User level: Level 1 (4 points)Is it safe to leave my MacBook Pro 2019 16" (intel) with battery needing service plugged in for charging all day?
Posted on Oct 24, 2026 11:40 AM
User level: Level 10 (148,617 points)Oct 24, 2026 12:35 PM in response to Started1987
The CHARGER is inside the MacBook Pro, and is completely under program control. Your Mac accepts some power when needs to run, and accepts more power when it intends to charge its internal battery. A power source like the Power Adapter or certain Displays can not 'force itself' on your MacBook Pro. Only the algorithms inside your Mac can decide when is a good time to charge the battery. Your Mac can NEVER be over-charged.
In general, you should ALWAYS connect a power source when it is possible to do so, and only run on batteries (which could be somewhat slower) when no power sources are at hand. Modern Macs maintain optimum battery charge levels under program control, and will NEVER over-charge. Connected to Power is NOT necessarily charging.
User level: Level 7 (27,833 points)Oct 24, 2026 1:57 PM in response to Started1987
Started1987 wrote:
Is it safe to leave my MacBook Pro 2019 16" (intel) with battery needing service plugged in for charging all day?
Yes, it's safe ... unless the battery is swelling, which is a big red flag that needs to be attended to immediately. A swollen battery is a fire hazard.
If you know the battery needs service, you should get it serviced.
User level: Level 10 (87,747 points)Oct 24, 2026 11:44 AM in response to Started1987
Started1987 wrote:
Is it safe to leave my MacBook Pro 2019 16" (intel) with battery needing service plugged in for charging all day?
Yes it is safe to leave your Mac plugged in. Doing so will not harm the battery or the computer.
Oct 24, 2026 12:06 PM in response to Started1987
Yep. Go ahead. Won’t harm the battery at all.
User level: Level 10 (85,896 points)Oct 25, 2026 12:01 PM in response to Started1987
Battery swelling can cause irreparable damage if not immediately addressed. Here's the checklist I made for testing when a swollen battery is suspected:
— Unexpected trackpad and/or keyboard behavior.
— The gap between the display and the deck is not even when the display is closed.
— The gap between the bottom plate and chassis is uneven in places.
— Some of the screws that hold the bottom plate have popped out.
— The trackpad surface is higher than the surrounding deck surface.
— The computer "rocks" a bit on a known flat surface†.
............
† I find solid-surface (quartz or porcelain) and granite countertops very effective flat test surfaces. Tiled or Formica countertops don't work well for this.
Originally posted at discussions.apple.com/thread/256382246