MacBook Battery Draining Overnight? Here's the Fix

A sleeping MacBook can still perform brief background wakes with the display off. Those wakes, connected devices, or a process preventing sleep can explain an unexpected overnight drop, but the log and usage history should identify the pattern before you change settings. This guide starts with read-only checks, then moves to reversible options.

Quick answer

Open System Settings → Battery → Options and turn off Power Nap, when that option is available, and Wake for network access. Do not force an undocumented Power Nap setting on Apple silicon just because the Intel-only control is absent. Then read the wake log with pmset -g log | grep -e "Wake from" -e "DarkWake" -e "due to" to confirm the wakes stopped. That covers the large majority of cases. If the drain continues, a single process is holding a sleep assertion, and that is the part a watt-based monitor helps you find.

Why your MacBook wakes up while “asleep”

Each DarkWake lasts only seconds, but the CPU, disk, and Wi-Fi radio all draw real power for those seconds. Enough wakes in a row will drain a noticeable chunk of battery by morning. The rate of wakes is what separates a healthy night from a bad one.

The worst offenders are well documented:

Power Nap schedules wakeups for email, iCloud, and Calendar sync. On some Macs the option only appears while on AC power.
Wake for network access lets the Mac be roused for Bonjour, AirPlay, and remote screen sharing.
Bluetooth peripherals, a plugged-in AirPods case, USB hubs, and external drives can each hold a wake assertion or draw power while the lid is closed.
Cloud sync jobs are the biggest real culprit when the toggles are already off. iCloud Photos (photoanalysisd, cloudphoto), iCloud Drive (cloudd, nsurlsessiond), Spotlight reindexing, Docker containers, and cloudflared tunnels all keep the CPU busy for as long as they have work queued.

Find out what kept it awake

Before changing anything, read the logs. macOS records every wake and the reason for it, and the built-in pmset tool exposes that history.

Run this in Terminal to list every wake and its cause over the last sleep cycle:

pmset -g log | grep -e "Wake from" -e "DarkWake" -e "due to"

To see your current sleep settings for both battery and AC, run pmset -g custom. To see what is actively preventing sleep right now, run pmset -g assertions and look for lines marked PreventUserIdleSystemSleep. That line names the process holding the wake.

If you prefer a GUI, open System Settings → Battery → Usage History. It charts battery level over the last 24 hours and the last 10 days, and you can usually spot the overnight cliff at a glance. Activity Monitor's Energy tab adds two columns worth turning on from the View menu: Preventing Sleep and Idle Wake Ups. Sort by either to find the process that is misbehaving.

Turn off the settings that cause overnight drain

Most overnight drain cases stop here. These toggles all live under one screen.

Open System Settings → Battery → Options and set:

Power Nap: off. Stops the scheduled email, iCloud, and Calendar wakes. This toggle is available on supported Intel Macs. If the option is absent, leave it alone.
Wake for network access: off. Stops the Mac from being roused for Bonjour and remote access.

Keep the Terminal checks in this guide read-only. Broad sudo pmset -a commands change battery and adapter behavior together, can disable services you rely on, and are difficult to reverse without recording the previous values. Use the documented Battery options first.

Then unpair anything that can wake the machine. A Bluetooth mouse or keyboard nudging the Mac awake, an AirPods case left plugged in, or a USB hub with always-on power can each be the culprit. Open System Settings → Bluetooth and disconnect what you do not need overnight. Physically unplugging hubs and external drives before closing the lid is the surest fix for peripheral draw.

Hunt down the runaway process

When the toggles above are off and the battery still drops, the cause is usually a single process holding a sleep assertion while it churns through work. iCloud Photos reprocessing a large library, iCloud Drive uploading a big folder, Spotlight reindexing after an update, Docker running a container, or a launchd agent like cloudflared that never sleeps.

Activity Monitor can point you at these, but its Energy Impact score is a unitless number and its Preventing Sleep column does not tell you how much power each process actually costs. A watt-based monitor makes the runaway obvious: the process pulling four watts at 3 a.m. while everything else sits near zero is the one to stop.

That is where MacBookBatteryMonitor fits: it shows live per-app power draw in watts so you can see the offender directly, surfaces the hidden launchd agents and sync daemons that Activity Monitor buries, and stops the process in one click instead of a kill command. It diagnoses the process the System Settings toggles cannot reach. For the broader picture of which apps pull the most power, see our guide on MacBook battery usage by app.

When to just shut down instead

For a single worknight, sleep is fine once the drainers above are off. The math changes for longer idle periods.

Sleep still burns a small amount of power for every DarkWake, even a healthy one. Across 12 or more hours of idle time, those small wakes add up to more than a full shutdown would. If you are leaving the Mac unused over a weekend or a trip, shut it down instead.

One Apple silicon note: there is no separate SMC-reset procedure for M-series Macs. If sleep behavior still seems broken, shut down normally, leave the Mac off briefly, restart it, and retest before escalating to Apple Diagnostics or support.

FAQ

How much battery drain overnight is normal?

Apple does not publish a universal overnight-loss threshold. Sleep drain varies with model, battery health, connected devices, network settings, and background work. Establish your own baseline over several nights, then investigate a repeatable increase with Battery usage history and the read-only `pmset` logs.

Does closing the lid put the MacBook to sleep?

It normally puts a MacBook to sleep, but macOS may perform brief background wakes depending on the model, settings, connected devices, and scheduled work. Closing the lid is not the same as shutting down.

What is DarkWake on a Mac?

DarkWake is a macOS wake event in which the display can remain off while the system performs background work. The wake reason in the power-management log is more useful than assuming one particular service caused it.

Will turning off Power Nap stop iCloud sync?

It stops the scheduled background wakes Power Nap performs for email, iCloud, and Calendar while the Mac is asleep. iCloud still syncs normally while you are using the machine. You give up middle-of-the-night background sync, not the sync itself.

Should I shut down my MacBook every night?

Usually not. Sleep is designed for normal day-to-day use. Shutting down is reasonable for a long period when you will not use the Mac, or as a troubleshooting comparison when sleep drain is unusually high.