Best power banks to keep phones charged in an outage (2026)
Ready.gov's basic kit includes a cell phone with chargers and a backup battery. A charged power bank keeps your phone, and your alerts and calls, going through an outage. Here they are compared on capacity, output and the extras that matter.
By PreparedStates editors · Updated October 22, 2026 · 4 products, 1 of 4 price-tracked
Our picks
Anker 20,000mAh (built-in cable)
The one to keep in the kitchen drawer
Anker 737
Laptop-grade power bank
INIU 20,000mAh 45W
Budget 20,000 mAh
All 4 compared
| Power bank | Capacity | Max output | Extras | Price |
|---|---|---|---|---|
20,000 mAh · 87 W · Built-in USB-C cable The one to keep in the kitchen drawer | 20,000 mAh | 87 W | Built-in USB-C cable | |
Our verdictOur verdictResearched 20,000 mAh (several phone charges) with a built-in cable, so the cable can't go missing when you need it. Enough output for a laptop. Best for The one to keep in the kitchen drawer Good
Worth knowing
Who shouldn't buy it: Don't buy it if you only need a pocket-sized top-up. | ||||
24,000 mAh · 140 W · Digital display Laptop-grade power bank | 24,000 mAh | 140 W | Digital display | |
Our verdictOur verdictResearched 24,000 mAh and 140 W: charges a laptop at full speed and shows exactly how much is left. Overkill for phones only. Best for Laptop-grade power bank Good
Worth knowing
Who shouldn't buy it: Don't buy it if you only charge phones. | ||||
4.0 | 20,000 mAh | 45 W | Digital display | |
Our verdictOur verdictResearched A cheaper 20,000 mAh bank with a display and 45 W output: plenty for phones and tablets. Best for Budget 20,000 mAh Good
Worth knowing
Who shouldn't buy it: Don't buy it if you need to charge a laptop quickly. | ||||
8,000 mAh · Works down to -40°F For winter storms and cold cars | 8,000 mAh | — | Works down to -40°F | $84.95 at Nitecore Store Checked Oct 22In stockCheck price → |
Our verdictOur verdictResearched Ordinary power banks lose charge and refuse to work in deep cold; Nitecore says this one keeps going down to -40°F. Small capacity. Best for For winter storms and cold cars Good
Worth knowing
Who shouldn't buy it: Don't buy it if you live somewhere mild. | ||||
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Before you buy
20,000 mAh gives several phone charges; that's the sweet spot for an emergency bank.
Output (watts) decides what it can charge: 20-30 W is fine for phones, 65 W-plus charges laptops.
A built-in cable or display is worth having: one less thing to lose, and you can see what's left.
Deep cold drains ordinary batteries.
For winter storms, keep the bank inside your coat or choose a cold-rated model.
We verify every product's specifications against at least two independent sources, re-check its US price and stock on a schedule where we can track it automatically, and cross-check safety-relevant claims against official guidance. Every review is labelled Researched or Used and reviewed by us: where we've bought a product, or been sent it free, and used it ourselves, its review says which; where we haven't, our verdict is a considered spec-and-evidence comparison, not a hands-on test — and commissions never change a ranking either way. Read our full methodology →
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Common questions
What size power bank do I need for an emergency?
About 20,000 mAh for one or two people: several full phone charges. Pair it with a power station or solar for longer outages.
How long does a power bank hold its charge?
Months, but it slowly loses charge. Top it up every couple of months and before storms.
Can a power bank charge a laptop?
If it has enough output: around 65 W or more for most laptops, like the Anker models here.
Are power banks allowed on planes?
Usually in carry-on only, and within airline capacity limits. INIU says its 20,000 mAh model is TSA-compliant.