Plugged in all the time?

[rekhyt]

I've read online that it's generally a bad idea to plug / unplug your Mac(book Air) if you're just going to use it at your desk.

Should I keep it plugged in at night as well?

Thanks in advance.

-R.

 

[DisplacedMic]

ha - i totally beat GGJ to this:


The built-in batteries in the newer Mac unibody notebooks come pre-calibrated and do not require regular calibration like the removable batteries in older Apple notebooks.

Run on battery whenever you need to and plug it in whenever you can. You can plug or unplug any time you need to, regardless of the charged percentage, and you never need to completely drain your battery. Just make sure you don't run on AC power exclusively, as your battery needs to be used regularly to stay healthy.

The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.
Apple Notebook Battery FAQ

 

[Quackers]

Mine is plugged in most of the time. I just let it run on battery once a month or so and then recharge it.

 

[Miltz]

I've used my work laptop the same way, mostly plugged in. It's important to unplug it at least once a month to get the electrons in the battery flowing. In using this method my Acer laptop from 2009 has exactly the same battery life it did when it was new. I plan on doing the same with the MBA, if i can plug it in, I will.

 

[rekhyt]

Ah right so I've really been quite stupid then.

What I used to do is to charge and then unplug when it becomes fully charged (xRepeat cycle).

I'll just keep it plugged in from now on then unless I need to bring it elsewhere.

Currently my MacBook Air says it's fully charged (green light on my MagSafe charger) but it says 98% on the top right Apple bar. Is this a bad sign?

 

[Quackers]

Not at all. It's a laptop and meant to be portable. You've done nothing silly at all imho.

 

[ionjohn]

You should unplug it regularly so the battery stays healthy.

 

[GGJstudios]

Mine is plugged in most of the time. I just let it run on battery once a month or so and then recharge it.

I recommend you unplug more frequently than once per month. Running on battery for a few hours every few days will usually give you better results. Run on battery whenever you need to and plug it in whenever you can. You can plug or unplug any time you need to, regardless of the charged percentage, and you never need to completely drain your battery. Just make sure you don't run on AC power exclusively, as your battery needs to be used regularly to stay healthy.

​

The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.

Apple Notebook Battery FAQ​

 

[jdechko]

Currently my MacBook Air says it's fully charged (green light on my MagSafe charger) but it says 98% on the top right Apple bar. Is this a bad sign?

This is actually a good thing. Batteries need to be exercised occasionally. Apple, in all their data collection, realizes that people often do the same thing you do, which is to never unplug. So the battery will charge to 100% and then discharge slightly (to ~95%) to keep the electrons moving.

It's not exactly what the guys over at Battery University would say (discharge to 40% then recharge), but it keeps you topped off with a relatively full battery.

It's actually worse for a battery's health to keep it at 100% all the time, which is why Apple does what it does.

Anyway, Apple's batteries are rated for 1000 cycles before they drop to 80% of the original capacity. At a rate of 1 cycle per day, that's almost 3 years. Unplug and go outside! 😀

 

[GGJstudios]

This is actually a good thing. Batteries need to be exercised occasionally. Apple, in all their data collection, realizes that people often do the same thing you do, which is to never unplug. So the battery will charge to 100% and then discharge slightly (to ~95%) to keep the electrons moving.

Actually, Apple battery technology is designed to avoid the short discharge/recharge situation that you described. That is why if you plug-in when the battery is already between 93% and 99% charged, it will not charge from that level. When the battery is fully charged, it stops charging and runs on AC power. Only in rare circumstances will it draw power from both AC and the battery, causing the battery to discharge. Of course, a battery will lose charge overtime even if you don't use it, but that is a different issue.

It's not exactly what the guys over at Battery University would say (discharge to 40% then recharge), but it keeps you topped off with a relatively full battery.

I don't recommend getting battery information from generic sites like Battery University, as they do not have information about Apple's proprietary charging system used in its notebooks.

 

[jdechko]

I'm willing to admit that I was somewhat confused in my mind. I remember John Siracusa talking about that on an episode of ATP, and thought that it was a real thing.

However, I won't say that I'm 100% certain that Apple isn't doing something like what I described already. Anecdotally, I've observed battery percentages changing on my Air even though the task bar reports the battery at 100% and the MagSafe light is green. This is with no or minimal user load on the computer (such that the AC adapter should be sufficient). Percentages and time remaining are only estimates.

Also, re: Battery University (also from Siracusa), I wasn't implying that their science is 100% for every battery, but it's generic advice for Li-Po batteries as a whole.