Travel Technology - Why doesn't the MagSafe Airline Adapter work with my MacBook Pro?

Why doesn't the Apple MagSafe Airline Power Adapter work with my MacBook Pro 2.66GHz 15" using AA seat power?? Have other people been successful sustaining the battery of a 2008/2009 MacBook Pro 15"? My adapter cable glows green when plugged in, but could it be faulty in some other way?

With my previous model MacBook, the AA seat power sometimes sustained my battery, sometimes not. But with my current (early 2009) MacBook Pro, AA seat power has never sustained my battery (except once for a few minutes).

AA seat power is rated 15V, 75W (ie 5 amps). I have monitored the battery consumption (using XBattery (http://www.kezer.net/shareware/xbattery/)) when plugged in to the seat power, and it is usually about 1.5A amps (which makes sense, as this would give about 3 hours battery life with my 4.6Ah battery).

Clearly the MacBook power consumption would be higher (and could exceed 75W) if the battery was charging.

So what can be happening? The MagSafe adapter is designed to limit the current. So why is it not supplying any power to my MacBook?

Why doesn't the Apple MagSafe Airline Power Adapter work with my MacBook Pro 2.66GHz 15" using AA seat power?? Have other people been successful sustaining the battery of a 2008/2009 MacBook Pro 15"? My adapter cable glows green when plugged in, but could it be faulty in some other way?

the short answer is seems to depend on the plane.

i've been using a magsafe airline adapter with a 15" macbook pro for over a year and up until a month ago, i had no problems whatsoever. the battery did not discharge at all. the adapter worked great, other than not recharging the battery, which is a stupid misfeature.

however, in the last month or so, i've been on several flights where the battery discharged. in one case, the battery was discharging in the early part of the flight, but after the meal (and on the same plane), the battery level did not discharge, even when stress testing it by playing a movie at full brightness. on a pair of fights last week, the battery discharged on the first flight but maintained its charge on the second flight.

Why doesn't the Apple MagSafe Airline Power Adapter work with my MacBook Pro 2.66GHz 15" using AA seat power?? Have other people been successful sustaining the battery of a 2008/2009 MacBook Pro 15"?
From http://store.apple.com/us/product/MB441Z/A:
"Using the MagSafe Airline Adapter provides power for your computer but does not charge the battery."

I have monitored the battery consumption (using XBattery (http://www.kezer.net/shareware/xbattery/)) when plugged in to the seat power, and it is usually about 1.5A amps (which makes sense, as this would give about 3 hours battery life with my 4.6Ah battery).
That would be the current required for the operation of the MacBook itself (which the adapter should be able to provide). That figure would not show the total current you are trying to draw from the adapter (operation + charging).

The MagSafe adapter is designed to limit the current. So why is it not supplying any power to my MacBook?
The way it, most likely, "limits" the current is by shutting itself down if the limit is exceeded.

You need 85W to charge and use a new MBP at the same time. Most planes (UA, AA, etc.) the circuit will trip and the power port will shutdown if anything tries to pull more > 75W.

Might be worth checking this out:

http://mikegyver.com/IdeasnProducts/Macbook-Car-Charger-Adapter/

I don't have any first-hand experience with it.

You need 85W to charge and use a new MBP at the same time. Most planes (UA, AA, etc.) the circuit will trip and the power port will shutdown if anything tries to pull more > 75W.

although the macbook pro adapter is 85w, a macbook pro will work fine (and charge, but slower) using the macbook 60w adapter. there's a chip in the power adapter that tells the laptop how much power the adapter can supply and if charging should be disabled, as with the airline adapter.

85w is also the maximum it can use; if the battery is fully charged, there's no need to draw any extra power to charge it so the adapter will probably consume under 75w.

although the macbook pro adapter is 85w, a macbook pro will work fine (and charge, but slower) using the macbook 60w adapter. there's a chip in the power adapter that tells the laptop how much power the adapter can supply and if charging should be disabled, as with the airline adapter.

85w is also the maximum it can use; if the battery is fully charged, there's no need to draw any extra power to charge it so the adapter will probably consume under 75w.

As I noted, the normal current consumption without charging is around 1.5 A, ie less than 20W.

The MagSafe adapter limits the current, hence the power port does not shut down. So it is a bit of a mystery why the power port often does not supply the needed 20W to prevent battery discharge. :confused:

Is this just a problem with AA power ports?

