day = AC load ÷ inverter efficiency + DC load ÷ 0.95
- Required capacity (Wh) = daily battery energy × days ÷ usable fraction
- Inverter (W) ≥ total running watts × 1.25
- Solar (W) ≈ daily battery energy ÷ (peak sun hours × 0.75)
Assumptions
- Inverter efficiency defaults to 85% for AC devices; USB/12 V devices are assumed 95% efficient.
- Usable capacity defaults to 90% of the rated Wh.
- Assumes all devices could run at the same time when sizing the inverter, with a 25% margin. Motors and compressors can surge 2–3× on start-up — check surge ratings.
- Solar estimate assumes panels deliver about 75% of their rating in real conditions.
- For fridges, use average watts (or watts × duty cycle), not the peak rating.
Estimates only. Results are approximations based on the assumptions above. Always check your manufacturer’s specifications and safety guidance.
Capacity vs output
Capacity (Wh) decides how long things run; inverter output (W) decides what you can run at once. You need enough of both.
Charging an e-bike from a power station
An e-bike charger typically draws 80–200 W. A 672 Wh battery needs roughly 800 Wh from the station once inverter losses are included.
Frequently asked questions
Can a power station charge my e-bike?
Yes, if its AC output exceeds your charger’s wattage. Budget about 1.2× your e-bike battery’s Wh in station capacity per full charge.
What does LiFePO4 mean?
Lithium iron phosphate — a battery chemistry common in power stations. It is heavier than NMC but lasts thousands of cycles and is very stable.