Newbie here - battery related question

[johnchristy44]

Hi guys,

Just bought a macbook air 2019 model and im trying to find out how to maintain my battery life. I know there are 1000s of online articles, forum posts etc but im really getting mixed answers/reviews...

From one reliable source i saw that we shuld unplug when its around 100%, then charge again when its 20-30%.. some other sources (websites) / users told me that i can just keep it plugged 24/7 and just need to drain the battery once or twice a month... so which one is true? If i keep it plugged in lets say 10-12 hours daily do you think that will affect the battery? i.e. heat up the battery etc?

Thanks
Chris

 

[MightyGem]

My mid 2012 MBP is now just over 4 years old. It's on 24/7 and on charge for at least 20 hours a day. Its battery cycle count is 553 and it retains 80% of it's original charge capacity.

I also have a 2009 White MacBook that, again, is on 24/7 and on charge 24/7. Its cycle count is 977 and battery condition is 74% of original capacity. Those numbers haven't changed since it went on 24/7 operation two years ago.

It's designed to run on a battery, so just use it and don't worry. It's more likely that you'll decide it's time to get a new laptop before it needs a new battery.

This should tell you all to need to know:
How to keep your MacBook Pro battery healthy for years

 

[ferrarr]

Here is another Apple Support Article, Batteries - Maximizing Performance - Apple

 

[pigoo3]

It really depends on how you use your portable devices. If you're generally not near an electrical outlet...then you got to rely on the battery. If you are near an available electrical outlet much of the time...then it makes sense to be plugged in.

From one reliable source i saw that we should unplug when its around 100%, then charge again when its 20-30%...

This will accomplish one thing...piling up battery cycles on the battery. And of course every battery can only be recharged just so many times before battery runtime on a single charge decreases.

...some other sources (websites) / users told me that i can just keep it plugged 24/7 and just need to drain the battery once or twice a month... so which one is true?

This is the method I generally use. I'm plugged in most of the time...but a couple times/month I run the battery down to like 50%...then recharge. This keeps the battery electrons running in both directions periodically.

If i keep it plugged in lets say 10-12 hours daily do you think that will affect the battery? i.e. heat up the battery etc?

No. When plugged in...the battery is not being charged 100% of the time. The computer has a charging circuit that shuts off charging once the battery gets to 100%. Then the charging circuit doesn't kick back in until the battery drops below 95% (which takes some time since the computer is plugged in).

The battery will actually heat up more when the computer is operated on battery power...since this is when the battery is being used...and battery electrons are flowing.

HTH,

- Nick

 

[MacInWin]

You've received excellent advice from the previous comments. My only $.02 is to second what Nick said. If you are near a mains power supply, use it. I have my MBP on my desk most of the time, plugged into mains power. My mid-2015 battery was replaced by Apple as part of the battery recall for this model, so it's fairly new. The battery was manufactured 470 days ago, has a total of 13 cycles on it, capacity is nearly at design capacity, 99.1%. After two years, all lithium batteries begin to decay, slowly, because of chemical changes internal to the battery. The decline is fairly slow for a few years, then steepens. Using a lot of cycles can shorten the battery. Most recommendations for lithium batteries are to keep the battery above 70% as much as you can. Deep cycles (below 40%) are very hard on the battery, so try to avoid them. Apple used to make a recommendation to run the battery down once a month, but that was not for the battery health. They wanted to recalibrate the measuring circuit to the battery so that the %/time remaining was more accurate.

Basically, use the machine and don't think about the battery much. Near mains? Plug it in! Not near mains? Don't worry about it.

 

[johnchristy44]

Thank you very much all, i really appreciate your detailed replies. Thank you