I'm on a DL flight in First/Business. When I plug in my MBP adaptor, the computer ACTS funny, the mouse is spotchy, and I have the feeling that power is not consistent or something. I hope it doesn't do anything bad to the computer.

I'm on a DL flight in First/Business. When I plug in my MBP adaptor, the computer ACTS funny, the mouse is spotchy, and I have the feeling that power is not consistent or something. I hope it doesn't do anything bad to the computer.
There is no obvious reason for this, if your battery has adequate charge. Maybe the adapter is faulty?

On a related thread in the Aadvantage forum, one person whose MacBook Pro did not charge, found it was OK with a replacement cable. The overall conclusion was the possibility of more faulty cables:
The score so far for MacBook Pros:

Always works: CRCJ, lalar3
1st faulty, 2nd always works: Alka
Always works but sometimes drains the battery: TheDudeAbides
Sometimes worked(?): pjoalfa
Rarely works: nbevan, GeneCMH

Although I don't see a pattern, since two people with the same model as me are getting good results, I am hoping that my problem (and perhaps GeneCMH's?) may be a faulty cable.

it is just odd. everything was fine this AM at home, and when I unplug the adaptor, all is normal. Odd. I think the power output is off.

Odd, I have a late 2006 MBP. Airline adapter always worked for me on AA S80, 737 and 767. A flight a few days ago it seemed to be holding the battery. I put the MBP in the seat pocket for the meal (left the adapter plugged in to the Mac). When I started to use it again the battery was draining.

Next 3 flights, the adapter hasn't held the battery at all. Sounds like a faulty adapter. I'll see if the Apple Store will switch it out as it is within the warranty period.

Seems odd though as it is a such a simple adapter. Maybe more electronics in there than we know about?

although the macbook pro adapter is 85w, a macbook pro will work fine (and charge, but slower) using the macbook 60w adapter. there's a chip in the power adapter that tells the laptop how much power the adapter can supply and if charging should be disabled, as with the airline adapter.

pdxer is right. I had previously learned this from a friend in hardware engineering at Apple. (I used to work there.) I recently picked up a 60W adapter in London. It solves two problems for me: 60W power on NH and VA flights and a UK plug cable for use when the UK "duck head" doesn't fit, such as the recessed plugs in the boardroom table in our London office.

I wanted to report back that having Apple replace my 6 month old airline adapter fixed my issue. The bottom line is that an airline adapter can appear to be working (green light on) and the computer says it is receiving power, but that doesn't mean your airline adapter is actually working. In my case, the old adapter worked for 6 months, but then the battery started draining. Obviously something in the adapter went bad.

I took 4 flights in the last few days and the new adapter powered the computer with no battery drain on S80's and a 737.

If it isn't working for you, consider having Apple get you a new one.

I took 4 flights in the last few days and the new adapter powered the computer with no battery drain on S80's and a 737.

If it isn't working for you, consider having Apple get you a new one.

Time to try replacing my adapter, although as mine is not under warranty, it means purchasing a new one.

I see that the MA598Z/A has been replaced by the MB441Z/A. I wonder whether the MB441Z/A is more reliable? Although the old one can be obtained more cheaply, probably safer to go for the new one.

Time to try replacing my adapter, although as mine is not under warranty, it means purchasing a new one.

I see that the MA598Z/A has been replaced by the MB441Z/A. I wonder whether the MB441Z/A is more reliable? Although the old one can be obtained more cheaply, probably safer to go for the new one.

Remember you have 15 days to return it, so hit the Apple store right before your flight and take it back if it doesn't work.

A new model? That's interesting. What could possibly be the difference other than improvements?

A new model? That's interesting. What could possibly be the difference other than improvements?

the difference is the plug at the end. the old one is a straight plug (http://ecx.images-amazon.com/images/I/31XWGIiCJhL._SL500_AA280_.jpg) and its replacement is an L plug (http://ecx.images-amazon.com/images/I/31nbvSCNjvL._SS500_.jpg).

i happen to have both. i use a plastic protective shell on my macbook and although the L plug works, it doesn't have enough clearance for a perfect fit, so i found an adapter with a straight plug on ebay and it's not affected by the shell at all.

i didn't have any problems with either adapter until a couple of months ago. when that started, i brought both adapters to compare and i found no difference between them. if the macbook discharged with one, it discharged with the other. it's something about the planes, since about 1/3rd of my flights it will discharge and the rest have no problems at all.