How to choose a power bank

Start with capacity

A power bank's capacity is how much energy it stores, and the honest unit is watt-hours (Wh). You'll also see mAh on packaging — a bigger number that looks impressive but only means something alongside a voltage. Watt-hours let you compare banks fairly.

As a rough guide, a modern phone battery holds somewhere around 15–20Wh. So a 50Wh power bank is good for roughly two to three full phone charges, and a larger bank scales from there. Think in "how many top-ups do I need between mains power," not in raw numbers.

Then output

Capacity is how much it holds; output is how fast it gives it back, measured in watts. A bank with plenty of capacity but low output will charge a phone slowly and may not charge a laptop at all. If you want to top up a laptop on the move, check the bank's output wattage covers it — the same rule as any charger.

Higher output also matters if you're charging more than one device at once, since that power is shared.

Size and weight are the trade-off

More capacity means more cells, which means more weight and bulk. The right size depends entirely on the trip:

• A day out, or a commute: a small, light bank for one emergency top-up is genuinely nicer to carry than a heavy one you resent.
• A weekend away or a long-haul flight: more capacity earns its weight.
• Off-grid for days: you're into larger banks or a portable power station.

There's no single "best" size — only the best size for how you travel.

Features worth having

Pass-through charging (using the bank while it charges) is handy on a busy desk. USB-C in and out means one cable does everything. A bank that recharges quickly itself is less likely to be flat when you grab it.

A note on flying

Airlines limit the size of lithium batteries in carry-on and usually ban them from checked bags. Most everyday power banks are well within the limit, but very large ones can be restricted, so check before a flight with a big bank.

Charging the bank itself

One thing people forget to check is how the power bank recharges, because a bank that takes all night to refill is often flat exactly when you need it. Look for USB-C input and a decent input wattage, so the bank tops up quickly between uses rather than trickling. USB-C in and out also means one cable does everything — charging the bank and charging your devices — which is one less thing to carry. Pass-through charging (running a device from the bank while the bank itself charges from the wall) is a genuine convenience on a busy desk, letting the bank sit permanently in the loop. And if you travel, a bank that refills fast is far more useful than a slightly larger one that's always half-empty, because a bank you can top up over a coffee break is always ready to go.

KORD's range

KORD lists capacity in watt-hours and output in watts, so you can match both to your trip rather than guessing from an mAh figure. Not sure which to carry? hello@kord.nz — tell us the trip and we'll suggest a size.