If a Pixel 9 Pro loses charge overnight, there is a documented Android 16 bug to check first. Since the March 2026 system update, a confirmed fault has hit Pixel owners in which the GNSS module, the chip that handles GPS and other satellite positioning, refuses to enter its sleep state, which stops the main processor entering Doze and burns battery with the screen off. One Pixel 9 Pro owner lost almost 10 percent overnight at idle.
Google merged a fix in the July update for the Pixel 9, 9 Pro, 9 Pro XL, 10, 10 Pro, 10 Pro XL and 10a, but more than fifty comments under the closure say their phones still drain. A workaround that guides give is to turn off Auto-switch to mobile network under Adaptive Connectivity to stop unexpected radio handoffs. Past that, the usual Pixel order applies: look at Battery usage, update, and check battery health.
Differential
Likely causes of “Google Pixel 9 Pro battery drains too quickly”, and how to tell them apart
- 1
The Android 16 GNSS module bug
What separates it About 10 percent lost overnight at idle since the March 2026 update
How to confirm Install the July update or later; if drain remains, report it under the Google issue tracker thread
- 2
Adaptive Connectivity switching radios
What separates it Drain with the phone idle and signal changing
How to confirm Settings, Network and internet, Adaptive Connectivity: turn off Auto-switch to mobile network
- 3
An app using the most in the background
What separates it One app tops Battery usage
How to confirm Settings, Battery, Battery usage: restrict it
- 4
A worn cell
What separates it Percent falls in steps
How to confirm Settings, Battery, Battery health, or the Pixel diagnostics app
- 5
Weak signal
What separates it Drain is worst where signal is poor
How to confirm Use Wi-Fi or Airplane mode where there is no signal
Before you touch a setting
Record this first — changing settings destroys the evidence
- Overnight loss with Wi-Fi on and nothing running
- The Android version and security patch date
- The top apps under Battery usage
- Whether Adaptive Connectivity's auto-switch is on
Try in this order
0 of 6 completedInstall the newest update
ReversibleSettings, System, System update; Google's fix was in the July release.
Turn off auto-switch
ReversibleSettings, Network and internet, Adaptive Connectivity.
Read Battery usage
ReversibleSettings, Battery, Battery usage.
Restrict the heavy app
ReversibleApp battery usage, Restricted.
Force restart
ReversibleHold the power button about thirty seconds.
Check battery health
ReversiblePixel diagnostics or Settings, Battery.
Model-specific
What is true of this model and not of its siblings
- The GNSS clue
- A satellite positioning chip that will not sleep keeps the processor from Doze, which looks like a software drain with the screen off.
- Where the fix stands
- Google closed the issue with the July update, though more than fifty comments say it persists.
Stop boundary
When this stops being a self-service repair
- !If drain persists on the July update or later, add your device and build to the Google tracker and the Pixel community
- !If the battery is worn, ask Google or a repair partner about replacement
- !A hot or swollen phone must go to service
Evidence ledger
Sources behind this answer
Google's charging and battery guidance.
The GNSS sleep bug and the July fix.
What the July update fixed and what remains.
Causes and settings to change.
Pixel 9 Pro battery, wired and wireless charging, display and modem.
Exact questions
Common questions
Why does my Pixel 9 Pro drain overnight?+
A confirmed Android 16 bug kept the GNSS chip awake from March 2026; Google's fix arrived in the July update, though some owners still report drain.
What does Adaptive Connectivity do?+
It switches between Wi-Fi and mobile data automatically; turning off Auto-switch to mobile network stops radio handoffs.
Which Pixels were fixed in July?+
The Pixel 9 line, the Pixel 10 line and the 10a.
Is a 10 percent overnight loss normal?+
No; a few percent is.