Questions tagged [battery]

Concerning devices that store electrical power which can be used to run various devices in the absence of external power.

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111
votes
9answers
172k views

Should I disconnect my MacBook Pro's power cord when the battery is fully charged?

My friend told me that I need to disconnect the power cord when the battery is fully charged. Otherwise, I will shorten the life of the battery. Other people say you should drain it once a month or ...
71
votes
8answers
224k views

Is charging my iPhone all night harmful?

I normally charge my iPhone all night to get 100% power. Does this harm my phone's battery? Update [Oct 1, 2017]: Thanks for all your great answers. I noticed there is a related video which addressed ...
69
votes
9answers
33k views

What are the best practices for battery longevity?

How do you maximize the cycle count of your battery? There seems to be a debate between: Leave plugged in 24/7 but do a full cycle once a month Charge to ~100%, drain to ~10%, repeat. NOTE: Taking ...
68
votes
10answers
149k views

Can I use 45/60/85W MacBook chargers interchangeably?

I have a 13" Macbook Pro that came with a 60W power adapter and a 15" Macbook Pro that came with a 85W power adapter. Can I use either adapter with either laptop? There seems to be disagreement in the ...
58
votes
7answers
42k views

I am missing the option to see the remaining battery life as time in the menubar?

In previous versions of OS X the battery indicator in the menubar included options to show the remaining battery life as percentage or time (or nothing). In Mountain Lion, there's only an option to ...
51
votes
10answers
37k views

Can I manually limit the %CPU used by a process?

I would like to limit the amount of CPU time dedicated to certain processes (e.g. Firefox, Safari, ...). I can't understand why such programs, even when not used (nothing loading, no animations, ...
51
votes
5answers
13k views

Why is it better for an iPhone’s battery to NOT close down apps?

I know apparently it’s not a good idea to close apps on your iPhone to save on battery. I’ve read questions and answers like Does force closing apps have any benefit on iOS devices? but it still doesn’...
42
votes
10answers
54k views

How do I debug an out-of-control “kernel_task” process?

Just recently I noticed my battery life having a pretty significant drop and the "kernel_task" process using quite a bit of CPU (a constant 1-6% on my 2.8ghz dual-core i7, 2010 MBP). Obviously I think ...
34
votes
3answers
91k views

Can I safely charge my iPhone 4 overnight on a regular basis?

First time caller, long time listener: I've seen this question asked on a few other sites but with no "definitive" answers. The Apple website on iPhone batteries is ambiguous, at best, and the ...
31
votes
14answers
29k views

Why is iOS 5 draining my battery so fast?

My wife's phone went from lasting a full day to needing a recharge every few hours after upgrading to iOS 5. Mine still works fine after the upgrade. What might be causing this?
27
votes
4answers
48k views

Difference between autopoweroff and standby in pmset

I just got a new Retina MacBook Pro 15". After getting some downloads interrupted due to the computer going to sleep (even on AC power), I started looking at the man page for the pmset command. I did ...
27
votes
6answers
62k views

How to disable the SpeedStep when using MacBook Pro without a battery?

First of all, the specs: MacBook Pro (15-inch, Early 2011) OS X 10.9.1 (Mavericks) 2.3 GHz Intel Core i7 8 GB RAM The Problem Recently, my battery randomly died and I had to disconnect it, ...
24
votes
8answers
70k views

iPhone 7 won't charge from my MacBook Pro [duplicate]

My iPhone 7 which I recently bought doesn't charge with my MacBook Pro Retina 2015. It always shows for one second that it recharges but then something like lost connection and then again. and goes on ...
23
votes
4answers
22k views

Why does GPS on the iPhone use so much power?

I keep reading in articles that GPS on the iPhone, or any cell phone for that matter, uses a lot of power, but I've never heard an explanation of why. Why is this? The phone doesn't have to transmit ...
23
votes
1answer
24k views

Using bash/terminal to get number of battery recharge cycles

I would like to get the number of recharge cycles using bash (terminal commands). I understand the following command will display all of the battery data, but I want the cycle count on its own ioreg -...
23
votes
4answers
16k views

MacBook Pro 13 with Retina display consumes 10% battery overnight with the lid closed, is this normal?

