Optimized Battery Charging on Mac: what it does, when to turn it off

Optimized Battery Charging is a macOS setting that learns when you usually unplug your MacBook. When it expects a long stay on the charger, it holds the battery at 80 percent and finishes charging shortly before you need it. You turn it on or off in System Settings > Battery, behind the info button next to Battery Health.

It is on by default, and it is the usual reason a MacBook that has been plugged in all morning sits at 80 percent. For most people the right thing to do with it is nothing. There are a few days when switching it off makes sense, and they are covered below.

What Optimized Battery Charging does

Lithium-ion batteries age a little faster when they spend long stretches completely full, and faster again when they are warm at the same time. A MacBook that lives on a desk, plugged in from morning to evening, spends most of its life in exactly that state. Optimized Battery Charging is Apple's answer to it.

With the setting on, macOS learns your charging routine on the Mac itself: when you plug in, how long you stay plugged in and when you usually leave. When it predicts a long stay on the charger, it charges to 80 percent and waits. As the time it expects you to unplug gets closer, it charges the rest, so the battery is full when you pick the laptop up. Less time sitting full means slower wear over the years.

A few details clear up most of the confusion:

• It doesn't hold at 80 every time. If your routine is irregular, or the Mac doesn't expect a long stay on the charger, it simply charges to full.
• It has to learn first. A new MacBook, or one whose routine has just changed, may go straight to full for a while.
• It is a MacBook setting. Desktop Macs have no battery, so there is nothing to optimize.
• It doesn't give you more hours per charge. It slows the gradual loss of capacity over months and years. Day to day, the only sign of it is a pause at 80.

MacBook charging myths covers the wider question of what does and doesn't wear a battery, including why leaving a MacBook plugged in is fine.

How to turn Optimized Battery Charging on or off

In recent versions of macOS, the ones with System Settings rather than System Preferences:

1. Choose Apple menu > System Settings.
2. Click Battery in the sidebar.
3. Find Battery Health and click the info button next to it.
4. Switch Optimized Battery Charging on or off, then click Done.

When you switch it off, macOS asks whether you mean until tomorrow or for good. Turn Off Until Tomorrow is the one to pick when you only need a full battery for a single day, because the setting comes back on by itself and you don't have to remember it.

On older versions of macOS with System Preferences, the option is usually a checkbox in the Battery pane. Some Intel-based MacBooks also show a separate battery health management option, which aims at the same goal by a different route. If you can't find either, your Mac may not offer the feature, and the rest of this post's advice about heat and charging habits still applies.

Why is my MacBook stuck at 80 percent?

If your MacBook has been plugged in for hours and the charge is sitting at 80, that is almost always Optimized Battery Charging doing its job. Open the battery menu at the right of the menu bar. It should say charging is on hold, and offer Charge to Full Now. Choose it and the Mac charges to full straight away, just this once. The setting itself stays as it was.

Close to full, the same menu can also say Battery Is Not Charging. That is usually normal too: rather than topping up constantly, macOS often lets a full battery drift down a little before charging it again.

If the menu says nothing about a hold, the charge is well below 80 and the number isn't rising, something else is going on, such as the charger, the cable, heat or the battery itself. MacBook plugged in but not charging walks through those checks in order.

Should you turn off Optimized Battery Charging?

For most people, no. The feature costs you nothing on a normal day, and it helps most in the situation where people are tempted to turn it off: a laptop that is almost always plugged in.

That last row is the real case for switching it off. If you work shifts, travel a lot or keep no regular pattern, the Mac's guesses about when you will unplug will often be wrong, and you may keep picking up a laptop that isn't full. Turning the feature off means a little more time at full charge and so a little more wear over the years. It won't ruin a battery. Plugging in earlier, or using Charge to Full Now on the days it matters, is the gentler fix if you would rather keep it.

Keep the scale in mind, too. The feature trims a little wear each day, and that adds up over years. It is not a switch that decides whether your battery survives.

What it doesn't do

• It isn't a charge limit you pick. The setting has no slider or number to choose. macOS decides when to hold, and 80 is the level it holds at.
• It isn't Low Power Mode. Low Power Mode, also in System Settings > Battery, cuts energy use to stretch a charge. It doesn't change how the battery charges.
• It doesn't protect against heat. Heat matters more than the top end of the charge. Charge on a desk or table, not on a bed or a cushion, keep the vents clear and don't leave the Mac in a hot car or in full sun. Apple advises avoiding ambient temperatures above 95° F (35° C).
• It doesn't repair a worn battery. If Battery Health in the same panel says Service Recommended, the battery has lost a good share of its capacity already. Optimized Battery Charging can slow what comes next, not undo what happened. MacBook battery health explained covers what each reading means.

Where Notchpals fits

Notchpals leaves the top end of the charge to macOS. It has no charging setting of its own and never tells you to unplug at 80 or to charge to full. Its Tech care characters (Juice, Gumdrop and Otto) only speak up at the other end: when your MacBook drops below 20 percent while it isn't on power, and again, more urgently, below 8. That is the one moment in the battery's day when you need to do something.

Plug in after one of those warnings and Juice, a battery who takes a low charge very personally, gets one more line:

JuiceOh, that warm tingle. Thank you, darling. Truly. Deeply. Dramatically.

After that, as long as the Mac is on power, there is no battery talk at all, whether it is charging, holding at 80 or full. So switching Optimized Battery Charging off for a trip, or choosing Charge to Full Now, changes nothing in the notch.