Watt-hours decide your rig. The airline decides your watt-hours.
A battery rated 26,800 mAh sounds enormous. Whether you can board with it depends on a number the label may not print.
Two batteries both say 20,000 mAh. One runs your rig twice as long as the other.
The rating is incomplete. Milliamp-hours describe charge, and charge only becomes energy once you know the voltage.
The conversion
Watt-hours = milliamp-hours times volts, divided by 1000.
A 20,000 mAh cell at 3.7 V is 74 Wh. The same figure at 14.8 V is 296 Wh. Same headline number, four times the energy. Compare watt-hours or compare nothing.
Spare lithium batteries up to 100 Wh travel in carry-on with no approval. From 100 to 160 Wh you need airline approval and you are limited to two. Above 160 Wh they do not fly on passenger aircraft.
Why this shapes a mobile rig
The 100 Wh line is the one to build to. Anything under it crosses borders without a conversation. Cross it and every trip becomes a negotiation with a desk agent who has seen a lot of confident people.
Spares go in the cabin. Not in checked baggage. Terminals need covering or the battery needs to be in its own bag.
Sizing it against your draw
| Load | Rough draw | Hours from 99 Wh |
|---|---|---|
| Phone streaming, screen on | 5 to 8 W | 12 to 19 |
| Phone plus two modems | 12 to 18 W | 5 to 8 |
| Encoder box plus modems plus camera | 25 to 40 W | 2.5 to 4 |
Take 15% off for conversion losses. A battery pack does not deliver its rating through a DC converter.
Two things people learn late
- Cold cuts capacity. A pack rated at room temperature delivers less on a winter shoot.
- Charging and discharging at once is slower than either. Passing power through a pack while it runs your rig wastes energy as heat, and the pack gets warm enough to throttle.
Build to 99 Wh per pack and carry two. That clears the gate and covers a long day.
Sources
The Rig Wire reports on streaming technology from public documentation, source repositories and vendor releases. We did not bench-test what is described here. When we have tested something, we say so.