How Long Does a 500W Portable Power Station Last? (+ Data Tables)
ZacharyWilliamShort answer: it depends on battery capacity (Wh), your device's power draw (W), and whether you use AC or DC outputs. Below you'll find clear formulas, worked examples, and large data tables for fast planning.
- 500W load on AC: about 0h 51m (≈0.85 h)
- 100W TV on AC: about 4h 15m
- 60W laptop/CPAP on AC: about 7h 5m
- 10W router/phone on DC: about 47h 30m
Assumes 85% inverter efficiency for AC and 95% regulator efficiency for DC. Real-world times vary with temperature, age, and device behavior.
What “500W” really means
“500W” is the inverter output rating—the maximum continuous power the station can supply to AC devices at once. It is not the battery size. The battery's energy is measured in watt-hours (Wh). A 500W unit might house a 300–700Wh battery, which explains why runtime varies widely.
Runtime formula
For quick planning, use 0.85 efficiency for AC outlets and 0.95 for DC/USB ports. Many power stations let you use nearly all of the rated Wh, but in practice background draw and protection margins reduce it slightly.
Runtime tables (AC)
Use these to estimate how long different battery sizes last with common AC loads. Numbers assume 85% inverter efficiency.
| Capacity (Wh) | 30W | 50W | 60W | 80W | 100W | 120W | 150W | 200W | 300W | 500W |
|---|---|---|---|---|---|---|---|---|---|---|
| 300 | 8.50 | 5.10 | 4.25 | 3.19 | 2.55 | 2.12 | 1.70 | 1.27 | 0.85 | 0.51 |
| 400 | 11.33 | 6.80 | 5.67 | 4.25 | 3.40 | 2.83 | 2.27 | 1.70 | 1.13 | 0.68 |
| 500 | 14.17 | 8.50 | 7.08 | 5.31 | 4.25 | 3.54 | 2.83 | 2.12 | 1.42 | 0.85 |
| 512 | 14.51 | 8.70 | 7.25 | 5.44 | 4.35 | 3.63 | 2.90 | 2.18 | 1.45 | 0.87 |
| 600 | 17.00 | 10.20 | 8.50 | 6.38 | 5.10 | 4.25 | 3.40 | 2.55 | 1.70 | 1.02 |
| 700 | 19.83 | 11.90 | 9.92 | 7.44 | 5.95 | 4.96 | 3.97 | 2.98 | 1.98 | 1.19 |
Tip: If a device cycles on/off (like a fridge), use its average draw over time.
Runtime tables (DC)
When you can, power low-voltage gear from DC/USB. It avoids inverter losses and extends runtime. The table below assumes 95% regulator efficiency.
| Capacity (Wh) | 10W | 20W | 30W | 50W | 60W | 100W | 150W | 200W |
|---|---|---|---|---|---|---|---|---|
| 300 | 30.00 | 15.00 | 9.50 | 5.70 | 4.75 | 2.85 | 1.90 | 1.42 |
| 400 | 40.00 | 20.00 | 12.67 | 7.60 | 6.33 | 3.80 | 2.53 | 1.90 |
| 500 | 50.00 | 25.00 | 15.83 | 9.50 | 7.92 | 4.75 | 3.17 | 2.38 |
| 512 | 51.20 | 25.60 | 16.21 | 9.73 | 8.11 | 4.86 | 3.24 | 2.43 |
| 600 | 60.00 | 30.00 | 19.00 | 11.40 | 9.50 | 5.70 | 3.80 | 2.85 |
| 700 | 70.00 | 35.00 | 22.17 | 13.30 | 11.08 | 6.65 | 4.43 | 3.33 |
Real-world examples
Here are ballpark runtimes for a 500Wh battery. If your station has 300Wh or 600Wh, multiply results by 0.6 or 1.2 respectively.
| Device | Power (W) | 500Wh on AC (h) | 500Wh on DC (h) |
|---|---|---|---|
| Smartphone (USB-C 10W) | 10 | 42.50 | 47.50 |
| Wi-Fi router (DC 10W) | 10 | 42.50 | 47.50 |
| LED light string (DC 5W) | 5 | 85.00 | 95.00 |
| Laptop 13–15" (AC 60W) | 60 | 7.08 | 7.92 |
| CPAP no humidifier (AC 40W) | 40 | 10.62 | 11.88 |
| CPAP with humidifier (AC 60W) | 60 | 7.08 | 7.92 |
| 32" LED TV (AC 50W) | 50 | 8.50 | 9.50 |
| 55" LED TV (AC 100W) | 100 | 4.25 | 4.75 |
| Gaming console (AC 120W) | 120 | 3.54 | 3.96 |
| Mini fridge (average AC 60W) | 60 | 7.08 | 7.92 |
| Box fan (AC 40W) | 40 | 10.62 | 11.88 |
| Projector (AC 150W) | 150 | 2.83 | 3.17 |
| Blender (AC 300W intermittent) | 300 | 1.42 | 1.58 |
| Power drill (AC 500W intermittent) | 500 | 0.85 | 0.95 |
For CPAP machines, turning off the humidifier/heated tube dramatically reduces power draw and extends runtime.
Charging time estimates
Actual charge time depends on the station’s max input, charger efficiency, and the last 10–15% “taper”. The table uses a 10% overhead factor.
| Input (W) | Time (h) |
|---|---|
| 60.00 | 9.17 |
| 100.00 | 5.50 |
| 120.00 | 4.58 |
| 200.00 | 2.75 |
| 300.00 | 1.83 |
Solar times assume ideal sun and MPPT tracking. Expect longer times with clouds, heat, or sub-optimal panel angles.
Battery lifespan & health
Cycle life (typical)
- LiFePO₄: ~3,000–4,000 cycles to ~80% capacity
- NMC: ~500–1,000 cycles to ~80% capacity
Calendar life
Most packs last many years if stored cool and partially charged (≈40–60%). High heat and constant 100% charge accelerate aging.
What changes your runtime
- AC vs DC: Inverters waste heat; DC is more efficient.
- Load level: Heavier loads run less efficiently; very tiny loads can be penalized by idle draw.
- Temperature: Cold batteries deliver less energy; hot packs may throttle.
- Device behavior: Motors and compressors surge on startup; heaters draw constant power.
- Background draw: Screens, LEDs, or “always-on” features consume power.
- Age/chemistry: Capacity fades with cycles and calendar time.
FAQ
Can a 500W station run a 500W device?
Yes—if the continuous rating is truly 500W and surge is handled. With a 500Wh battery, expect roughly 0h 51m of runtime on AC (about 51 minutes) under ideal conditions.
What battery size should I look for?
Match Wh to your needs: for light loads (phones, routers, lights), ~300–500Wh is fine. For overnight CPAP, mini-fridge, or TV, 500–700Wh is more comfortable. Multiply your device watts by the hours you want, then divide by 0.85 (AC) or 0.95 (DC) to size the battery.
Does using two devices at once change the math?
Add the watts together. For example, a 100W TV + 120W console ≈ 220W. A 500Wh pack on AC gives about 1.93 h (≈1h 56m).
