Accidentally left Macbook Pro Retina charging overnight?

The battery is rated for about a thousand discharge cycles, there's nothing you can do to change that. One cycle means a discharge from 100% to the point where the machine shuts itself down, and then a charge back to 100%. If you drop to 50% and fully charge, then do the same again, that counts as one cycle. Doing 10 lots of dropping to 90% and fully charging, would also count as one cycle.

You should use the laptop as fits you. If you are in a situation where you can charge, do. If you can't charge, just use the laptop on battery power and do awesome things with it 🙂

Leaving the laptop on AC power after it is fully charged will not harm the battery. You'll note the MagSafe connector has an LED - if it's green, the battery is not being charged, the computer is being powered directly by the magsafe power, the battery is doing nothing. Leaving it connected, particularly if you are using the laptop, is very sensible at this point. You are preventing the laptop from having to discharge the battery at all, so you're not using any of your battery cycles while at 100% on AC.

It is a good idea to do a complete discharge (i.e. to the point the laptop shuts itself down) every month or so, if it doesn't happen in your normal use. This allows the battery controller to know the full performance of the battery. There are no memory effects in modern LiIon batteries, but if the controller doesn't ever see the performance below 40%, it can't accurately estimate remaining charge.

Apple has some more information at: https://www.apple.com/uk/batteries/notebooks.html

It's completely normal for the battery to perform worse as it ages, it's a sad fact of the chemistry involved. Keeping the battery controller calibrated with the monthly full discharge will improve the accuracy of the battery life predictions, but it won't extend the battery life in any physical sense.

Finally, if you want to track the performance of your battery over time, I would suggest using coconutBattery. I run it once a month after my 1st of the month full discharge and recharge, and tell it to save the data, allowing me to graph my battery over time 🙂

Yes... I do agree with you.

For Li-ion the most important is, time to time, make the ions circulate inside the battery, I mean use without the power connected.

Check here: https://www.apple.com/uk/batteries/notebooks.html

Specifically here:

Standard Maintenance

For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable computer plugged in all the time. An ideal use would be a commuter who uses her notebook on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once a month. Need a reminder? Add an event to Calendar on your desktop.

Have a good day!

Over time if you keep your mac charging when it is at 100% it does lose battery power, but it is not noticeable depending on how often you do it. Leaving it plugged in does not benefit anything. Also do not determine its battery power for what it claims when you click on the icon (ex: 7 hours) because it is usually false - buy the battery health app.

Not to worry - there's no way to overcharge your battery: just keep it plugged up when you're not using it on battery. Other than that you seem to be practicing good habits to maintain a healthy battery. Just don't let your machine shut down because of a completely drained battery and never try to 'calibrate' your battery - that's not necessary with modern Li-Ion batteries.

Good luck,

Clinton

MacBook Pro (15” Late 2011), OS X Yosemite 10.10, 16GB Crucial RAM, 960GB M500 Crucial SSD, 27” Apple Thunderbolt Display

cmsj

Some of your information is simply wrong - you should NEVER completely discharge a modern Li-Ion battery, That's a sure way to shorten battery life.

There are so many conflicting documents from Apple available because they discuss notebook batteries going far back - someone, I suppose, should write a defenative user tip about how to use batteries in up-to-date, current models of the MacBook Pro.

But please don't make statements that are wrong unless you choose to stand behind statements that are wrong.

Clinton

MacBook Pro (15” Late 2011), OS X Yosemite 10.10, 16GB Crucial RAM, 960GB M500 Crucial SSD, 27” Apple Thunderbolt Display

Clinton

Nope nope nope nope nope 🙂

It is true that chemically a LiIon battery is harmed by being *completely* discharged, but you'll note that I recommended two things:

* monthly discharge cycle

* discharging to the point the machine shuts itself down and then charging back up to 100%

The first of these ensures that the battery controller understands the current state of the chemistry.

The second *does not completely discharge the battery*. It discharges to the point the battery controller believes is the minimum safe level, and then shuts the machine down. Because you're doing this monthly, the controller is able to accurately gauge where that minimum point is, and then you take the battery back up to 100%.

What I said was not wrong at all, and is exactly in line with Apple's very own recommendations. Please read the link I posted, you will see this is exactly what they recommend. They even specifically call out the physically-complete-discharge issue in the long term storage guide for macbooks (which is to store at 50%).

That's what I'm saying about Apple's recommendations - there are many documents out there and you have to be judicious in deciding which of the conflicting advice you should follow.

You should never, never let your battery drain down to the point where your machine shuts down. That's like the old concept of 'conditioning' your battery - something that damages modern Li-Ion batteries. At most, you should get to an outlet when you run down to around 10% or so. I've read the link that you posted many, many times and part of it is simply out-of-date.

Do some research on current Li-Ion batteries used in notebook computers. You'll not find anything recent suggesting that you should discharge the battery to the point where the computer shuts down.

Clinton

MacBook Pro (15” Late 2011), OS X Yosemite 10.10, 16GB Crucial RAM, 960GB M500 Crucial SSD, 27” Apple Thunderbolt Display

I would note that many of the scary scary things online about batteries are talking about Lithium Polymer batteries, not Lithium Ion ones. The smart controller in the laptop will shut it down before the battery is fully exhausted. This isn't about conditioning the cells, this is about calibrating the "gauge" on the controller.

I'm done arguing about this, I follow Apple's advice and my batteries are in great shape. I have a 2.5 year old rMBP at 89.1% capacity and a 7 month old rMBP at 100% capacity. Seems to work well for me 🙂

Hi Jupiterbrazil, I have a new MacBook pro Retina 2013 Early. Do i need to use the Battery at all? I am always leaving it connected to the power and I use a DISPLAY to view so my lid is always closed. Is it ok to just use POWER all the time? or do i need to run the battery down sometimes? I have already had to replace a battery in my 2008 MBP Late Oct. $129.00 USD

Hi

Well it seems you can over charge a macbook pro.

My charger seemed to have stopped working and the laptop wouldn't turn on.

I went to apple care and checked the charger on their macbook and it was okay but my mac had shut itself down. Apple told me "If the light on the charger is yellow then its charging when it turns green its fully charged and should be removed."

I have had 1 charger burnout and this is the new charger so i was sure it was that, that was faulty.

So take your choice.

cmsj,

I'll have to agree with you on this... my 5 year old (to this day) 15" macbook pro currently reads 85.1% design capacity for the original battery installed. I'd have to say that is pretty darn good for a five year old battery. I rarely unplug the unit except an occasional full discharge (determined by the system) and maybe only four or five times a year.

That's just nonsense.

Clinton

MacBook Pro (15” Late 2011), OS X Yosemite 10.10, 16GB Crucial RAM, 960GB M500 Crucial SSD, 27” Apple Thunderbolt Display

The machine will not overcharge itself. I wouldn't worry about it. If you are worried about it, Just remember, it only happened once.

Good luck.