Most people don’t buy the wrong power station because they choose the wrong brand. They buy the wrong size.
This guide walks you through practical sizing for a 72-hour outage—no spreadsheets, no hype.
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Understand Capacity (Wh) in Plain English
Portable power stations are rated in watt-hours (Wh).
That number tells you how much energy is stored.
Think of it as a fuel tank:
- Bigger Wh = longer runtime
- Outputs and efficiency still matter
Step 1: List What You Actually Need to Power
Most blackout setups fall into these categories:
- Phone charging
- Internet router + modem
- Laptop
- LED lighting
- Fan or medical monitoring (general, non-clinical)
If it doesn’t keep you informed, working, or comfortable, it’s optional.
Step 2: Estimate Daily Energy Use (Conservative)
Typical ranges:
- Phone: 10–15Wh per charge
- Router + modem: 60–100Wh/day
- Laptop: 50–100Wh/day
- LED lighting: 20–40Wh/day
- Small fan: 100–200Wh/day
A modest setup often lands around 250–350Wh per day.
Step 3: Multiply for 72 Hours
- 250Wh/day × 3 days = 750Wh
- Add buffer for inverter losses and inefficiency
That’s why many people are underpowered with small units.
Recommended Sizes by Scenario
Minimal Connectivity (≈300Wh)
- Phones
- Router (limited hours)
- Emergency lighting
Balanced Home Use (≈500Wh)
- Phones
- Router + modem
- Laptop
- Lighting
Comfort + Redundancy (≈1000Wh)
- Everything above
- Fans
- Longer runtimes
- Better solar recovery
Common Sizing Mistakes
- Assuming solar panels recharge quickly
- Forgetting AC inverter losses
- Buying “just enough” with no buffer
If you’re between sizes, go up one level.
FAQ
Can solar panels reduce the size I need?
Yes, but only with sustained sunlight.
Is bigger always better?
Only if you’ll use it. Balance portability and runtime.
Can I pair a power bank with a station?
Yes. It’s a smart redundancy setup.
Bottom Line
For a real 72-hour outage:
- 300Wh = survival
- 500Wh = functionality
- 1000Wh = comfort and margin
Related:
- What You Can (and Can’t) Run on a Portable Power Station During a Blackout
- What Size Portable Power Station Do You Need for a 72-Hour Outage?
- Solar Power Bank vs Portable Power Station: What Actually Works in a 72-Hour Outage?
- Best Solar Power Banks for Power Outages (2025 Buyer’s Guide)
- Hiluckey 27,000mAh Solar Charger Review (2025 Update)