The iPhone XS Max has a 3,174 mAh battery, and by now most of them have aged enough that a day of use is a stretch. Apple's Battery Health screen, available on the XS Max since iOS 13.1, shows maximum capacity as a percentage of the battery when new, and a figure well under 80 percent is the point at which Apple regards a battery as consumed.
It also reports Peak Performance Capability, which says whether the battery can still deliver the bursts the phone needs. Before blaming age, check what is using the power: Settings, Battery lists apps by use in the last 24 hours or ten days, and Background App Refresh, Location Services and a bright screen are the usual hidden costs. A poor cellular signal makes the radio work harder, and an iOS 18 update can raise drain for a day or two while the phone re-indexes.
Differential
Likely causes of “Apple iPhone XS Max battery drains too quickly”, and how to tell them apart
- 1
A worn battery
What separates it Battery Health shows low maximum capacity
How to confirm Book an Apple or authorized battery service
- 2
Background activity and location
What separates it The usage list shows apps with high background time
How to confirm Settings, General, Background App Refresh: limit it; Privacy, Location Services: set apps to While Using
- 3
A weak cellular signal
What separates it The phone is warm and drains faster in poor coverage
How to confirm Use Wi-Fi at home or Airplane Mode in poor coverage
- 4
A post-update re-index
What separates it Drain rises for a day or two after an update
How to confirm Leave the phone plugged in overnight and check again after two days
- 5
A bright screen and always-on features
What separates it The screen is the top user in the list
How to confirm Lower brightness, turn on Auto-Brightness and Low Power Mode
Before you touch a setting
Record this first — changing settings destroys the evidence
- The maximum capacity and Peak Performance Capability in Battery Health
- The top apps in the usage list
- Signal strength where you use the phone
- When the drain started
Try in this order
0 of 6 completedRead Battery Health
ReversibleOpen Settings, Battery, Battery Health and note the maximum capacity and the message about peak performance.
Open the usage list
ReversibleSettings, Battery shows each app's use; look for one that is much higher than the rest.
Limit background refresh
ReversibleSettings, General, Background App Refresh: turn it off for apps you do not need updating in the background.
Change location access
ReversibleSettings, Privacy and Security, Location Services: set most apps to While Using the App or Never.
Use Low Power Mode when needed
ReversibleSettings, Battery, Low Power Mode reduces background activity and can add hours on a tired battery.
Consider a battery service
ReversibleIf capacity is low, a replacement is the only change that restores a full day.
Model-specific
What is true of this model and not of its siblings
- Battery Health arrived in iOS 13.1
- The XS Max has the feature, so the percentage you see is Apple's own measure.
- The 80 percent line
- Apple treats a battery under 80 percent of its original capacity as consumed.
- Signal matters
- Poor coverage can double the radio's power use.
Stop boundary
When this stops being a self-service repair
- !If maximum capacity is under about 80 percent, ask Apple or a certified repairer about a battery service
- !If the phone shuts down at 30 to 40 percent, a battery service is needed
- !A swollen battery means stop using it
Evidence ledger
Sources behind this answer
Exact questions
Common questions
How long should an XS Max battery last?+
A new one lasts about a day; an aged one often needs a midday top-up.
What is Peak Performance Capability?+
It says whether the battery can still deliver the power bursts the phone needs.
Is replacing the battery worthwhile?+
Often yes, since it restores a day of life.
Does Low Power Mode help?+
Yes, it reduces background activity.