iPhone 11 128GB Battery: Capacity and Health

The iPhone 11 128GB has a nominal battery capacity of 3,110mAh, or 11.91Wh. The 128GB figure describes storage for apps, photos and files; it does not mean this version has a larger battery than the 64GB or 256GB iPhone 11. iFixit’s iPhone 11 teardown documents the battery capacity.

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If you are checking a used phone, distinguish that original specification from its remaining capacity today. A listing that says “3,110mAh” identifies the model’s original battery specification; it does not establish the condition of the battery inside that particular phone.

The 128GB model has the same battery as the others

Apple lists all three storage configurations under the same iPhone 11 specifications, with one set of battery endurance claims. Its technical specifications describe a rechargeable lithium-ion battery but do not publish its mAh rating. The 3,110mAh and 11.91Wh figures come from the battery documented in the teardown, rather than an mAh figure on Apple’s consumer specifications page. Apple’s iPhone 11 specifications, iFixit’s teardown.

These units answer different questions. Gigabytes measure data storage. Milliamp-hours describe electrical charge capacity. Watt-hours describe stored energy. None of them, by itself, tells you how many hours a particular used phone will last between charges.

There is no storage version to warn against on battery-capacity grounds: all three have the same original rating. Choose 128GB because you need that storage space. Moving to 256GB does not buy additional battery capacity, and choosing 64GB does not mean accepting a smaller battery.

These figures apply to the standard iPhone 11. Do not assume that a battery or replacement part advertised for an iPhone 11 Pro or Pro Max is interchangeable simply because its name includes “11.”

What 3,110mAh means for time between charges

Apple rates the iPhone 11 for up to 17 hours of video playback, 10 hours of streamed video, or 65 hours of audio playback. Those are separate manufacturer test scenarios, not a promise of 17 hours spent switching between maps, the camera, games and social apps. Apple’s battery specifications.

Independent measurements provide a useful second reference. Notebookcheck measured 14 hours 26 minutes of Wi-Fi web browsing and 19 hours 7 minutes of H.264 video playback in its 2019 iPhone 11 review. Its maximum-brightness load test lasted 4 hours 27 minutes. That spread demonstrates how strongly the workload affects endurance even with the same battery. Notebookcheck’s measured battery results.

Notebookcheck’s video result exceeding Apple’s claim is not evidence that either figure is wrong: the test procedures differ. Neither figure predicts the runtime of a refurbished handset years later, with different software and an unknown battery history.

For a purchase decision, use these measurements as historical context. The unresolved number is the endurance of the individual phone you will receive. A model specification cannot establish that. If battery life is your main reason for comparing older models, the guide to older iPhones for gaming and battery life addresses that broader choice.

Check remaining capacity before buying a used 128GB phone

On an iPhone 11, open Settings → Battery → Battery Health & Charging and check Maximum Capacity and any service recommendation. Apple documents this menu specifically for iPhone 11 through iPhone 14 models. Apple’s battery health instructions.

Maximum Capacity is different from the charge percentage in the status bar. A phone can finish charging to 100% while its battery health is substantially below 100%: it has filled its currently available capacity.

For illustration, multiplying the original rating by the health percentage gives:

• 90% health: 3,110 × 0.90 = approximately 2,799mAh.
• 85% health: 3,110 × 0.85 = approximately 2,644mAh.
• 80% health: 3,110 × 0.80 = approximately 2,488mAh.

These are arithmetic illustrations, not measured capacities or diagnostic readings. They should not be used to predict an exact number of screen-on hours.

Apple says batteries in iPhone 14 models and earlier are designed to retain 80% of original capacity after 500 complete charge cycles under ideal conditions. That is a design benchmark, not a guarantee that every iPhone 11 reaches the same percentage at the same age. Apple’s battery ageing guidance.

Consider the Apple iPhone 11 128GB Unlocked (Renewed) only if you specifically want this model and can verify the supplied phone’s battery condition. Its drawback is that the original 3,110mAh specification cannot guarantee the remaining capacity of a renewed unit. Ask for the actual handset’s health reading and repair history; a generic model screenshot does not resolve either question.

Also check Settings → General → About → Parts and Service History, when that section is present. Apple warns that battery health information may be inaccurate when the phone cannot verify its battery. An “Unknown” battery message can have several causes, including an unverified replacement or a battery that is not functioning as expected; it does not establish one specific cause by itself. Apple’s explanation of genuine batteries and repair history.

There is one iPhone 11-specific complication worth checking before interpreting an unusual percentage. Apple introduced battery-health reporting recalibration in iOS 14.5 for the iPhone 11 family. If the phone explicitly displays a recalibration message, Apple says the process can take a few weeks during regular charge cycles. Recalibration corrects the estimate; it does not physically restore a worn battery. If the phone recommends service after recalibration, contact Apple Support for service options. Apple’s iPhone 11 recalibration guidance.