How long does the 20000mAh battery last on one charge?

Runtime depends on the speed you set. Expect many hours at low airflow and far fewer at full blast. The listing gives no exact hour figures, so treat high-speed use as the biggest drain.

It charges over USB, so a phone charger, laptop port or power bank works. A battery this size takes a while to fill from a small adapter; a higher-output USB charger is faster.

Does the remote need batteries?

The remote is included, but the listing does not say what powers it or whether batteries come in the box. Check the remote's battery type before a trip.

Can I use it while it charges?

The listing does not state pass-through charging. If you need all-day airflow, charge it fully beforehand rather than counting on running it plugged in.

Is it good for a tent or a small room?

Yes for personal cooling: the high-velocity airflow and stepless dial let you aim a strong breeze at a bunk or work area. It is a personal fan, not a room cooler, so it will not lower the temperature of a large space.

How does it compare with smaller camping fans?

Smaller fans are lighter and cheaper to carry but run for a few hours per charge and offer only preset speeds. This one trades portability for a much larger battery and finer airflow control.