View Full Version : When do I keep my MacBook Pro plugged in

07-26-2017, 09:48 AM
Just recently bought a new 15" MacBook Pro w/touch bar. As everyone knows, it's a huge (but worth it) investment so I'm trying to learn as much as I can to prolong the life of this computer.

I have a question about the battery, is it harmful to keep the charger plugged in at 100%? or are there mechanics that divert the power straight to the power supply and stop charging the battery when it reaches a full charge. I know this is the case with some computers, but wasn't sure if Mac OS had this implemented yet. Just need some verification, also if there are any other tips to prolonging my computer at the top of your head, please let me know! :D

Thanks in advance.

07-26-2017, 10:04 AM
Welcome to the forum.

In short, you can keep the MBP plugged in all the time (I do that here) that you have it available. It won't hurt the battery. The LiIon battery in your MBP is happier if you keep it topped off, avoid deep discharges as much as you can. Other than that, to prolong your MBP we would recommend keeping liquids away from your work area and that's about it. You don't need antivirus, cleaners, helpers, boosters, or any other stuff to really keep the MBP going. Just reboot it once every couple of weeks to clear up the cache that builds up and leave it running overnight so that the built-in utilities can clean up the system while you sleep. My MBP is plugged in 99% of the time, and I just let it go to sleep at night, almost never actually power it off.

Now the long story: Unlike older technology (NiCad, NiMH, etc) battery, the Lithium Ion battery does not have issues with needing to be discharged to avoid developing "memory" issues. In fact, the technology is more limited by what are called "cycles" of the battery. Your battery will start to show decreasing capacity after about 500 cycles. A cycle is a move of the battery from 100% charged to fully discharged and then back to 100% charged. Partial cycles don't exactly add up, but for most of us we assume that two 50% cycles equals one full cycle. The best way to keep your MBP happy is to keep the battery between 40% an 100%, preferably above 60% if you can. That is considered "light" use of the battery and will give the longest life. That said, ALL LiIon batteries begin to decay slowly at two years after manufacture. That decay has to do with the chemistry inside the battery and is true of ALL LiIon batteries, not just Apple's. However, that age decay is very slow at first, so it's not generally an issue, just something to know for the future, say 4-5 years from now when your battery may only have 90% of the capacity it has now, even if you treat it very well.

But the idea of a MBP (and all portables) is to be able to use it where and when you want, so if you need to run the battery down, go ahead and use the MBP. That's why you bought it in the first place. The battery should last the life of the MBP even if you do occasionally drive it hard.

If you want to monitor the health of your battery, I would recommend CoconutBattery. It can give you just about everything you ever wanted to know about your battery. You can get it here: http://www.coconut-flavour.com/coconutbattery

07-26-2017, 11:59 AM
Also, here is Apple's info about their batteries, with links to keep them healthy, etc...