Battery at 100% bad?

[That 1 Guy]

Will keeping a laptop battery constantly at 100% harm the battery or shorten its lifespan?

 

[R_1]

what will shorten the lifespan is leaving the battery in while on AC all the time. if the laptop does not move from the desk, remove the battery. when you do actually need the battery put it in unplug the computer and go. the constant charging can wear the battery life down. even if you never unplug it and use the battery.

 

[That 1 Guy]

What if I use the laptop while plugged and unplug when done?
And don't li-ion batteries stop charging when they're full?

 

[R_1]

yes they stop when full. then in standby they start to drain a bit, the charger detects this and tops off the battery. 1% here, 2% there, rinse, repeat. a year or two of this will kill a battery, even though it is never unplugged and the battery was never actually used. I suggest charging the battery when the pc needs to be mobile, and when storing in work location remove the battery. long periods, weeks plugged in, months plugged in etc.

 

[That 1 Guy]

Is there a program or something for MacOS that stops charging the battery even if it is plugged in?

 

[That 1 Guy]

I found something even better:

If I charge the battery to 50% then put a peice of tape on the middle prong of the Magsafe 2 connector, the Mac will not charge but still be supplied power via the AC adapter.