[HELP] Mid-2012 Macbook Pro only turns on plugged and instantly shuts down if it's removed.

[LongXP]

For the past 3 or so months I've left my MacbookPro9,2 plugged in and unused as I've gotten better machines to work with. Something came up today though and I need this Mac to work again temporarily, which is when I discover that the battery in this thing doesn't really want to work anymore as it instantly shuts down the device as soon as I pulled out the magsafe cable.


The battery indicator is stuck at 85% w/ the not charging symbol. I've tried a SMC reset which does nothing and also tried removing the battery physically, booting without the battery, then shuts down and replugging it in... which also does nothing. I don't have a spare battery on hand to test if it's really the battery so any guidance would be very much appreciated. Thank you.

 

[smirking]

I would open it up and make sure the battery isn't swollen. I've had batteries go bad and do this exact thing on me. If your trackpad is feeling stiffer than usual when you press, that's a clear sign the battery is expanding.

If the battery is damaged, you can just remove it entirely and use the MBP just fine. It actually might actually work better that way. When mine had a bad battery it would randomly shut down if I left the battery in it.

 

[LongXP]

I would open it up and make sure the battery isn't swollen. I've had batteries go bad and do this exact thing on me. If your trackpad is feeling stiffer than usual when you press, that's a clear sign the battery is expanding.

If the battery is damaged, you can just remove it entirely and use the MBP just fine. It actually might actually work better that way. When mine had a bad battery it would randomly shut down if I left the battery in it.

I've taken it out to inspect it as recommended and there's nothing wrong with it from the outside as far as I can tell. I guess the battery cells inside might be dead though, shame if that's the case.

 

[Scepticalscribe]

I've taken it out to inspect it as recommended and there's nothing wrong with it from the outside as far as I can tell. I guess the battery cells inside might be dead though, shame if that's the case.

Get someone qualified to look at it.

It sounds to me as though the battery is dead, and may need to be replaced, although, as @smirking has already remarked in his excellent post, the machine will work perfectly well without the battery as long as it is connected to an electrical power outlet.

I would open it up and make sure the battery isn't swollen. I've had batteries go bad and do this exact thing on me.

Likewise.

And this means that the battery needs to be replaced.

If your trackpad is feeling stiffer than usual when you press, that's a clear sign the battery is expanding.

Agreed.

If the battery is damaged, you can just remove it entirely and use the MBP just fine. It actually might actually work better that way. When mine had a bad battery it would randomly shut down if I left the battery in it.

Well said.

 

[Grumpus]

If the battery is damaged, you can just remove it entirely and use the MBP just fine. It actually might actually work better that way. When mine had a bad battery it would randomly shut down if I left the battery in it.

I have no direct experience, but it's my understanding that, because the power supply alone may not be able to satisfy peak power demands without the battery present, the laptop's firmware will throttle the cpu to 50%. See this thread, for example, or just do a web search.

 

[KaliYoni]

any guidance would be very much appreciated

If the battery is swollen or damaged, it is an extreme fire hazard. So if you find either is the case with your battery, you should take immediate action.

A DIY repair website I’ve used for a long time, IFixit, has good information for how to handle unsafe Li-ion batteries here:

What to Do With a Swollen iPhone Battery

Learn everything you need to know about replacing your iPhone battery yourself!

www.ifixit.com