KWhCalc

2,500 mAh to watt-hours

9.2 Wh

2,500 mAh at 3.7 V (lithium-ion cell voltage) · allowed in carry-on (under 100 Wh)

2,500 mAh by voltage

Nominal voltageEnergy
1.2 V3.0 Wh
3.2 V8.0 Wh
3.7 V9.2 Wh
3.85 V9.6 Wh
5 V12.5 Wh
7.4 V18.5 Wh
12 V30.0 Wh

Wh = mAh × V ÷ 1000. Power banks rate mAh at the 3.6-3.7 V cell voltage, not 5 V USB output.

What it can charge

With about 65% real-world efficiency to the device: ~0.4 charges of a 15 Wh phone, ~0.1 of a 60 Wh laptop.

FAQ

How many Wh is 2,500 mAh?

9.2 Wh at 3.7 V.

Can I fly with a 2,500 mAh power bank?

At 9 Wh, yes, under the 100 Wh limit; keep it in carry-on, not checked bags.