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

Battery Concern / Question on macbook pro.

S

shmutheprophet

macrumors regular
Original poster
Jun 12, 2008
139
0
Hi everyone.

I just got my macbook pro two days ago and want to make sure the battery will live as long as possible before I need it replaced. Which brings me to my first question: is the battery covered under AppleCare warranty?

Next question: Is it harmful to the battery if I leave my computer plugged into AC power for long periods of time (days)? (I ask this because this would mean the battery is always at 100% which I read was bad for it).

Thanks!

Sam
 
Could be wrong here, but I believe all hardware is covered under Applecare, including battery. Also, I think nowadays it's ok to leave it plugged in. Hasn't affected my performance, at least.
 
i heard that the battery is only under warranty for the first year, with or without applecare.
 
The battery is covered under the standard warranty, but I'm not sure about Apple Care (I don't have Apple Care).

As for your second question...

Yes, leaving the computer plugged in the majority of the time is very harmful for the battery. It will ruin it in fact.

See my post in this thread regarding this :

https://forums.macrumors.com/threads/500099/
 
I wouldn't know about the applecare part of the question, because I don't have applecare. But I can say that leaving your laptop plugged in for hours or even days isn't going to affect your battery life. jcroeth is 100% wrong on this issue. just doing a quick google search will tell you that it isn't going to affect battery life in a noticeable way.

Here is a link I found- http://tech.yahoo.com/blogs/null/67132

But I also know this through personal experience, although that experience comes from a VAIO laptop, and my 7 year old ibook, (which is still on its original battery with 50% capacity left). IF you have problems with your battery, it is most likely a defect in the battery. MBP batteries are notorious for having capacity problems.

Don
 
Icarus73 said:
i heard that the battery is only under warranty for the first year, with or without applecare.
Click to expand...

honeycrisp said:
Could be wrong here, but I believe all hardware is covered under Applecare, including battery. ...
Click to expand...

jcroeth said:
The battery is covered under the standard warranty, ...
Click to expand...


No, batteries are NOT covered under the Apple Limited Warranty and are NOT covered by the AppleCare Protection Plan, except for defects in materials or workmanship.
 
But I can say that leaving your laptop plugged in for hours or even days isn't going to affect your battery life. jcroeth is 100% wrong on this issue. just doing a quick google search will tell you that it isn't going to affect battery life in a noticeable way.
Click to expand...

I did not simply create this theory on my own or something. I, as well, did my online research back when I had a battery issue of my own. As I said in my previous reply, please go read my other post about this issue in another thread. But for convenience, I'll paste that post at the bottom of this one.

Also, I probably should have cited the documents where I got my information in the first place. Sorry. Here are links to the articles with selected relevant quotes.

Apple Publication on Notebook Batteries

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

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. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. 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.
Click to expand...

Article on How to Prolong Lithium-Based Batteries

http://www.batteryuniversity.com/parttwo-34.htm

Although lithium-ion is memory-free in terms of performance deterioration, batteries with fuel gauges exhibit what engineers refer to as "digital memory". Here is the reason: Short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this. If ignored, the fuel gauge will become increasingly less accurate.
Click to expand...

The worst condition is keeping a fully charged battery at elevated temperatures, which is the case with running laptop batteries. If used on main power, the battery inside a laptop will only last for 12-18 months. I must hasten to explain that the pack does not die suddenly but begins with reduced run-times.
Click to expand...


As you see, there are documented reasons not to leave a notebook computer plugged in all the time. The reason I replied to these battery-related threads is that I do not want what happened to me (a ruined battery) to happen to anyone else.

I was going to paste my reply from the other thread here, but in order to keep this post from getting too gigantic, I'll just give a link instead. Please read that post if you're interested in how these batteries work, or if you think my ideas are incorrect.

https://forums.macrumors.com/threads/500099/

So to sum it up... Leaving your notebook plugged in all the time is probably not a good idea.
 
I did read your previous post. As long as you discharge the battery completely once a month, it will make almost no difference whatsoever if you keep it plugged in the rest of the time. Go and search on this forum about MBP batteries, and you will see that MBP batteries have many problems with holding a charge, most of which are manufacturing defects, that apple won't admit exist.

