Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

MacBH928

macrumors G3
Original poster
May 17, 2008
9,166
4,193
I have MBP 2015, it had 13% charge so I closed it so it will go to sleep. I switched it on today and the battery is dead.

1) If my iphone battery dies everything runs just as good, but I am under the impression if a macbook/computer battery dies during sleep the system get corrupted or malfunctions. Can any one elaborate?

2)Why did the battery die so quickly? I thought at 10% it should last like 2 hours running but the battery died/drained while it was sleeping/hybernating (I closed the lid). The MBP is brand new and this was its second full charge to drain (2 cycles).
 
1) No, your Mac will work as normal.
2) Fully charging and discharging your Mac negatively impacts battery life nowadays. Do not do it, just use your Mac normally.
 
  • Like
Reactions: Weaselboy
I don't know how accurate the percent remaining figure is, so that could be an issue here. But more likely, depending on how you've got things set up, your computer may wake during sleep to update, check messages, etc. There are threads here about how to avoid that if you don't want it to happen.
 
2)Why did the battery die so quickly? I thought at 10% it should last like 2 hours running but the battery died/drained while it was sleeping/hybernating (I closed the lid). The MBP is brand new and this was its second full charge to drain (2 cycles).

I have a lithium ion battery for my outboard(a Torqeedo). They usually suggest that the battery will do fine down to about 10-15 % but that you shouldn't try to run it down below that if you want to keep battery life. Lithiums don't have the memory effect of other older batteries, so running it down to 30% is not a big deal. But running it below 15% can. Don't believe the memory meter. Its very difficult to measure the actual charge on the battery; its all estimates since the actual charge cannot be measured. Google this if you want.
 
1) No, your Mac will work as normal.
2) Fully charging and discharging your Mac negatively impacts battery life nowadays. Do not do it, just use your Mac normally.

I have a lithium ion battery for my outboard(a Torqeedo). They usually suggest that the battery will do fine down to about 10-15 % but that you shouldn't try to run it down below that if you want to keep battery life. Lithiums don't have the memory effect of other older batteries, so running it down to 30% is not a big deal. But running it below 15% can. Don't believe the memory meter. Its very difficult to measure the actual charge on the battery; its all estimates since the actual charge cannot be measured. Google this if you want.

So we no longer have to do battery calibration? There was a method where you charge your battery fully, run it down, keep it dead for 5 hours, then fully charge again.

Its supposed to refresh you battery to give it extended life and give better charge reading.
 
So we no longer have to do battery calibration? There was a method where you charge your battery fully, run it down, keep it dead for 5 hours, then fully charge again.

Its supposed to refresh you battery to give it extended life and give better charge reading.

That damages modern day batteries - or rather, runs the risk of.
 
  • Like
Reactions: Weaselboy
Do you have some credible source material for that? I have NEVER heard anything other than "drain once a month to calibrate and extend longevity"

If this is dated info, it would be extremely time saving, but must have sources.

You know what they say: "trust but verify"
 
Do you have some credible source material for that? I have NEVER heard anything other than "drain once a month to calibrate and extend longevity"

If this is dated info, it would be extremely time saving, but must have sources.

You know what they say: "trust but verify"
Here is the current Apple battery info. They no longer have anything on there about calibrating the battery.

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

https://support.apple.com/en-in/HT204054

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

I think you might be thinking of this old info on battery calibration where they did suggest it on older MacBooks with removable batteries. But the article says not to do it on newer MacBooks with non-removable batteries.

https://support.apple.com/kb/PH14087

If your portable Mac has a built-in battery, you don’t need to calibrate the battery.

Based on this and the earlier information on battery cycles, if you are running down the battery on purpose once a month to calibrate it, you are using up one full battery cycle and likely reducing the life of the battery.
 
  • Like
Reactions: CoastalOR
Based on this and the earlier information on battery cycles, if you are running down the battery on purpose once a month to calibrate it, you are using up one full battery cycle and likely reducing the life of the battery.

So now the calibrating the battery actually hurts and not help the battery life, and its better to keep it always on charge?

How are the new non-removable batteries different than the removable ones?
I imagined it was the same thing, kind of like how they had removable SSD and soldered SSDs but its basically the same thing.
 
So now the calibrating the battery actually hurts and not help the battery life, and its better to keep it always on charge?

How are the new non-removable batteries different than the removable ones?
I imagined it was the same thing, kind of like how they had removable SSD and soldered SSDs but its basically the same thing.
Correct... you are using up charge cycles needlessly if you run down your battery on purpose to calibrate it. Just leave it plugged in if you don't need to be portable and don't worry about it.

I have no idea how the battery chemistry changed, I just know the Apple guidelines changed.
 
  • Like
Reactions: Samuelsan2001
Interesting.

So what would be the recommended % to plug in the charger? I always run down my iPhone battery, so now I'll likely change that habit.
 
I can leave my MBP plugged in at 100% for as long as I want without damaging it (reducing its life)? I've always been told the opposite with laptop batteries.
It will not hurt a thing. Once it reaches a full charge, it will stop charging to prevent overcharge and damage. It has circuitry built in just to manage this.
 
  • Like
Reactions: meteoreos
So now the calibrating the battery actually hurts and not help the battery life, and its better to keep it always on charge?

How are the new non-removable batteries different than the removable ones?
I imagined it was the same thing, kind of like how they had removable SSD and soldered SSDs but its basically the same thing.

This might be of interest
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

When I started using an eCig (which takes a rechargeable LiCo or LiMn cell), some of the impressions I had were based on my experience with NiMH cells, and I was surprised by how different the two are (and how to treat them, such as how running down a NiMH cell in a deep discharge is often ideal, where as a deep discharge on a lithium cell can equate to more rapid wear [and, with some lithium cells without device protection or integrated production, can damage them should they be discharged past a certain voltage.]) It was also a little frustrating to see that there were ways that Makers could further extend the service life of their device batteries, but, for the most part, don't do this with consumer-level devices.
 
Last edited:
This might be of interest
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

When I started using an eCig (which takes a rechargeable LiCo or LiMn cell), some of the impressions I had were based on my experience with NiMH cells, and I was surprised by how different the two are (and how to treat them, such as how running down a NiMH cell in a deep discharge is often ideal, where as a deep discharge on a lithium cell can equate to more rapid wear [and, with some lithium cells without device protection or integrated production, can damage them should they be discharged past a certain voltage.]) It was also a little frustrating to see that there were ways that Makers could further extend the service life of their device batteries, but, for the most part, don't do this with consumer-level devices.

interesting, so if you have Li-ion battery, the longer you keep your devices on charge the battery?
 
TBH, I wouldn't worry about discharge cycles and all that. just don't let your battery go down too much. Just use your MBP normally. For example, I'm at school today and I forgot my charger at home. Right now I'm at 50%, but by then end of the day ill probably be at 40%. Normally I drain it to 90% in my first class and then I'm able to charge it back to 100% durning my 3 hour break between classes.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.