The electricity drained by a device

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31
votes
9answers
43k views

Can a 60W MagSafe power adapter work interchangeably on a Macbook Pro that “requires” an 85W adapter?

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 ...
21
votes
8answers
30k views

Is it OK to charge my iPhone with my iPad charger?

I have an iPhone 4 and an iPad. Since the iPad really charges best off the wall charger I keep it plugged in, but I usually just charge the iPhone off the computer. Although frequently if the iPad ...
16
votes
6answers
9k views

iPad displays “Not Charging” when plugged into USB ports. What can I do?

When I plug my iPad into my computer's USB ports, the iPad battery area displays "Not Charging". I understand the iPad requires more wattage to charge compared to an iPhone or iPod, as evidenced by ...
14
votes
3answers
10k 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 ...
14
votes
4answers
8k views

What's the point of the 60W Apple MagSafe replacement charger?

One of the cable tabs on my MagSafe charger for my MacBook came undone, so I took this as a sign to retire the charger to home use and to purchase another for travel. When I went to my local Best Buy, ...
12
votes
3answers
2k views

Can I restore pre-Mavericks power key behavior?

Mavericks changed the behavior of my MacBook Air's power key to put the Air to sleep immediately when pressed briefly. Prior to Mavericks, the power key would summon the Shut Down dialog. As ...
12
votes
5answers
13k views

What would happen if I use a Macbook Air Powersupply with a 15" MacBook Pro Retina (or vice versa)

My girlfriend has a Macbook Air. The power supply is smaller and lighter than the Pro. It has an output of 14.85V and 3.05Amps. My Pro Retina has a power supply that is 20V and 4.25 Amps. Both ...
10
votes
8answers
7k views

How to retrieve current wattage info on OS X?

Is there a way to retrieve the current watt usage info on OS X Snow Leopard? I'm using mid-2010 iMac, so I'm not looking for just battery-related apps. Does OS X even monitor power usage? Do I need ...
10
votes
2answers
3k 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 ...
10
votes
2answers
473 views

How does Apple calculate the energy consumption of a process in OS X Mavericks

In OS X Mavericks you can monitor the energy consumption of different processes in the "Activity Monitor"-App. Also there will be a menu bar icon which lists the most energy consuming applications ...
10
votes
1answer
210 views

Macbook started to consume battery more quickly

This seemed to happen after I did several things at once (all of which I have since reversed in trying to track this down): installed a (Crucial M4) SSD drive (replacing my old SATA 5400 RPM drive), ...
9
votes
2answers
775 views

Why can my Mac charge my iPad but other computers can't?

What do Macs do differently so its USB ports can charge my iPad, but if I plug into a USB port on my PC I get the "not charging" message?
9
votes
2answers
7k views

How to monitor USB power consumption?

I'm looking for a way to monitor the power being drawn from the USB ports on my Mac. System Profiler doesn't appear to display this and I haven't been able to find any applications or tools to do the ...
8
votes
4answers
5k views

Does an iPad consume more battery power when there are multiple applications open?

Does an iPad consume more battery power when there are multiple applications open compared to let's say, having only one application resident in memory? If there are differences between the ...
8
votes
2answers
6k views

How can I keep my Mac awake AND locked?

I want to leave my Mac awake overnight so it syncs 4GB of data from Dropbox. I need to prevent the machine from going to sleep because that pauses the Dropbox sync I've been using Caffeine to keep ...
8
votes
1answer
1k views

Phone-only mode on iPhone

Is there a way to switch the iPhone’s functionality to a phone-only mode. In this mode only incoming (and possibly outgoing) calls and SMS messaging would be activated. All other services (location, ...
8
votes
3answers
9k views

What is the iPhone's standby policy regarding WiFi and 3G?

I have an iPhone 4s with the latest iOS. It seems that when I wake it up from standby, it switches from 3G (or EDGE) to WiFi. Judging from that, I suspect it turns off WiFi when in standby, and only ...
8
votes
6answers
29k views

“USB device drawing too much power” error on startup with no devices connected

Since upgrading to Lion, I get this error every time I start up: I've read the answers suggested here, but they seem to indicate that it's the presence of a second device that's causing the ...
7
votes
7answers
10k views

How can I avoid my MacBook Pro giving me minor shocks?

