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Is it possible/necessary to configure a "Battery is full, remove charger notification" similar to the Low Battery Alert?

I run macOS Sierra on my computer and wonder what software or scripts or configuration is needed to perform this.

[Based on an answer, the question has been modified to include if this is necessary since that was the main intention behind the query]

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  • Welcome to Ask Different. Feel free to edit in some more details as to what the larger goal is. What does full mean to you - when the charge stops? When the charge current goes to trickle? When the menu bar shows 100%? No need to edit if the answers you are getting are on track already.
    – bmike ♦
    Commented Jun 22, 2017 at 13:00

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This is completely unnecessary.

All batteries packs have a something called a battery protection circuit which is designed to disconnect the battery from the charging source once it reaches full capacity and disconnect from the load once it drops to a certain voltage. Below is a photo from a (circa 2007 MacBook) battery that has been disassembled.

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Battery Health Management

With the release of Catalina (10.15.5) this is now even more unnecessary as this "battery preservation" technology is now baked into the OS; it's called Battery Health Management. The way it works is that it reduces the maximum charge while plugged in. The battery icon may show "Not charging" and will discharge to around 93% even with the charger connected before charging again. See Apple Support Document About battery health management in Mac notebooks.

When you overcharge a battery, you could damage it and cause it to burn. Without this protection circuit, at minimum you would be drastically shortening the life of your battery and at worst, starting a fire (thermal runaway).

There is an excellent YouTube video that shows how a protection circuit works through building one. There's also an excellent article on HowStuffWorks; Can your laptop battery be overcharged?

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    The battery protection circuit does not actually disconnect the battery when it is full, it only kicks in in case of an emergency, like the low voltage you cite. The charger, which is a chip outside the battery, but inside the Mac, is responsible to stop charging once the battery is full. If the charger fails, the battery overheats and the internal protection (hopefully) saves it.
    – Vladimir Cravero
    Commented Jun 22, 2017 at 13:46
  • @VladimirCravero What you are refering to is the battery charging circuit which does a lot more than that - it actually regulates the amount of voltage being sent to the battery until it's full or near full when it changes to a "trickle" charge to stopping power delivery altogether. What I am referring to is overcharge protection that's built into the battery pack which will, in fact, disconnect from the source.
    – Allan
    Commented Jun 22, 2017 at 15:27
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Additional software is required.

See Should I disconnect my MacBook Pro's power cord when the battery is fully charged? for a discussion about getting those most from your laptop's battery.

Battery Guardian

Depending on what you want to achieve, Battery Guardian can remind you when to fully discharge a battery.

DssW Battery Guardian

Beyond an Alert

If you want to do more when your battery reaches a specific charge or state, then additional software is needed. One approach is Power Manager, which I am involved with. With Power Manager, you can run scripts and actions based on your Mac's UPS and battery state.

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