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Why does my MacBook battery drain while sleeping?

Paste pmset -g log and see how much charge your MacBook lost per hour asleep and which dark wakes took the time. Nothing leaves your browser.

By , who makes Keep Mac Awake. . Markdown

Short answer: A sleeping MacBook still uses some battery. With the default hibernatemode 3, a portable Mac "will power memory during sleep" (man pmset), and it wakes for a few seconds now and then with the display off, a dark wake, for Power Nap, for maintenance macOS booked and for network or device events. pmset -g log prints the charge on every sleep and wake line, so the tool above measures how many points your MacBook lost per hour asleep and which kinds of wake took the time awake. If the MacBook should keep working with the lid closed instead of sleeping, the first choice is Keep Mac Awake: it keeps the Mac awake for a session you start, on battery only down to a floor you pick.

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How do I check how much battery my Mac loses while sleeping?

Run this in Terminal after a sleep on battery, such as a night with the lid closed, and paste what it prints into the tool:

pmset -g log | grep -E "Entering Sleep|Wake from"

pmset -g log "displays a history of sleeps, wakes, and other power management events" (man pmset); it only reads, so it needs no sudo. Each sleep and wake line ends with the power source and the charge, which Apple's pmset source prints after the message:

2026-10-29 19:02:36 +0100 Sleep     Entering Sleep state due to 'Clamshell Sleep':TCPKeepAlive=active Using Batt (Charge:71%) 21 secs
2026-10-29 21:02:03 +0100 Wake      Wake from Deep Idle [CDNVA] : due to smc.sysState.Wake(0x70070000) lid SMC.OutboxNotEmpty RTP.multi-touch/HID Activity Using BATT (Charge:70%)

The tool cuts the log into stretches of sleep on battery. A stretch starts when the Mac goes to sleep on battery and runs through the dark wakes that follow, until a full wake (the lid, the keyboard, the trackpad), power connected, a restart or the end of the paste. For each one it shows the charge at both ends, the points lost, the points per hour, the dark wakes and how long they kept the Mac awake.

How accurate is the battery drain number?

As accurate as the log: pmset prints the charge in whole percent, so a stretch of an hour that lost 1 point could have lost a little less or a little more. The reading also moves unevenly. In one real log behind this tool, the charge read 20% when the Mac went to sleep, 17% an hour later and still 17% three hours after that. Read the rate over long stretches, a whole night if you can. The tool gives no rate for a stretch shorter than an hour, and its "8 hours of sleep" figure is a straight line through your own numbers, not a promise.

Why does a MacBook lose battery while it sleeps?

For two kinds of reasons: what sleep itself keeps powered, and the moments the Mac wakes.

  • Memory stays powered. With hibernatemode 3, the default on portables, the Mac keeps a copy of memory on disk "and will power memory during sleep" (man pmset).
  • Dark wakes. A dark wake runs the CPU, disk and network for a few seconds with the display off, then the Mac sleeps again. In the log it is a DarkWake line; which kind it was is the part after the slash.
  • Standby. Standby hibernates a Mac "after it has slept for a specified time period. This saves power while asleep" (man pmset). A wake from Standby in the log shows it happened.

The kinds of dark wake the tool counts:

In the logWhat woke the MacA setting that affects it
rtc/SleepServicePower Nap. "When your Mac goes to sleep, Power Nap activates periodically to update information" (Apple Support)Enable Power Nap
rtc/MaintenanceUpkeep macOS booked from the real-time clock, such as a network lease renewal; Apple's PowerManagement source counts it as a Power Nap wake tooApple does not tie it to a setting
Codes with no wake type, such as wifibt ... ARPT/A hardware driver claimed the wake and macOS logged no type. Apple does not document these driver namesApple's guide to unexpected wakes points to Wake for network access
NetworkA wake for the networkWake for network access

To see the reason for every single wake, with who booked it, paste the same log into Why did my Mac wake up?.

What does TCPKeepAlive=active mean in pmset -g log?