The aluminum Macbook Pro gives a mild shock when connected to a wall socket and charging. It only happens when I'm, for example, not wearing shoes or slippers and my feet are resting on the ground ...
7
votes
3answers
14k views

Can i use my old MacBook charger on my new Mac?

I have a 2011 15" MBP, that uses a 85W power supply. My old 2008 MBP 15" also has a 85W power supply, but I cannot get it to work. Shouldnt it? Its the same watt power, and the adapter fits.
6
votes
3answers
14k views

Does closing the lid put a MacBook Pro to sleep? Would it hurt the computer if I carry it around without shutting it down?

When I first got my MacBook Pro, it took less than 30 seconds to start up. Now, after several months, it takes about two minutes to startup and I can tell that it is not as responsive when using some ...
6
votes
3answers
2k views

Using my iMac in a country with a different power supply standard

We may be relocating to a different area of the world where the power standards and outlets differ considerably from what I've got here in North America. Is the power supply in my iMac ...
6
votes
3answers
8k views

How do I locate applications that drain my battery on a MacBook Pro?

I purchased a new Macbook Pro and have since downloaded a ton of applications and add ins. I think some of these apps are responsible for draining my battery too quickly. How do I identify what ...
6
votes
2answers
524 views

Xserve shuts itself off and boots at will

Okay, there's a lot of smart Mac guys here, so lets see if any of you can figure out this stumper. Our Xserve G4 (RackMac1,1) went incommunicado a few years ago was left in this state until I pulled ...
6
votes
1answer
3k views

Does powertop work with Mac OS X Snow Leopard or are there other power profiling utilities?

I recently came across a blog post highlighting powertop for Linux (see: http://www.lesswatts.org/projects/powertop/). Based on the FAQ, powertop relies on the fact that the Linux kernel is now ...
6
votes
1answer
268 views

Mac display won't turn on

I have an Apple HD display that has been in our IT depart for a few months now. It was working fine until recently (the past month or two). I can turn it on and it will work for a few days, but then ...
5
votes
2answers
5k views

Monitoring power consumption on Mac

The Android OS monitors the power consumption of running apps and hardware (display). As you may guess, this is a useful feature as it allows to track down energy greedy apps. Is there an application ...
5
votes
3answers
1k views

Is it bad when my iMac is constantly on?

Is it bad if I never shutdown my computer? I am asking solely terms of hardware so let's assume my software is stable and I reboot regularly to clean up software errors. If running constantly is ...
5
votes
2answers
10k views

How do you check how much current a Mac USB port can deliver?

This question is similar to the superuser question "How to check how much power a USB port can deliver", which is answered for Linux and Windows. How do you check the same on a Mac?
5
votes
1answer
1k views

Is there a way to get the OSX battery icon to display both percentage and time?

I am working on a 2006 MacBook with Snow Leopard. The battery level indicator has the option to show Time or Percentage remaining. I would like to show both. Is there a way to enable this? or Can ...
5
votes
1answer
980 views

Are the mid-2012 Macbook Air compatible with older MagSafe adapters?

Will the mid-2012 Macbook Air models be compatible with the MagSafe power supply of the previous generations?
5
votes
1answer
11k views

MacBook Pro Charger has stopped working properly - any short-term fixes?

I have a MacBook Pro 15", about a year old. Today, the charger started working only intermittently. I've seen a few other people talking about similar problems, and most people say it's a problem with ...
5
votes
3answers
7k views

Which uses more battery when tethering - Wifi or BT on iPhone 4S?

I'm not really bothered which is quicker - I'm guessing this is wifi anyway. I just want to know which would allow me to get the most life out of my iPhone 4S when tethering to it with may MBP. ...
5
votes
1answer
383 views

At what point do iPads stop displaying “not charging” when connected to power?

