Fully Charged MacBook Loses Charge Without Use

Hi everyone,

I have a 2020 MacBook Pro (M1) and noticed something strange. Yesterday I charged it to 100%, then shut it down and stored it in my backpack overnight.

This morning, when I turned it on, the battery was at 95%.

Is this normal behavior? I’m wondering if it’s due to natural self-discharge, background processes, or macOS’s “Optimized Battery Charging” feature.

My battery health is at 89%, cycle count is around 133, and I usually keep it plugged in when working.

Has anyone else experienced this? Is there any way to prevent it from dropping when the MacBook is completely shut down?

Thanks in advance for your insights!

Device details:

• MacBook Pro (M1, 2020)

• macOS version: Sequoia 15.6

• Battery health: 89%

• Cycle count: 133