MacBook Air fails to download large files on battery, but downloads fine on power

SSD-GUY

macrumors 65816
Original poster
Sep 20, 2012
1,057
1,841
Interstellar
Hi all

I'm trying to download Mavericks from the App store on my 2013 MacBook Air 11'.

If I try to download Mavericks whilst on battery, it will get stuck from anywhere in between 25% to 90% done. It says 'calculating' instead of like '5 minutes remaining' or something, and then will eventually say 'Mavericks failed to download, please try again from the Purchases tab'. This is also the case with downloading Yosemite via the Mac App store. Weirdly though, when this happens, I won't be able to access the Internet after that. Everything fails to connect online, including things like Dropbox, Skype etc. However the MacBook remains connected to wifi at all times, and doesn't drop the wifi signal at all.

Now the weird thing is, if I connect the macbook to a power source, it downloads any large fine such as Mavericks or Yosemite fine!

Any ideas what this could be? I'm on 10.9.5 and have all SMC and security updates that the App store allows.

Thanks
 

DeltaMac

macrumors G4
Jul 30, 2003
10,352
2,743
Delaware
I can't give any insight about why that might happen.
But, I will offer my own opinion.
I always connect to power when downloading those large downloads, never on battery only.
And, your experience seems to show that for you, too.
I suppose I have been caught a time or two where the battery went flat during a download, but it's several years ago.
I know that some of the laptops will downclock the CPU on battery. I'm not sure if that also affects your wifi connection, but it appears to in your case.
My theory is that the wifi card heats up during a high-bandwidth download, and you may have a marginal chip that causes you to lose internet (even though your wifi connection to the router appears good, you lose the internet.) You may see this in your Network Diagnostics, where it may show that you are still connected, but no internet.
Download stops, and you likely can reset the connection, the wifi card cools down, and your internet comes back up.

Plug your power adapter in, and you keep everything, because there's enough power to both keep the connection, and continue the download at best speed.

4-year-old laptop - maybe the logic board heatsinks are ready to be redone. Might help - - maybe.
 

SSD-GUY

macrumors 65816
Original poster
Sep 20, 2012
1,057
1,841
Interstellar
I can't give any insight about why that might happen.
But, I will offer my own opinion.
I always connect to power when downloading those large downloads, never on battery only.
And, your experience seems to show that for you, too.
I suppose I have been caught a time or two where the battery went flat during a download, but it's several years ago.
I know that some of the laptops will downclock the CPU on battery. I'm not sure if that also affects your wifi connection, but it appears to in your case.
My theory is that the wifi card heats up during a high-bandwidth download, and you may have a marginal chip that causes you to lose internet (even though your wifi connection to the router appears good, you lose the internet.) You may see this in your Network Diagnostics, where it may show that you are still connected, but no internet.
Download stops, and you likely can reset the connection, the wifi card cools down, and your internet comes back up.

Plug your power adapter in, and you keep everything, because there's enough power to both keep the connection, and continue the download at best speed.

4-year-old laptop - maybe the logic board heatsinks are ready to be redone. Might help - - maybe.
Thanks for your reply. Maybe you're on to something, in terms of the Wifi card and how it mine may need extra power because it's faulty or something.

Anyone else have any ideas in case it's something software wise, or had this problem before? I don't want to go in to the apple store for them to tell me to install a fresh copy/do SMC reset etc, because I've done all this and it still has this problem.
 

Retromac2008

macrumors regular
Oct 9, 2015
187
33
you have different power management settings, so when your pc is disconnected it turns off hd if unused for a while (ex 5min)

try to download the os on battery while using your mac (not afk) and see if it s ok
 

SSD-GUY

macrumors 65816
Original poster
Sep 20, 2012
1,057
1,841
Interstellar
you have different power management settings, so when your pc is disconnected it turns off hd if unused for a while (ex 5min)

try to download the os on battery while using your mac (not afk) and see if it s ok
Even when I'm using the mac it does it.

What power management settings could these be?
 

cruisin

macrumors 6502a
Apr 1, 2014
962
223
Canada
Uncheck "put hard disks to sleep" in Energy Saver like Retromac said.

Maybe make a new user account and try again from there, see if one of your installed apps is conflicting.

Try this: http://howtoapple.com/mavericks-wifi-issues-fix/

If it still doesn't fix itself, then you might have to reinstall OSX or it might be a hardware issue. Before you reinstall, take it to the Apple store so that they can look at the error logs.
 

SSD-GUY

macrumors 65816
Original poster
Sep 20, 2012
1,057
1,841
Interstellar
Uncheck "put hard disks to sleep" in Energy Saver like Retromac said.

Maybe make a new user account and try again from there, see if one of your installed apps is conflicting.

Try this: http://howtoapple.com/mavericks-wifi-issues-fix/

If it still doesn't fix itself, then you might have to reinstall OSX or it might be a hardware issue. Before you reinstall, take it to the Apple store so that they can look at the error logs.
Unchecked the 'hard disk to sleep' in energy saver, and have already tried all of the things mentioned in the link you posted, through searching apple support forums, although it's nice to have it in one place.

Apple told me to reinstall the OS so I have done that, I will be taking it in next week.
 
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