I bought a MacBook Pro 13 Retina nearly a month ago. Talking to a friend he told me that is not normal for this pc to consume 10% battery over night with the lid closed and with "Power Nap" disabled. ...
23
votes
3answers
31k views

Check the battery level of connected bluetooth headphones from the command line

I am trying to check the battery level of my wireless headphones from the command line. I came across a few discussions, and it seems all I need to do is enter the following: ioreg -c 'deviceName' |...
22
votes
6answers
23k views

How to disable battery charging?

From the pmset man page: POWER SOURCE ARGUMENTS -g with a 'batt' or 'ps' argument will show the state of all attached power sources. […] Certain Apple battery calibration tools may ...
21
votes
3answers
11k views

I think my MacBook Pro battery was replaced by Apple's service team. How do I check that?

I handed my MacBook Pro (15" Touch bar) to the service centre in order to have the keyboard replaced. Now, when I check the battery cycle count, it shows "1". Before it was at "82". Also, I'm ...
19
votes
3answers
21k views

I don't ever use Siri, but it's using too much battery

I never use Siri, but when I look what has been draining my battery it says it's Siri!
18
votes
7answers
362k views

Battery diagnostic tool at Apple Genius Bars

I have a one-year old iPhone 5 and it's battery performance has dramatically decreased over the last few months. As I could use my iPhone for over 24 hours a year ago, the lifespan has halved by now. ...
18
votes
6answers
53k views

How do I check an iOS device's battery health?

I am looking for a way to check the current health of a battery for iOS devices, similar to how coconutBattery works for OS X. How can I check the battery health for an iOS device?
17
votes
14answers
91k views

How long should my MacBook Pro battery last?

I have brand new Macbook Pro (15", i5 2.4GHz, 4Gb RAM) purchased at the end of May 2010 and Apple advertises up to 7 hours of wireless web battery life, however I consistently getting only about 4 ...
17
votes
4answers
6k views

Can iPhone battery apps actually prolong battery life?

I've seen a few apps that claim they do some kind of conditioning/deep charge/other jargon to extend the life of an iPhone battery. Is this just hokum or do I really need one of these apps to maximize ...
17
votes
5answers
7k views

Is a refurbished Macbook Pro's battery new?

When you buy a refurbished Macbook direct from Apple, is the battery in it new? I cannot seem to find a definitive answer on their website or on the internet. I am concerned that the savings from ...
17
votes
3answers
7k views

Get low battery notifications for mouse earlier

Is it possible to tweak the % that I get warning of low battery for my Magic Mouse 2? I currently only get it at 2% at which point it's very close to dying so I have to stop what I'm doing and plug ...
16
votes
5answers
19k views

Is the Macbook 12 inch's USB-C charger interchangeable with other USB-C chargers or devices?

If there is only the Macbook 12 inch USB-C charger nearby, can it be used to charge other USB-C devices, such as any Android phones that also use USB-C? (will it "too powerful" and damage other ...
16
votes
3answers
22k views

Why does my MacBook Pro die without warning?

I have a MacBook Pro (about 18mts old) which has recently started to inexplicably die without warning. I'm running it on battery and, yes, it's getting close to the bottom end (between 10 and 25%). In ...
16
votes
4answers
13k views

Why won't my MacBook Pro automatically sleep?

I have my MacBook set to go to sleep after 2 minutes while on battery (via the Energy Saver preference pane.) However, when I leave it idle, it only turns off the screen—it does not actually sleep. ...
15
votes
2answers
26k views

How to know the duration of battery usage in one session?

I would like to know how long was my battery running since it's last charge. There is a built-in time-remaining counter but I would like a time-used counter.
15
votes
4answers
20k views

Charging an iPhone, difference between USB port and power outlet

The power outlet has more power obviously, but maybe the computer USB is suffice to charge it at maximum speed. Is there a difference between charging an iPhone using the computer USB port and using ...
15
votes
4answers
66k views

How to maximize Macbook pro retina's battery life when working with AC power? [duplicate]

I'm working 95% of my time with AC power and Thunderbolt Display. Since macbook pro retina's battery are no longer easily switchable I'm concerned about it's life and would like to maximize it. Before ...
15
votes
7answers
25k views

Macbook Air - battery drains while sleeping (but not when shut down)

My macbook air (13-inch, mid 2011) battery drains from ~100% to ~85% over night. The problem only started a few months ago. I'm currently running yosemite, but the problem started while on mavericks....
14
votes
2answers
1k views

How can I verify if Apple is slowing down my phone because of an old battery?

