The math of an outage
A modern smartphone holds roughly 12–20Wh of energy. A full charge from empty takes about that much, plus ~20% lost as heat. So a three-day outage where you charge two phones once a day needs roughly 100–150Wh of stored power — before you run a single light. Here's how the options stack up, from smallest to largest.
Level 1: A solar power bank (20,000mAh / ~74Wh)
A 20,000mAh solar power bank ($29.99) holds about 74Wh and can recharge most phones multiple times. The built-in solar panel trickle-charges it during the day, stretching that further. It also has an LED flashlight and, on this model, a compass. This is the minimum I'd recommend for any household: cheap, pocket-sized, and it lives in a drawer until you need it.
Best for: keeping phones alive through 1–3 day outages.
Level 2: Add solar lighting
Phone power is only half the problem — you also need light without burning candles. A rechargeable solar lantern ($26.99) charges itself in daylight and runs for hours at night across three brightness modes. Pair it with the power bank and you've covered the two things that make a blackout miserable, for under $60. Both are included in our Tropical Storm Outage Kit.
Best for: comfortable 2–4 day outages without touching a fuel-powered generator.
Level 3: A portable power station (155Wh)
When outages stretch toward a week — or you need to run more than phones — step up to a portable power station ($144.99). At 155Wh with a 150W AC outlet plus USB ports, it can top up phones, tablets, and small electronics during an outage. It recharges from a wall outlet, car charger, or solar panel.
Unlike gas generators, it's silent, safe indoors (no carbon monoxide), and needs no fuel storage. It's the centerpiece of our Category 4–5 Hurricane Kit.
Best for: week-long outages and working from home through a blackout.
What about a gas generator?
For whole-house backup through a multi-week outage, a gas or dual-fuel generator (2,000W+) is still king — but it comes with real tradeoffs: $500+, loud, must run outdoors away from windows (carbon monoxide kills every hurricane season), and needs stabilized fuel storage. For most households preparing for typical storm outages, the battery options above cover the realistic scenarios at a fraction of the cost and hassle.
The 10-minute prep routine
- Charge the power bank and power station to 100%.
- Put the lantern somewhere you'll find it in the dark.
- Download offline maps and save emergency numbers.
- Turn on battery-saver mode and lower screen brightness when the outage starts — it can double your phone's runtime.