Why does the battery drain so fast on my Galaxy Book5 Pro 360 when its fully turned off? It will be on 80%(because it stops at 80% to save the battery life) then not even 2 days later when I turn it on the battery is ~55%.
It's possible that some background tasks are running which contribute to the loss of battery. Let's go ahead and backup your device first before doing any troubleshooting to ensure you don't lose any of your content. I'd check for any background activity occurring and make changes to that.
We understand completely the frustration a draining battery can cause especially with the computer being turned off. We would love to assist and ask have you tried our function called Smart Battery Calibration? This helps reset your battery's performance and can even recalibrate its minimum and maximum charge, so you can achieve its maximum capacity.
If you have this option for your specific device; please follow these steps to enable this function:
1. Select Advanced on the left-side menu
2. double-click Smart Battery Calibration on the right-side menu.
3. The battery will be discharged by the PC.
*** The process may take up to 5 hours depending on the capacity and remaining battery life.
4. To cancel the operation for any reason, press the ESC key.
We obtained this information from our article Battery Life on Samsung PC and encourage you to review it as well for further assistance if needed.
If you are certain the device was fully shut down rather than in sleep or standby mode, then a drop from 80% to 55% over two days is indeed excessive. You might first try updating the BIOS, Windows, and drivers via Samsung Update, and then run a test with all peripherals disconnected. If significant battery drain persists after a full shutdown, it is recommended that you contact Samsung Support to have the battery and motherboard inspected.
That much drain while the laptop is fully shut down doesn't seem normal. I'd first make sure Fast Startup is disabled and check for any BIOS or Samsung firmware updates. Also try shutting it down completely, then leave it unplugged overnight and see how much the battery drops. If it still loses 20%+ while fully powered off, I'd have the battery checked since it could be a battery or power-management issue.
Check Fast Startup/Modern Standby, update the BIOS and Samsung drivers, and shut it down with all USB devices disconnected. If it still loses ~25% in two days while fully powered off, run a battery health report—at that point, it may be a firmware or battery issue.
HawksTV
Halo
08-12-2026 11:34 PM
in
Samsung_Moderator
Community Manager
08-13-2026 02:10 PM
in
Hello OohGotty,
We understand completely the frustration a draining battery can cause especially with the computer being turned off. We would love to assist and ask have you tried our function called Smart Battery Calibration? This helps reset your battery's performance and can even recalibrate its minimum and maximum charge, so you can achieve its maximum capacity.
If you have this option for your specific device; please follow these steps to enable this function:
1. Select Advanced on the left-side menu
2. double-click Smart Battery Calibration on the right-side menu.
3. The battery will be discharged by the PC.
*** The process may take up to 5 hours depending on the capacity and remaining battery life.
4. To cancel the operation for any reason, press the ESC key.
We obtained this information from our article Battery Life on Samsung PC and encourage you to review it as well for further assistance if needed.
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ceciliazhu
Halo
08-14-2026 01:39 AM
in
If you are certain the device was fully shut down rather than in sleep or standby mode, then a drop from 80% to 55% over two days is indeed excessive. You might first try updating the BIOS, Windows, and drivers via Samsung Update, and then run a test with all peripherals disconnected. If significant battery drain persists after a full shutdown, it is recommended that you contact Samsung Support to have the battery and motherboard inspected.
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DFWTechGuy
Cosmic Ray
08-14-2026 05:43 PM
in
That much drain while the laptop is fully shut down doesn't seem normal. I'd first make sure Fast Startup is disabled and check for any BIOS or Samsung firmware updates. Also try shutting it down completely, then leave it unplugged overnight and see how much the battery drops. If it still loses 20%+ while fully powered off, I'd have the battery checked since it could be a battery or power-management issue.
jasonmiller11tt
Cosmic Ray
08-17-2026 04:54 AM
in
0 likes