Apple has recently confirmed they're slowing down phones which have a battery that's too old. How can I verify if that's the case for my particular model? Is there an app that can tell me the current "...
14
votes
4answers
3k views

2016 Touch Bar MBP drains battery in sleep

A full battery will drain in about 24 hours of lid closed, fully unplugged sleep. Sometimes, when I pick up the computer to use it, it's physically warm. Here's what I've tried: Power Nap on battery ...
14
votes
1answer
706 views

Is there an App for determining the current capacity of an Apple watch battery?

I see from Mactracker that a new battery has a capacity of 205 mAh (38mm Apple Watch Series 1). For the MBP and iPhones I have used coconutBattery to show the decay in battery capacity over the ...
13
votes
1answer
632k views

iPad won't turn on after a complete battery drain

My iPad mini retina is out of warranty, I forgot to plug in my iPad after the critical battery warning and it went some minutes following the warning. I was not worried because same thing had ...
13
votes
3answers
5k views

Is it safe to always leave a Macbook Pro on?

I have an external monitor, keyboard, and mouse connected to my Macbook Pro. I have the lid closed and have it running. I run it as if it were a desktop PC, always on. I only shut off the LCD ...
13
votes
1answer
5k views

Before putting an iPhone5 into very long-term storage should I fully drain battery?

I just migrated an iPhone5 to an X. I'd like to put the iPhone5 into very long-term (probably 1+ year) storage. While I'll hopefully never need it again, I'd like to keep a back-up iPhone at the ready....
13
votes
5answers
65k views

iPhone 5S suddenly turns off at 30-40% of battery life

I have iPhone 5S with 10.1.1 iOS. I have experienced few situations where my battery life was about 30-40% and iPhone immediately turned off. When I tried to turn on it indicated low battery and kept ...
13
votes
1answer
8k views

Should I avoid booting my MacBook if it's really cold?

As the title says; if my MacBook has been exposed to minus degrees, should I wait for it to reach room temperature before I boot it or am I just paranoid and have nothing to worry about?
13
votes
3answers
16k views

Force “low power mode” on mac

When there is less than 5% battery left on a mac, the battery indicator goes red and system performance significantly drops - presumably in an attempt to make that remaining 5% last a little longer. ...
12
votes
2answers
97k views

Does the Apple Genius Bar replace Macbook Air battery on site?

I called Apple's toll free number but wasn't able to get a clear answer from them. My 2011 MacBook Air's battery is dying and I would like to have it replaced. The only problem is that I am ...
12
votes
3answers
304 views

What is the procedure for replacing the battery on an iPhone?

What is the procedure for replacing the battery on an iPhone?
12
votes
5answers
244k views

Why do iOS devices take such a long time to turn back on?

Often I will realise my iPhone or iPad is about to run out of battery, run around the house looking for a charging cable and plug, and get back just in time to see the screen go black and the little ...
12
votes
2answers
6k views

Should I use the adapter or the battery?

I want to know when my MBP's battery was fully charged it's better to unplug my adapter and use my battery power or still let use adapter power? I somewhere read that when MBP's battery was fully ...
12
votes
2answers
66k views

What causes iPhone low battery crashes? Is there a software fix?

Some iPhone users (especially those with devices that've been in use for a while) encounter a problem where the device crashes once the battery gets low. For example: "After updating to iOS 7 my ...
12
votes
1answer
3k views

Is there a solar panel to charge a MacBook Pro 2016?

I want to buy a MacBook Pro 2016, probably the 15" model. Since I travel around on my bicycle a lot, I'd find it really nice if I could charge it with a solar panel. Does anyone know how much Output ...
11
votes
5answers
34k views

Does overcharging a MacBook degrade its life?

I have an early 2011 13" MacBook Pro and I use it almost like a desktop. I leave the power cord connected all the time. Is this OK? Am I ruining the computer or diminishing its lifespan?
11
votes
2answers
836 views

Battery warning ''Service battery"

Battery warning "Service battery". This warning have appeared in my MacBook Pro (2008) with Snow Leopard. Is there a way to find out what a reason of this warning, without apply to service centre?