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How do I best preserve my battery?

So I have a new MacBook Pro Retina 13", and I was wondering, something I have always wondered... how do i preserve the battery life of my mac best?

Some people say you should let it run out of battery (almost) and then recharge until 100% and then unplug again until almost empty, and so on... (I am not sure if this is right or not, if it won't use up all the battery cycles too fast, etc.)

Some other people say that when you work on a desk for a long time it is best to leave your mac plugged in all the time, only unplug when needed (with, of course letting the battery uncharge once or twice a month and recharge), but other say you should not let your battery plugged when it's already full cause it will damage it.

And finally I have heard you should never ever when possible let it drain only partially and the charge only partially, it should only be charged when almost empty and should charge until full... (although there is other oppinions that say this doesn't matter)

So as you see, pretty much every opinion I have read contradicts the other ones, so... anyone who can explain me how this works really?

And... I have only used my macbook for 5 days and on CoconutBattery it already says Design Capacity - 6600 mAh Current Capacity - 6432 mAh (97%). How is this possible? It already lost 3% of its capacity in 5 days of use!?

I appreciate your answer enormously. 🙂

MacBook, Mac OS X (10.6.8)

Posted on Nov 5, 2013 3:18 PM

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Question marked as Best reply

Posted on Nov 5, 2013 3:24 PM

yaozilan wrote:


Some people say you should let it run out of battery (almost) and then recharge until 100% and then unplug again until almost empty, and so on... (I am not sure if this is right or not, if it won't use up all the battery cycles too fast, etc.)


Very bad advice.


Some other people say that when you work on a desk for a long time it is best to leave your mac plugged in all the time, only unplug when needed (with, of course letting the battery uncharge once or twice a month and recharge),

Good advice. Let it run down to about the 40% level and then recharge.


but other say you should not let your battery plugged when it's already full cause it will damage it.

Totally false. The Mac OS will not allow a battery to be overcharged.


And finally I have heard you should never ever when possible let it drain only partially and the charge only partially, it should only be charged when almost empty and should charge until full... (although there is other oppinions that say this doesn't matter)

Nonsense.


Read some of these articles from Apple for authoritative information:


http://www.apple.com/support/macbookpro/batteries_power/


Ciao.

8 replies
Question marked as Best reply

Nov 5, 2013 3:24 PM in response to yaozilan

yaozilan wrote:


Some people say you should let it run out of battery (almost) and then recharge until 100% and then unplug again until almost empty, and so on... (I am not sure if this is right or not, if it won't use up all the battery cycles too fast, etc.)


Very bad advice.


Some other people say that when you work on a desk for a long time it is best to leave your mac plugged in all the time, only unplug when needed (with, of course letting the battery uncharge once or twice a month and recharge),

Good advice. Let it run down to about the 40% level and then recharge.


but other say you should not let your battery plugged when it's already full cause it will damage it.

Totally false. The Mac OS will not allow a battery to be overcharged.


And finally I have heard you should never ever when possible let it drain only partially and the charge only partially, it should only be charged when almost empty and should charge until full... (although there is other oppinions that say this doesn't matter)

Nonsense.


Read some of these articles from Apple for authoritative information:


http://www.apple.com/support/macbookpro/batteries_power/


Ciao.

Nov 5, 2013 3:42 PM in response to yaozilan

Just make certain that about once a month to use it under battery power to the 40%± level and then recharge.


Now there may be times when you have to use it under battery power and you do not have access to AC. If you get the warning, 'you are now operating under reserve power', terminate your session. It is not 'ideal' for the battery, but it will not destroy it either. Just do not do that all the time.


Ciao.

Nov 5, 2013 3:59 PM in response to yaozilan

Keep it plugged in when near a socket so you keep the charging cycles DOWN on your LiPo (lithium polymer) cells / battery.


*Contrary to some myths out there, there is protection circuitry in your macbook and therefore you cannot 'overcharge' it when plugged in and already fully charged

You certainly CAN leave your macbook plugged in all the time, take it off charge and drain the battery down to 15 or 20% every couple of weeks or so.


*However if you dont plan on using it for a few hours, turn it OFF (plugged in or otherwise), ...*you dont want it both always plugged in AND in sleep mode


LiPo (lithium polymer, same as in your macbook) batteries do not need conditioning. However...


LiPo batteries do NOT like to be dropped down to 15% or so often,....key word being "often"


A lot of battery experts call the use of LiPo cells the "80% Rule" ....meaning use 80% of the charge or so,.. then recharge them for longer overall life.


Never let your Macbook die from power, you can corrupt files that way, and the batteries do not like it.



The only quantified abuse seen to LiPo cells is instances when often the cells are repeatedly drained very low.


*Also, if youre going to store your macbook away for a few weeks or more,... make sure it has at least a 50% or so charge.


*Cycle count / use/ lifespan is one thing that cant be countered.



Proper treatment is another thing. Just because LiPo batteries dont need conditioning in general,.. does NOT mean they dont have an ideal use / recharge environment. Anything can be abused even if it doesnt need conditioning.


Just use and enjoy your new macbook,


From Apple on batteries:

http://www.apple.com/batteries/notebooks.html


http://support.apple.com/kb/HT1446


but really all you would keep in mind is --"consider 15-20% is the same as 0% and recharge it"


and best "tip" is if its near a socket, .....plug it in as long as you can (especially at home) since cycle count on the battery are the "miles that wear out the tires (battery)"



Important useful info on your Lithium cells as compiled from battery experts:


Heat increases battery performance but shortens life by a factor of two for every 10°C increase above 25–30°C (18°F above 77–86°F). This is yet another important reason for the cooling of any notebook, not just keeping the processor and GPU cool. Mavericks lower power tasking (app nap) and combined with the cool running Haswell processor both greatly protect battery life on your Macbook now more than ever before.


Good news: *Mavericks not only increases a single charge cycle for longer battery use off a full charge,… but also prolongs the overall long term life of the LiPo battery in a Macbook by reducing the load conditions the battery experiences from heavy peak-use.


Counting cycles is not conclusive because a discharge may vary in depth and there are no clearly defined standards of what constitutes a charge cycle on a Lithium Ion battery empirically. Similar to a mechanical device that wears out faster with heavy use, so also does the depth of discharge (DoD) determine the cycle count.


The shorter the discharge (low DoD), the longer the battery will last. If at all possible, avoid full discharges and charge the battery more often between uses. Partial discharge on Li-ion is fine.


Frequent HIGH depth of discharge rates (draining the battery very low) on a Lithium battery will hasten the lowering of maximum battery capacity.


Although better performing when warm, lithium polymer batteries live longer when kept cool.


Lithium cells prefer draining conditions at a steady pace rather than fast pulsed or quick discharges, …this fact is idealized now with the Haswell and Mavericks app-nap low power tasking for battery use.


App nap:

http://www.apple.com/osx/advanced-technologies/


😊

Nov 5, 2013 4:10 PM in response to PlotinusVeritas

Thanks a lot for the valuable info. Now I am out and away from the old myths and start understanding how this really works. ^^ Awesome!

Although I don't have Mavericks (one week short of the release of the new mac, was in a hurry), I am guessing it also counts for the previous version (how the heck do I know what it is? I think it's supposed to be Mountain Lion, but am not sure...)

Again. Thanks!

How do I best preserve my battery?

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