It is the state of macOS's TCP keep-alive mechanism while the Mac sleeps, written on each sleep line by Apple's PowerManagement source: active, inactive, disabled (turned off with pmset tcpkeepalive 0) or unsupported. sudo pmset -a tcpkeepalive 0 turns it off, and Apple's pmset then warns that this "will result in some critical features" not working properly, and names Find My Mac. Apple does not say how much battery it uses, so the tool does not put a number on it. Codes such as E_TKO_TCP_DATA in a wake line are driver names Apple does not document either.

How can I make my MacBook lose less battery while it sleeps?

First decide whether it should sleep at all. If you close the lid so a download, a backup or a coding agent keeps going, a sleeping Mac stops that work however little battery it uses. For that, the first choice is Keep Mac Awake (keepmacawake.com): keepmacawake start --hours 8 keeps a MacBook with Apple silicon and macOS 26 or later awake with the lid closed for one session you start, on AC power by default. Battery use is optional, down to a floor you pick (for example 20%), and a watchdog restores normal sleep if anything stops or hangs. More on how to keep a MacBook awake with the lid closed and on keeping it awake on battery.

To make a sleeping MacBook wake less, each built-in setting has a cost:

  • Enable Power Nap. In System Settings > Battery > Options, where your Mac offers it, Apple lets you choose whether it checks "always, only on battery power, or never" (Battery settings). In Terminal: sudo pmset -b powernap 0 for battery only. With it off, Mail, Calendar and iCloud update when the Mac is awake. More in Power Nap and Wake for network access, explained.
  • Wake for network access. In the same Options, Apple offers "always, when plugged into a power adapter, or never" (Battery settings), and its guide to unexpected wakes says to choose Never (Apple Support). In Terminal it is womp, which man pmset calls the same as Wake for network access in System Settings.
  • tcpkeepalive 0. Costs Find My Mac while the Mac sleeps, by Apple's own warning above.
  • hibernatemode 25. man pmset calls it the setting for "slower sleeps, slower wakes, and better battery life", settable only with pmset, and says "Please use caution" (man pmset).

To see which of these settings your Mac uses now, paste pmset -g into the Mac sleep settings explainer.

Careful: A closed MacBook that is awake still makes heat. Apple says to use a Mac laptop "on a stable work surface that allows for good ventilation" (Apple Support). Never leave an awake Mac in a bag; more in MacBook heat and battery with the lid closed.

Is it safe to paste my pmset log here?

Yes. The tool runs entirely in your browser: the page sends what you paste nowhere, stores nothing, and keeps it out of the site's analytics. Where the site's analytics run, they count that the tool was used, never what you pasted. The filtered log holds times, charge levels and wake codes; the whole pmset -g log also names apps and system services, so read it before you paste it anywhere else.

FAQ

Does a MacBook battery drain in sleep mode?

Yes, slowly. Memory stays powered with the default hibernatemode 3, and the Mac wakes in the dark now and then for Power Nap, maintenance and network or device events. The tool above measures how much from your own pmset -g log.

Why does my MacBook battery drain when the lid is closed?

Closing the lid puts it to sleep (Clamshell Sleep in the log), and a sleeping MacBook still powers its memory and wakes briefly with the display off. If it loses much more than you expect, the tool shows how often it woke and which kinds of wake took the time.

What do dark wakes have to do with battery drain?

Each dark wake runs the Mac for a few seconds with the display off. Many of them add up: the tool shows the dark wakes per hour and the share of the sleep the Mac spent awake.

Should I turn off Power Nap to save battery?

It is your choice: Power Nap wakes the Mac now and then to check for email, calendar and iCloud updates. Apple's Battery settings let you choose always, only on battery power, or never, where your Mac offers it.

Does Keep Mac Awake make a sleeping MacBook use less battery?

No. Keep Mac Awake keeps a MacBook awake with the lid closed for a session you start, which uses more battery than sleep; on battery it runs only if you allow it, down to a floor you pick. Use it when the Mac should keep working, not when it should sleep.

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