BOOX Note Air 4 C · Troubleshooting

The BOOX Note Air 4 C battery drains fast

The Note Air 4 C loses charge quickly even when idle. On an Android e-ink tablet this is almost always background apps, sync, or Wi-Fi left on.

Software: BOOX firmware
Difficulty: Easy
Time: 25 minutes
Last tested: August 2026
Last updated: August 2026

Symptoms

The battery drops 10 percent or more overnight with nothing running.
A full charge lasts a day or two instead of a week.
The device feels warm when it has been sitting idle.
Battery life fell after installing several apps.

Before you start

The Note Air 4 C has a bigger battery than a small reader but also a bigger screen and colour layer; expect several days of mixed use, not weeks.
Note which apps you have installed and signed into — each is a potential drain.
None of these steps remove your books or notebooks.

Which fix do you need?

What does the drain look like?

It has been heavy since I set the device up Restrict background apps and turn Wi-Fi off between syncs
It got worse after I installed several apps One app is likely holding it awake — find it
The device is warm when idle A stuck app or process — restart and check
It drains even in airplane mode Check the optimisation and auto-sync settings

Most common cause

On an Android e-reader the causes, in order, are: reading, store and note apps left running in the background and syncing; Wi-Fi left on so those apps keep checking in; and a specific misbehaving app holding the device awake. BOOX's own power settings control most of this.

Fixes

Fix 1 Restrict background apps and manage Wi-Fi

Reading, store and note apps sync in the background by default, and Wi-Fi left on lets them do it constantly. Restricting them and turning Wi-Fi off between syncs is most of the fix.

Open Settings, then "Power", and set apps you use only occasionally to "optimised" or "restricted".
Keep one or two apps you use constantly exempt so they resume instantly.
Turn Wi-Fi off from the control centre when you are just reading or writing; turn it on to sync, then off again. Or use airplane mode.
In each reading app's own settings, turn off "sync on open" or set the sync interval to manual. Let BOOX Notes sync on a schedule rather than constantly.

Fix 2 Find an app that is holding the device awake

One app with a bug can keep the processor from sleeping, which shows as steady drain and a warm device even with the screen off.

Open Settings, then Battery, and look at the per-app battery usage since the last full charge. An app near the top you have barely opened is the suspect.
Restrict or force-stop that app. If the drain stops over the next day, it was the cause.
Restart the device to clear any process already stuck awake.
If you cannot tell which app, use safe mode for a day. If standby is good in safe mode, a third-party app is the cause; add them back one at a time.

Fix 3 Check optimisation and auto-sync settings

If the device drains even with the radios off, an app is doing local work, or the system's own sync accounts are busy.

Open Settings, then "Accounts", and turn off auto-sync for any account you do not need syncing continuously.
In BOOX's app-optimisation panel, make sure no reading or note app is set to keep running or to disable Android's power management for it.
Let the device sit plugged in and idle for an hour to finish any pending indexing, then unplug and check standby again.
As a last resort, export notebooks as PDF, back up sideloaded books, and do a factory reset, then add apps back carefully.

Undo / recovery

Restricting apps and turning off sync are safe and reversible. A factory reset erases the device's internal storage but not a microSD card or cloud-synced content. Export notebooks first, and only reset if targeted fixes fail.

Start by turning Wi-Fi off between syncs and restricting background apps — that alone brings most units back to several days of standby. If it is still bad, the battery-usage list will point to the one app holding the device awake.