What Size Portable Power Station Do I Need? (Simple Wh Math + Examples)
Quick verdict
Pick a station whose continuous output (W) exceeds everything you'll run at once, and whose capacity (Wh) covers watts × hours ÷ 0.85. For typical outage essentials (400–900 Wh/day), a ~1,000 Wh station is the usual starting point.
Step 1: Know the two numbers that matter
- Output (watts, W): the maximum load at one time. Example: the Jackery Explorer 1000 v2 is rated 1,500 W continuous / 3,000 W surge; the EcoFlow DELTA 2 is rated 1,800 W continuous / 2,700 W surge.
- Capacity (watt-hours, Wh): the stored energy. The two units above are 1,070 Wh and 1,024 Wh respectively.
Step 2: List your devices
Find the watts on each device's label or manual (don't guess — labels vary a lot). Write down how many hours per day each will run.
Step 3: Do the math
Required Wh ≈ Σ(device watts × hours) ÷ 0.85
The 0.85 factor is a conservative allowance for inverter losses; real-world efficiency varies by model and load.
Worked example (illustrative wattages — use your own labels)
| Device | Watts (from label) | Hours | Wh |
|---|---|---|---|
| Device A | 60 | 8 | 480 |
| Device B | 10 | 5 | 50 |
| Device C | 40 | 3 | 120 |
| Total | 110 W peak | 650 Wh |
650 ÷ 0.85 ≈ 765 Wh needed → a ~1,000 Wh class station gives headroom.
Runtime from a given station
Runtime (h) ≈ capacity Wh × 0.85 ÷ load W. A 1,070 Wh station on a steady 100 W load: 1,070 × 0.85 ÷ 100 ≈ 9 hours.
Size tiers at a glance
| Your total daily Wh | Class to look at | Notes |
|---|---|---|
| Under 400 Wh | 300–500 Wh | Phones, laptops, lights, fans |
| 400–900 Wh | ~1,000 Wh | Typical outage essentials, weekend camping |
| 900–1,800 Wh | 1,000 Wh + expansion, or 2,000 Wh | DELTA 2 accepts an extra battery (up to 3,072 Wh per EcoFlow); Jackery states the 1000 v2 does not expand |
| 1,800 Wh+ | 2,000–3,000 Wh+ or solar recharging | Multi-day outages |
Our picks in the ~1 kWh class
Jackery Explorer 1000 v2
- 1,070 Wh LiFePO4 battery
- 1,500 W continuous / 3,000 W surge
- 3 AC outlets
- Not expandable
- ~23.8 lb · 3+2-year warranty
EcoFlow DELTA 2
- 1,024 Wh LFP battery
- 1,800 W continuous / 2,700 W surge
- 6 AC outlets
- Expandable to 3,072 Wh
- ~27 lb · 5-year warranty
See the full head-to-head: EcoFlow DELTA 2 vs Jackery Explorer 1000 v2. Wondering about battery types? Read LiFePO4 vs lithium-ion.
Frequently asked questions
How many watt-hours do I need?
Add up (watts × hours) for every device you will run, then divide by about 0.85 to allow for inverter and conversion losses.
What is the difference between W and Wh?
Watts (W) is how much power the station can deliver at one moment; watt-hours (Wh) is how much energy is stored. You need enough of both.
Does surge rating matter?
Yes for motors and compressors (fridges, pumps), which briefly draw more than their running watts at start-up. Check the station's surge/peak figure.
Sources
- Jackery Explorer 1000 v2 product page: https://www.jackery.com/products/jackery-explorer-1000-v2
- Jackery AU product page (no capacity expansion): https://au.jackery.com/products/explorer-1000-v2-portable-power-station
- EcoFlow DELTA 2 product page: https://us.ecoflow.com/products/delta-2-portable-power-station