Apple

iPhone 15 Pro

The source for iPhone 15 Pro gives 12.7 Wh and 3,274 mAh.

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Check before use

Battery size does not determine charging speed. Check the charging protocol too.

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The short answer

The iPhone 15 Pro battery stores 12.7 watt-hours.

The calculations below use the model-specific figure of 3,274 mAh. This is not a generic assumption for every smartphone.

Stated energy: 12.7 Wh
Stated capacity: 3,274 mAh
Nominal voltage: 3.87 V

Power-bank calculation

How many full charges?

We take 75% of the power bank's stated Wh and divide by this phone's 12.7 Wh. This remains a planning estimate.

5,000mAh class≈ 1.1×

18.5 Wh rated → 13.9 Wh planned delivery

10,000mAh class≈ 2.2×

37 Wh rated → 27.8 Wh planned delivery

20,000mAh class≈ 4.4×

74 Wh rated → 55.5 Wh planned delivery

(Power-bank Wh × 0.75) ÷ 12.7 Wh

A cold or older battery can supply less energy.

Cold and battery ageing

The estimate uses the battery data and calculation assumptions shown with this result. That is not a measurement of the battery’s current condition. Cold and battery ageing are not calculated separately.

Cold is not the same as wear. Cold can temporarily limit the available energy and the power that can be delivered. Ageing can permanently reduce the storage capacity, even when the screen shows ‘100% charged’.

Follow the temperature limits for charging and using from the manual of your model. Check important applications with your own setup.

More about our battery assumptions

Charging speed and sourcesWhat the phone, charger and cable must support.ViewClose

Capacity is not speed

12.7 Wh tells you how much energy.
Charging power tells you how fast.

Wired chargingFast-charge capable with a 20W or higher USB-C adapter

The phone, adapter and cable must support the required charging profile.

Wireless chargingUp to 15W with MagSafe or Qi2; up to 7.5W with Qi

Alignment, heat and certification affect actual power.

Sources

Two sources with different roles.

The manufacturer supports the phone and charging claims. The model-specific battery source supplies the battery figures used in our calculation.

Manufacturer specificationApple specifications ↗Model-specific battery sourceBattery data via iFixit ↗Source record checked on 2026-08-21. We have not physically tested this phone.

Questions and comparisonsMore explanation and other phones.ViewClose

Frequently asked questions

Keep energy and charging power separate.

How many Wh does the iPhone 15 Pro battery store?

The model-specific source gives 12.7 Wh and 3,274 mAh. Watt-hours are the useful basis for comparison with a power bank.

How often can a 10,000mAh power bank charge the iPhone 15 Pro?

A power bank rated around 37 Wh provides about 2.2 full charges in this estimate. We assume 75% of its rated energy reaches the phone battery.

Does 12.7 Wh mean the phone charges at 12.7 W?

No. Wh is stored energy; W is charging power at a particular moment.