Does leaving MacBook plugged in use the battery?

Macintosh116 wrote:

I see. The bit about how it constantly drops below 100% and recharges concerns me because it means it’s always degrading the battery. It seems there’s nothing I can actually do to preserve battery health. It frustrates me that there’s no way to prevent the battery from being used like there was on my old laptop.

You don't appear to understand or accept what you are being told.

• You can leave the computer plugged in without damaging the battery.
• It is not a good idea to remove the battery (now or on your old PC)
• The computer will not perform as designed if you remove the battery.
• Battery cycles are cumulative meaning the trickle charge will have very little impact.
• Unplugging the computer during use will cause the rate of discharge to increase and therefore impact battery cycles
• The computer has protective circuitry that will prevent overcharging.
• The computer will slow down if you remove the battery.
• Leaving the computer plugged in preserves battery health by reducing the rate of accumulating battery cycles.

So the benefits associated with leaving the battery in and connected to power far outweigh the negatives associated with removing the battery. Do not remove your battery.

Just adding to what other said, if it's left plugged in all the time it will charge up to "100%" then slowly any self-discharge or supplemental power needed from the battery will drain the battery. The battery indicator will say "Battery Is Charged" but there will still be a lightning bolt over the battery symbol. The moment it drops below 95% it will start charging again.

If you somehow removed the battery, what it will usually do is throttle the CPU to avoid the possibility of using more power than the power adapter can supply. If it tried to use more than the supply can give you'll end up with a sharp voltage drop and everything just shuts down immediately. I've done this before on an older Mac with a user-removable battery. It still works, but everything slows down a bit. I'd see an X on the battery symbol.

Apple used to display it a different way. When it hit the point where it reached 100% and stopped charging, there would be a symbol that looked like a North American power plug inside the battery symbol. Now it always has the lightning bolt inside there regardless of whether or not it's charging the battery.

You can leave the computer plugged in. There is no advantage to removing the battery. There wasn't any advantage to removing the batter on your PC. If you remove the battery or in some other way bypass the battery the computer will not perform as designed.

Macintosh116 wrote:

I see. The bit about how it constantly drops below 100% and recharges concerns me because it means it’s always degrading the battery. It seems there’s nothing I can actually do to preserve battery health. It frustrates me that there’s no way to prevent the battery from being used like there was on my old laptop.

To see how much you are obsessing over something so unimportant, do the following. Make sure your computer is fully charged before you go to bed and then unplug it and put it to sleep. In the morning see how far the battery has discharged...that is exactly how much your battery would have recharged overnight so that it would be fully charged for you in the morning. Of course one night won't give you the full picture since the computer will automatically wake itself periodically to check for mail, perhaps download updates from Apple, and back up the hard drive. Some nights will see more drain than others but it will be typically be somewhere between 1% and 3%. In other words, in the course of a year, at worst, keeping the computer plugged in while you aren't using it will, at worst, put 12-14 extra cycles on your battery. At that rate age is going to have a bigger impact on your battery's life than recharge cycles.

This is a highly 'charged' topic ... pun intended.

There is so much folklore around this. You're battery will charge to 100% stop charging and then recharge between 95%-100%. If you leave it plugged in all the time, ensure you have a surge protector in there somewhere.

https://www.apple.com/batteries/maximizing-performance/

Newer batteries don't need to be exercised like the NiCad batteries used to.

Apple once had a very detailed article posted regarding its Li-polymer notebook batteries but apparently though we were too dumb to absorb it and pulled it. It stated that, should the computer be on wall power and encounter a task that demanded more power, it could draw that power from the battery to supplement wall power.

The last Mac notebook that used NiCads was the PowerBook 150, discontinued in April 1996. Then they used nickel metal hydride (NiMH) batteries on some model but by early1997 were using exclusively lithium batteries.

Macintosh116 wrote:

I see. The bit about how it constantly drops below 100% and recharges concerns me because it means it’s always degrading the battery. It seems there’s nothing I can actually do to preserve battery health. It frustrates me that there’s no way to prevent the battery from being used like there was on my old laptop.

Any use of a battery degrades it. In the end this is creating less reduction in capacity compared to disconnecting the power adapter and allowing it to be used on battery power. The battery is also needed to have full capabilities. A battery can supply considerably more peak current than the power adapter is capable of supplying.

Sure there is "degradation" but it's extremely mild.

Exactly what were you looking to do with a battery taken out? The new Mac notebook computers have batteries that are glued in place. There's probably nothing worse for a battery than to have it sitting on a shelf self-discharging. Leave it there long enough and it's going to reach a self discharge state. "New old stock" lithium batteries that have been sitting around for years often have reduced capacity. A battery just stored somewhere isn't good for it's "health" either.