Don
 
Ok let me clarify a couple things here...

First of all, I slightly misread the thread starter's post. They were asking if it was ok to leave the laptop plugged in for days at a time, but I thought they were asking if it was ok to leave the laptop plugged in all the time.

Yes, leaving it plugged in for days at a time is fine, sorry for the confusion. Dmac77 is right, as long as you discharge/charge at least once a month you should be fine.

I did not do that. I had my laptop for 1 year, and it had 17 load cycles on the battery. And many of those were in the first couple months I had it. So it went a couple periods where it was plugged in non-stop for months at a time. That is what I was talking about, and that is very harmful to your battery. (and that is what the documents I linked refer to).

Also, Dmac77, you may be right about defective batteries that lose capacity (even if you treat them properly). But I'm pretty certain that my battery wasn't defective, because its symptoms corresponded very closely with the descriptions of what happens to batteries that are always on AC power.


So basically... Yes, leaving your notebook plugged in for days at a time is fine. But leaving it plugged in all the time and never discharging/charging/calibrating is very bad.

All agree?

Sorry I think we were talking about two different things here. :)
 
Hi guys.

Thanks so much for the replies.

So I should be alright if I will leave my laptop plugged in for 6/7 days of the week or possible a bit longer, then take it out and use it for afew hours then plug it back in? I've just never owned a notebook before and want to make sure I can do whatever I can to help the battery stay good as long as possible.


My brother has an HP laptop with a broken battery and he needs to be plugged in or his computer wont boot up. This is what im scared of.
 
So I should be alright if I will leave my laptop plugged in for 6/7 days of the week or possible a bit longer, then take it out and use it for afew hours then plug it back in?
Click to expand...

Yeah that should be fine. As long as you're discharging/charging the battery at least once a month you shouldn't have a problem.

That article from Battery University I linked in my previous post contains this :

The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible.
Click to expand...

So that's usually what I do. Let it go down to about 30% or 40% or so and then plug it back in.

Now do remember to calibrate the battery at least once a month though. This, of course, involves taking the battery down to 0%

Here is the procedure :

http://support.apple.com/kb/HT1490
 
As others have said only manufacturing defects of the battery are covered. Its sort of up to their discretion, but they say it should stay at 80% health through 300 cycles.

My battery suddenly dropped from 89% health to 65% health about a week ago. When I took it into the Genius Bar they just listened to my explanation of what happened. He walked out to the floor and got a new battery put it in my computer and told me to have a nice day. Didn't even bother looking at my computer to see if what I was saying was true. I thought that was pretty nice - made it faster for me. I was at the bar being helped for like 2 min and now my 1 year 1 month old MBP has a brand new $130 battery in it that I didn't have to pay for. But I think it depends on who you get and how nice they feel like being.
 
Another consideration is not just whether you leave the computer plugged in, but if you leave it on all the time. I did this with my previous notebook, and the battery life decreased significantly over the course of a year, to the point it would only run about 30 minutes (from 3 hours). Leaving the computer plugged in and just turning it on & off for standard daily use shouldn't have a very large impact on the battery. This is, of course, assuming that you do run it off the battery every once in a while. Sleep mode might be different, because there are still components active, generating heat.
 
Okay, so Im a noob (to Mac anyways)

So, from what I understand:

1. A discharge/charge once a month is recommended
2. Discharge/charge does not mean 100% discharge, but partial

Okay, so my question is, how do you know what your battery health is, is it some widget, or in activity monitor? Thanks
 
b. Limitations. The Plan does not cover:

............

(ix) Consumable parts, such as batteries, except in respect of battery coverage under APP for iPod or unless failure has occurred due to a defect in materials and workmanship;
Click to expand...

As to leaving it plugged in all the time - no, that won't shorten it's life.
 
I way I use my computer I have it plugged in the majority of the time, however, once in a while I'm careful to unplug it and let it run down to somewhere around 5-10% before plugging it back in at my desk docking station. I have 54 cycles, 92% health, and 98% power currently and I've had my MBP for roughly 9 1/2 months.
 
Just got my macbook pro (built in batt ) 2 days ago. I had fully charged it and doing a full discharge now.
 
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