20,000 mAh to watt-hours
74.0 Wh
20,000 mAh at 3.7 V (lithium-ion cell voltage) · allowed in carry-on (under 100 Wh)
20,000 mAh by voltage
| Nominal voltage | Energy |
|---|---|
| 1.2 V | 24.0 Wh |
| 3.2 V | 64.0 Wh |
| 3.7 V | 74.0 Wh |
| 3.85 V | 77.0 Wh |
| 5 V | 100.0 Wh |
| 7.4 V | 148.0 Wh |
| 12 V | 240.0 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: ~3.2 charges of a 15 Wh phone, ~0.8 of a 60 Wh laptop.
FAQ
How many Wh is 20,000 mAh?
74.0 Wh at 3.7 V.
Can I fly with a 20,000 mAh power bank?
At 74 Wh, yes, under the 100 Wh limit; keep it in carry-on, not checked bags.