Power & batteries
Convert mAh to Wh, estimate phone charges from a power bank, size portable solar and keep batteries working in the cold, with airline limits.
Battery labels mix units, and solar panel ratings describe laboratory sunlight. These guides convert everything to watt-hours, state the efficiency assumptions openly and show where cold and cloud change the budget.
- 016 min read
Converting mAh to watt-hours, and why Wh is the figure to compare
Convert mAh to watt-hours with Wh = mAh ÷ 1,000 × volts, and see where 10,000 to 30,000 mAh banks sit against the 100 Wh and 160 Wh airline limits.
- 026 min read
How many phone charges a power bank gives, and how to estimate it
Estimate phone charges from a power bank by dividing usable watt-hours by the phone battery energy, with 60% and 80% scenarios for a 10,000 mAh bank.
- 037 min read
How much power a portable solar panel makes on a trip
Estimate daily solar charge from panel watts, equivalent sun hours and charging losses, with angle and cloud scenarios for a 10 W backpacking panel.
- 046 min read
Why batteries deliver less energy in the cold, and how to plan for it
Why a phone or power bank delivers less energy in cold weather, how to model the loss as a lower efficiency scenario, and what to do on the trip.