The iPhone 11 Pro Max launched in 2019 with a 3,969 mAh battery that was among the longest-lasting of its time, and a phone that now needs charging by midday has a battery with at most a few years of full capacity left. Apple's Battery Health screen, Settings, Battery, Battery Health and Charging, shows maximum capacity as a percentage of new and the Peak Performance Capability message; for a phone of this age a figure of 80 percent or lower means a service replacement is due, and the phone may slow itself if it cannot supply peak power.
The checks in more detail
The 11 Pro Max has an OLED screen, so dark mode and lower brightness help, and the iPhone 11 Pro Max runs iOS 26, so it spends time on background tasks after updates. Background App Refresh and Location Services set to Always are silent drains, and 5G is not a factor since the 11 series has LTE only, so weak LTE signal is the radio cost. Apple's page on a battery that drains too quickly lists the order of checks. iOS 26's Optimized Battery Charging learns your routine; keep it on. A battery that falls suddenly from thirty percent has worn out.
Because the 11 Pro Max is a few years old, check also the camera and Bluetooth accessories you keep connected, since an Apple Watch or earbuds that stay connected all day add a small draw, and a phone that sits in a car holder with the screen on navigation uses far more power than one in a pocket. Reducing these habits, along with a battery replacement, gives the most noticeable gain. If your phone has had its battery replaced by a third party, check Battery Health for a message about an unknown part, which may limit features and give inaccurate readings.
A genuine Apple battery shows full information; a non-genuine one often drains quickly or fails early, so consider an Apple service if the replacement is poor. An older iPhone can also be slowed by iOS 26 compared with its first year, and a lighter set of widgets and background features reduces both heat and drain. Review Settings, Notifications for apps that send many alerts, since each alert wakes the display and radio, and use scheduled summaries for non-urgent apps. This quiet clean-up is free and often adds an hour to the day.
Differential
Likely causes of “Apple iPhone 11 Pro Max battery drains too quickly”, and how to tell them apart
- 1
A battery near the end of its life
What separates it Battery Health shows about eighty percent or less
How to confirm Ask Apple for a battery replacement
- 2
The OLED panel at high brightness
What separates it The display tops the usage list
How to confirm Use dark mode and Auto-Brightness
- 3
Apps refreshing and tracking in the background
What separates it Several apps show long background time
How to confirm Limit Background App Refresh and set location to While Using
- 4
A weak LTE signal on a phone with no 5G
What separates it The radio runs hot in poor coverage
How to confirm Use Wi-Fi at home and Airplane Mode in dead spots
- 5
An iOS 26 re-index after an update
What separates it Heavy drain for a few days
How to confirm Plug it in overnight and judge after a week
Before you touch a setting
Record this first — changing settings destroys the evidence
- Maximum capacity and whether performance management is applied
- Which apps lead the Battery list over ten days
- The signal strength in your usual spots
- The date of the last iOS update
Try in this order
0 of 6 completedRead Battery Health
ReversibleSettings, Battery, Battery Health and Charging.
Turn on dark mode
ReversibleSettings, Display and Brightness.
Limit background refresh
ReversibleSettings, General, Background App Refresh.
Review location access
ReversibleSettings, Privacy and Security, Location Services.
Use Low Power Mode on long days
ReversibleSettings, Battery.
Plan a battery service
ReversibleIf capacity is low.
Model-specific
What is true of this model and not of its siblings
- 2019 battery
- It has several years of wear.
- LTE only
- No 5G drain on this model.
- A record helps
- Dates and versions speed up support.
Stop boundary
When this stops being a self-service repair
- !Capacity near eighty percent means ask Apple about a replacement
- !Shutdowns with charge left need a battery service
- !A swollen battery means stop using the phone
Evidence ledger
Sources behind this answer
Exact questions
Common questions
How long should an 11 Pro Max battery last?+
About a day when healthy.
Does it have 5G?+
No.
Is a replacement worth it?+
Often.
What is performance management?+
The phone limiting itself to avoid shutdowns.