I am curious if anyone has measured directly or found an authoritative reference that documents at which point the various iPad will display charging and not "not charging" in the menu bar while ...
5
votes
1answer
1k views

iPod classic 80GB won't charge from usb power adapter

iPod classic 80GB 2007 [Model No.:A1238] won't charge from LG usb travel adapter (output 5.0V, 0.85A). It normally charged from Apple 5W USB Power Adapter [Model No.:A1299] (output 5.0V, 1A), and ...
5
votes
1answer
4k views

Easy way to disable processor cores on the fly

Hey i'm looking for a fast way to disable processor cores of my macbook to save power when i'm stranded away from a charger. I'm away that instruments can do this from it's preferences, but that's a ...
4
votes
2answers
5k views

For least power usage, should I turn off or put my Mac to sleep?

If I'm not going to be using my Mac for a while, am I better off shutting it down completely or just putting it to sleep? Obviously it uses more power to "sleep" than to be off completely, but it ...
4
votes
1answer
83 views

Energy saver: do the battery settings apply during charging?

I have my Macbook pro 17 (early 2011, OSX 10.6.8) set to turn off the display at 30 minutes on AC, and 10 minutes on battery. I've noticed recently that if the battery is charging (the little battery ...
4
votes
1answer
299 views

Can you power on a MacBook with a wireless keyboard?

Is it possible to power on a MacBook using a wireless keyboard? If that sounds strange, I'm asking because I use a Bose radio as the sound system and the radio fits nicely on top of the laptop.
4
votes
2answers
151 views

Unexplainable large number of cycles of MacBook Battery

My battery is a year old, but it has 189 cycles. Why is this? I always use my MacBook with the charger plugged in and very rarely without the charger.
4
votes
3answers
2k views

“usb device was drawing too much power” error message

Ever since I upgraded to Lion, I've been getting this error message a lot. It seems to trigger(not every time though) when I plug in my iPhone to the usb port on my keyboard. The only other USB ...
4
votes
1answer
611 views

Should I spin down Mac Mini's drive?

I have a Mac Mini (2010) that I use as a home server with a DAS (2 drives) attached over USB. Everything is on 24/7. From all my research online, it seems that spinning hard drives up and down ...
4
votes
5answers
589 views

No Batteries Available ?-How to Check battery health on MacBook Pro early 2011

A few days ago, I went on vacation and unplugged power cable from my MacBook Pro 13' early 2011 and then I got back home, the battery was not detected by OS and didn't charge. I then understood that I ...
3
votes
2answers
6k views

Is there a presentation mode on mac?

When watching a video, or making a presentation, is there an option or a tool to disable all screensaving, energy savings and all? Regardless of if the power is plugged, I'd like to keep the screen ...
3
votes
1answer
233 views

What is the data corruption risk of force shutting down a running Mac?

Eg when the power supply is cut or someone presses the power button for 5 seconds? How big of a risk am I taking to my data? Is it a 1% chance of corrupting data? I know most mac these days have a ...
3
votes
1answer
294 views

85W MagSafe adapter only delivers 77W?

My late 2011 17" MBP was delivered with an 85W MagSafe adapter. Under heavy stress (either CPU and/or GPU) the MBP has to draw additional power from the battery in order to keep everything running. ...
3
votes
1answer
21k views

Is it safe to use my US iPhone/iPad charger with a simple European plug adapter?

I'm using the US wall adapter that came with my iPhone to charge it: When I travel to Europe, is it safe to use this with a simple US-European adapter, or do I need a transformer or some other ...
3
votes
4answers
1k views

MacBook won't sleep while charging

An ongoing problem: my MacBook Pro (i5, 2.4ghz, 15") won't sleep while charging. I close the lid, but I don't get the pulsing "sleep light", it just stays fully illuminated. If I listen closely, I ...
3
votes
3answers
4k views

Lion - Macbook randomly wakes up from sleep when lid is closed

I have aluminium macbook (not pro). I have recently updated to Lion. So far so good - had some minor issues with printer, sshfs, mac fuse. Managed to resolve almost all of them. There is one issue ...
3
votes
1answer
4k views

Why does battery die during sleep mode?

I'm running MacOSX 10.5.8 on a MacBook Pro. I was working on my computer last night. I finished work, closed the lid and expected the computer to go to sleep. I assume this is the Apple Safe Sleep ...