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

Battery Suddenly Unhealthy?

M

Melodeath

macrumors 6502a
Original poster
Dec 9, 2009
580
48
Hey, I've had a Macbook Pro for two years (it's a mid-2010 i7, 15"). I last "calibrated" the battery in January, and at that time, the listed battery health went down from 97% to 85%. That got me a little worried, but I didn't think too much about it.

I generally leave the MBP plugged in all the time, and from what I understand, modern Macbook Pros are designed to handle this fine.

Then yesterday I was watching a video while using battery power, and after about 45 mins, I got a warning saying the MBP was on reserve power. I've never experienced that message before after such a short period of time. I then check my battery health and it's at 45%. When I click the battery indicator at the top of the screen is says "Service Battery," which I've also never seen.

I do have Apple Care for another year, but the nearest Apple store is a 2-hour drive away.

Does anyone have any idea how the health of the battery could drop from 85% to 45% so suddenly?

And do I have to go to an Apple Store to fix this under Apple Care, or can I go to any place that is certified to repair Apple computers?

Thanks for any help you can offer

Edit: The battery has 107 cycles on it
 
Melodeath said:
Hey, I've had a Macbook Pro for two years (it's a mid-2010 i7, 15"). I last "calibrated" the battery in January, and at that time, the listed battery health went down from 97% to 85%.
Click to expand...
The built-in batteries in the newer Mac unibody notebooks come pre-calibrated and do not require regular calibration like the removable batteries. Also from the Battery FAQ:
Calibration does not affect your battery health, improve battery performance, or extend battery life. It does make battery condition reporting more accurate, so when your battery reports 97% health, it's more accurate. Without calibration, your battery health could be 60% but still being reported as 95%, for example.
Click to expand...

Melodeath said:
I generally leave the MBP plugged in all the time, and from what I understand, modern Macbook Pros are designed to handle this fine.
Click to expand...
That's not true. Also from the FAQ: Apple does not recommend leaving your portable plugged in all the time.

This should answer most, if not all, of your battery questions:
 
GGJstudios said:
Not necessarily, since the OP said they leave it plugged in all the time. Doing so can bring a battery to an early death.
Click to expand...

Apple only recommend that you don't leave it plugged in constantly, they don't make any particularly strong warning about it or explain what it could do. I do not at all believe it would cause such a huge depletion of the battery's capacity, especially when it's said to reach about 80% after 1000 cycles.
 
Dangerous Theory said:
Apple only recommend that you don't leave it plugged in constantly, they don't make any particularly strong warning about it or explain what it could do. I do not at all believe it would cause such a huge depletion of the battery's capacity, especially when it's said to reach about 80% after 1000 cycles.
Click to expand...
There have been countless reports of batteries dying quicker by leaving them plugged in all the time.
For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time.
Click to expand...
 
GGJstudios said:
There have been countless reports of batteries dying quicker by leaving them plugged in all the time.
Click to expand...

Yes, but if leaving it plugged in constantly would kill the battery in that way within a year, they would probably be "a bit" more explicit with that being a huge no-no.

Unless there have been reports where people haven't been able to get new batteries despite the 80 %/1000 cycles within the warranty period with the argument that they've left the charger in too much, my guess is that your charger-habits won't affect the warranty of the battery.

Although I you're right in saying that the number of cycles isn't really the only thing to look for, but time is also something that plays a huge role in determining how plausible it is that the battery is defect.
 
"If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month."

So it can't be all that essential that the battery be constantly used...
 
I don't think Apple would refuse replacing a battery under Apple Care just because I have the MBP plugged in a lot of the time. I use battery too, but when I'm working at my desk, I leave it plugged in so I don't have to worry about unplugging and replugging, and making sure it drains every so often. That just doesn't make sense to me.

And yes, I would definitely say theres a defect if I'm at roughly half capacity after 100 cycles and 2 years of owning it. Isn't that roughly one cycle every 7 days? Doesn't seem that crazy to me.

So can I get the battery checked out an any Apple-certified shop, or strictly an Apple store?

Thanks
 
FWIW I adopt Apple"s battery advice. My MBP still charges to 101 % after over six months of use. My MBA achieves 97% I alternate between using them on battery power and on main power. Works for me. None of my three iPads ever had issues either, although that's a different ball game. My new iPad has been used all day yesterday andnim on it now. It is streaming radio to my AEBS and I'm browsing the web, still looking for a decent case without magnets, and the battery is showing 57%

I tend to use my iPad at night, so when it hits the 10% mark, I will put it on charge,mand by then it will be coffee time, and a switch to my MBA. The Air probably gets more use than my pro at home simply because a 17" lump on my lap, as nice as the screen is, just isn't all that practical.

Moral is, follow the FAQ and your battery should last the distance.
 
Both my batteries do this. I'm (un)lucky enough to not have the unibody MB. Currently it's sitting at 1100 cycles and 90% health, but will drop down to 30-40% health every now and then. I think my other battery is at like 5% health so I kinda gave up on that one.

