Go Back   MacRumors Forums > Apple Hardware > Notebooks > MacBook Air

Reply
 
Thread Tools Search this Thread Display Modes
Old Nov 15, 2012, 10:03 PM   #1
asenna
macrumors newbie
 
Join Date: Oct 2012
Left MBA fully discharged overnight bad for battery?

I left my MBA fully discharged overnight, is that bad for the battery? I know lithium batteries don't like being discharged.
asenna is offline   0 Reply With Quote
Old Nov 15, 2012, 10:28 PM   #2
filmbuff
macrumors 6502a
 
Join Date: Jan 2011
No, because it wasn't "fully discharged", it was just below the voltage required to run the computer. There is a chip dedicated to keeping your battery from actually discharging or overcharging.
filmbuff is offline   0 Reply With Quote
Old Nov 16, 2012, 01:16 AM   #3
JoeG4
macrumors 68020
 
JoeG4's Avatar
 
Join Date: Jan 2002
Location: Bay Area, Ca.
Send a message via ICQ to JoeG4 Send a message via AIM to JoeG4
Try not to do that again. I killed both my PowerBook G4's battery and my MacBook's battery by running out of juice and then forgetting to charge them for a day or so. When I got around to trying to charge them, the computer wouldn't recognize the battery.

The same dang thing happened to my bro's MacBook battery too!

Basically, there has to be enough power for the battery's control unit to work, and if it manages to get too low (like, you run the computer down to the point that it won't even turn on AT ALL), then after some time there won't even be enough power for the control unit, and unless the control unit has power, it won't let the battery charge.
__________________
I've been a huge fan of Mac OS X since 2001!
JoeG4 is online now   0 Reply With Quote
Old Nov 16, 2012, 10:44 AM   #4
asenna
Thread Starter
macrumors newbie
 
Join Date: Oct 2012
Quote:
Originally Posted by JoeG4 View Post
Try not to do that again. I killed both my PowerBook G4's battery and my MacBook's battery by running out of juice and then forgetting to charge them for a day or so. When I got around to trying to charge them, the computer wouldn't recognize the battery.

The same dang thing happened to my bro's MacBook battery too!

Basically, there has to be enough power for the battery's control unit to work, and if it manages to get too low (like, you run the computer down to the point that it won't even turn on AT ALL), then after some time there won't even be enough power for the control unit, and unless the control unit has power, it won't let the battery charge.
Perhaps the older batteries were more susceptible to this? There was a change in battery technology/performance when they moved up from 300 cycles to 1000 cycles of guaranteed capacity. What year was your brothers macbook?

And cheers to a Bay Area member. Its wet out there today drive safe
asenna is offline   0 Reply With Quote
Old Nov 16, 2012, 05:23 PM   #5
2IS
macrumors 68020
 
Join Date: Jan 2011
Quote:
Originally Posted by filmbuff View Post
No, because it wasn't "fully discharged", it was just below the voltage required to run the computer. There is a chip dedicated to keeping your battery from actually discharging or overcharging.
The man speaks the truth. There's essentially a "cut off switch" with laptops, once the voltage drops below a certain level, it will simply stop providing power to the machine.
2IS is offline   0 Reply With Quote
Old Nov 16, 2012, 05:37 PM   #6
jdavtz
macrumors 6502a
 
Join Date: Aug 2005
Location: Kenya
I doubt it causes harm; Apple actually instruct you to do it for older MacBooks to calibrate the battery/time remaining thing, but say it's not necessary for newer models. They don't say it's harmful.

http://support.apple.com/kb/HT1490
__________________
iMac 27" i7 ('12), MBA 11" ('10), iMac 24" C2D ('08), BlackBook ('07), iMac G5 ('05)
Fuji X100, X-E2, 14, 35, 60
Hablo espaņol
jdavtz is offline   0 Reply With Quote
Old Nov 16, 2012, 05:39 PM   #7
firewood
macrumors 603
 
Join Date: Jul 2003
Location: Silicon Valley
The battery controller doesn't actually let the battery fully discharge. It will shut the MBA down before a dangerously low level. A consumer product Li-Ion battery is designed for several 100 to over a 1000 full discharge/charge cycles before losing half their capacity (and many many more partial cycles), so at most you will lose a fraction of a percent of your battery capacity.
firewood is offline   0 Reply With Quote
Old Nov 17, 2012, 10:58 AM   #8
GGJstudios
macrumors Westmere
 
Join Date: May 2008
Quote:
Originally Posted by asenna View Post
I left my MBA fully discharged overnight, is that bad for the battery? I know lithium batteries don't like being discharged.
I wouldn't do it on a regular basis, but one time isn't going to hurt anything.

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
GGJstudios is offline   0 Reply With Quote

Reply
MacRumors Forums > Apple Hardware > Notebooks > MacBook Air

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Similar Threads
thread Thread Starter Forum Replies Last Post
brand new, fully-charged MBA 11 only shows 3 hours of battery life arrowtree MacBook Air 1 Dec 4, 2013 08:39 PM
Battery went from 45% to DEAD overnight! maverick22 iPhone 6 Feb 19, 2013 01:09 PM
Left new iPhone 5 battery discharged overnight asenna iPhone 3 Dec 2, 2012 12:45 PM
How do I know if my MBA discharged propely? shonor6 MacBook Air 10 Sep 5, 2012 12:00 PM
How can I recover a deeply discharged MacBook battery? kinotix MacBook 3 Aug 16, 2012 04:14 PM

Forum Jump

All times are GMT -5. The time now is 06:30 PM.

Mac Rumors | Mac | iPhone | iPhone Game Reviews | iPhone Apps

Mobile Version | Fixed | Fluid | Fluid HD
Copyright 2002-2013, MacRumors.com, LLC