I have not done any of the calibrating in awhile either. I've pretty much come to rely on having access to the charger.
 
StuLax18 said:
Both my batteries do this. I'm (un)lucky enough to not have the unibody MB. Currently it's sitting at 1100 cycles and 90% health, but will drop down to 30-40% health every now and then. I think my other battery is at like 5% health so I kinda gave up on that one.
Click to expand...
Your battery is designed to retain up to 80% of its capacity up to 300 cycles. Since you're almost 4 times that, I'd say you've gotten your money's worth out of it. Batteries don't last forever. It's time to buy new ones.

StuLax18 said:
I have not done any of the calibrating in awhile either. I've pretty much come to rely on having access to the charger.
Click to expand...
That's why your readings are so inaccurate. You should calibrate to get a true picture of your battery condition.
 
Melodeath said:
I don't think Apple would refuse replacing a battery under Apple Care just because I have the MBP plugged in a lot of the time. I use battery too, but when I'm working at my desk, I leave it plugged in so I don't have to worry about unplugging and replugging, and making sure it drains every so often. That just doesn't make sense to me.

And yes, I would definitely say theres a defect if I'm at roughly half capacity after 100 cycles and 2 years of owning it. Isn't that roughly one cycle every 7 days? Doesn't seem that crazy to me.

So can I get the battery checked out an any Apple-certified shop, or strictly an Apple store?

Thanks
Click to expand...

If they ask if you keep it plugged in a lot, I'd tell them otherwise to make things easier for you.
 
Dangerous Theory said:
If they ask if you keep it plugged in a lot, I'd tell them otherwise to make things easier for you.
Click to expand...

If I was the genius, this would be me:

17841849.jpg
 
Call me crazy, but honestly, I would consider it pretty ridiculous if they refused to replace such an obviously defective battery that is under Apple Care, especially considering the computer does not ship with a giant warning printed to not leave it plugged in while you work. I would understand if there was no Apple Care, but yeah, there is in this case. Of course, I would be a lot more open to the idea of letting the battery drain from time to time if doing so didn't erase my System Clock and Wi-Fi passwords every time, or corrupt some piracy-protection software I need to run software for work.

Regardless, I'm getting a diagnostic test at an Apple-certified store to determine if the battery is defective.
 
It could be a mis-read of the battery or an actual issue with the battery. The only way to know is to check with Apple.

I'm at 700 cycles on my Mid-2010 MacBook Pro that I bought 14 months ago and my battery life dropped to 79% then went up to 94% then now settled at 88% and jumping around from 85-90%.
 
I leave mine plugged it all the time when I'm not taking it or using it in class. Although I try to discharge it completely at least 2-3 times a month. I have had mine for about 7 1/2 months and have cycled it 68 times. I have kept track of my full capacity (8500~mAh) and it still holds around 8450~ mAh on a full charge.
 
Melodeath said:
Call me crazy, but honestly, I would consider it pretty ridiculous if they refused to replace such an obviously defective battery that is under Apple Care, especially considering the computer does not ship with a giant warning printed to not leave it plugged in while you work. I would understand if there was no Apple Care, but yeah, there is in this case. Of course, I would be a lot more open to the idea of letting the battery drain from time to time if doing so didn't erase my System Clock and Wi-Fi passwords every time, or corrupt some piracy-protection software I need to run software for work.

Regardless, I'm getting a diagnostic test at an Apple-certified store to determine if the battery is defective.
Click to expand...

Letting the battery drain doesn't mean fully - just down to a few % is fine. As long as you go in there kindly and not with an entitled attitude they should be willing to replace.
 
Dangerous Theory said:
Letting the battery drain doesn't mean fully - just down to a few % is fine. As long as you go in there kindly and not with an entitled attitude they should be willing to replace.
Click to expand...

Sure, I was actually referring to the whole "calibrate" process. My point was simply that I don't even like to risk the idea of running out of battery.

I'm a polite dude haha. I don't cause scenes. I have no sense of entitlement other than believing that if part of the computer is deemed defective, and I have apple care, it should be replaced. Of course, anyone is entitled to what they paid for with an extended warranty.

Btw, the store ran the battery diagnostic and the battery indeed came back as defective. They have to submit the report to Apple, who then reviews it and decides if they will mail a new battery. They mentioned something like batteries only being covered for a year, even under Apple Care, which I haven't heard before. In which case I would have to buy the battery, but "labor" of installation would be covered by Apple Care. I'm guessing Apple will send a new battery, but we'll find out soon!
 
Melodeath said:
They mentioned something like batteries only being covered for a year, even under Apple Care, which I haven't heard before.
Click to expand...
That's not true. Read the BATTERIES ARE NOT COVERED section of the Battery FAQ. If the battery is defective, it's absolutely covered by both the warranty and AppleCare.
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back