the problem with airplanes and the MBP

Question

the problem with airplanes and the MBP

I'd be interested in whether people think this problem is specific to my machine, or general.

I do too much travel on planes. I therefore couldn't begin to use my MPB until I could buy 3 batteries (about a month after I got the machine), and I also had to buy an inverter, since I couldn't find any iGo like tip to connect to the new magnet connection.

The first inverter I got was a Targus. It promised 90w - above the reported 85w drawn by the machine. Four flights, never would it work. Everytime, it would trip because too much power was demanded. I then bought a "CyberPower" inverter, promising 120w. That worked for a good 3 hours on an internatinoal flight, but then it began flaking as well. I then discovered that if I had a fully charged battery (so it wasn't trying to charge), it worked fine. So the obvious "solution" is either to have a fully charged battery, or to remove the battery -- though that's obviously a bit dangerous, since the cord disconnects from the laptop so easily.

This is a big problem with the machine. Is it just mine, or is it general? And is there any useful way to control how much power the unit draws? Notice, the processor speed control has been removed from the Energy Saver panel.

MBP Mac OS X (10.4.5)

PB G4, Mac OS X (10.3.6)

Posted on Mar 29, 2006 3:55 PM

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Answer 1

Mar 29, 2006 4:05 PM in response to Lawrence Lessig

I recently picked this up:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6862501825

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Answer 2

mcowger

Level 2

420 points

Mar 29, 2006 5:21 PM in response to Lawrence Lessig

You have to factor in the inefficieny in an interverter as well.

Most are less than 60% efficient, so you should size your inverter for a 85 W adapter so that it can deliver at least 150W.

Also, the fact that they don't do a good job of outputting a real size wave (its usually more stepped square wave), also increases the effective load.

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Answer 3

Mar 30, 2006 1:48 AM in response to mcowger

But then is there a way to have power on an airplane with a MBP?

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Answer 4

Mar 30, 2006 9:24 AM in response to Lawrence Lessig

Dr. Lessig: I can't vouch for these personally, but others have posted that these Statpower inverters have worked for them:

http://www.dsmiller.com/html/Electronics-Mobile-Audio-Power-Inverters-XPOWER-POC KET-175.htm

Most inverters on the market hit the 90% mark under low/moderate loads, good ones stay close to that under full load. Cheap models may drop down to 50-60% efficiency under full load, but those are the bottom of the barrel and should be avoided. Still, if you were attempting to use a 90W adapter, it's likely it won't cut it for a device drawing 85W. But a 120W adapter should be able to handle it, unless it's sub-par in some way. This one is 175W, so I'd hope it would be more than sufficient.

I don't know the efficiency stats on this particular model, but Statpower has cheaper car inverters that run at about 90% efficiency, so I'd guess that this one is at least as good.

I'd be curious to know what the true max power draw is for the MacBook. The Apple inverter is rated at 85W, up from 65W for the PowerBook, so I'd guess that it's somewhere between 50-70W.

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Answer 5

Mar 30, 2006 9:37 AM in response to Lawrence Lessig

In terms of limiting the power draw of the machine, I'd do the same things people do to reduce battery draw: turn off any unnecessary radios (Bluetooth, WiFi), turn down the screen brightness, do whatever Energy Saver options are available (spin down disks when possible, use "Better Energy Savings" option, etc.). But I'd still seek out an adapter that can power the MacBook on full demand, to be safe.

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Answer 6

Apr 2, 2006 9:58 AM in response to jim farley

I'll try the 175 watt version (third inverter purchased for this machine), but it would also be very cool to have a software way to turn off battery charging.

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Answer 7

Apr 2, 2006 10:20 AM in response to Lawrence Lessig

This is REALLY getting old. I travel a lot and I need a car/airplane adaptor! This is a portable laptop right? I am at a loss as to how the MacBook Pro Product Manager could let this situation go for so long. There should have been an Apple solution at launch or an agreement with one of the major suppliers to have a product shortly after. This has gone on too long and forced me on more than one occasion to revert back to my PowerBook. I've already written to every manufacturer I can think of. I hoep all of you are too!

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Answer 8

Apr 10, 2006 9:50 PM in response to Lawrence Lessig

I just flew internationally on a plane with AC power so thought I could work on the flight. However, the power is limited to 75W and shuts off for the MBP. I think this is a pretty general restriction.

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Answer 9

Apr 26, 2006 11:20 AM in response to Lawrence Lessig

I recommended the Kensington Ultra Portable Power Inverter 150 to someone. It didn't work. The light on the inverter was green, but would switch to red as soon as the A/C brick was plugged in.

Are there any other recommendations?

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Answer 10

Amore

Level 1

6 points

Apr 27, 2006 6:49 PM in response to JHalvorson

Same happened to me. I was on 4 planes this week and the inverter did not work with my mbp. It is really frustrating as I am finding a few things that are reason to return my mbp. Any suggestions? My major problems are about airline converters, isight not working, audio chat not working....

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Answer 11

May 2, 2006 4:15 AM in response to Lawrence Lessig

I just discovered that the AC adapter on planes will work with the MBP IF you have a fully charged battery. As long as it is just powering the MBP, the power drain must be low enough that the overload switch does not trip. With a 1/2 charged battery, it tripped right away.

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Answer 12

iFelix

Level 8

35,155 points

May 2, 2006 5:00 AM in response to William J. Raduchel

Or remove the battery.

You don't need the battery to run the MBP when powered by AC.

iFelix

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Answer 13

May 2, 2006 6:28 AM in response to iFelix

No, but you’re vulnerable to power interruptions, including the disconnection of the MagSafe, in ways you are not when a battery is installed.

If you’re going to do this, be very careful not to let the MagSafe connector disconnect.

Randall Schulz

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Answer 14

May 2, 2006 9:41 AM in response to William J. Raduchel

Just as a data-point, I used a CyberPower 120w inverter to power my MBP (with fully charged batery) for many hours on an international flight last week.

On the way back I was on Lufthansa, which had 110v ac outlets right in the seat... but it wouldn't stay on for my MBP no matter what... I suspect the limiter was very sensitive.. after I tripped it 5 times it stayed off for the entire flight.

It would be nice to have a bootup key that put the MBP in "very low power consumption" mode or something...

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Answer 15

May 3, 2006 8:03 PM in response to Lawrence Lessig

Purchase a Kensington Ultra Portable Power Inverter 150 at your local Apple Store or on-line.

Provides 150 wats to a standard North American power plug. The MBP only uses 85w, so you've got power to spare.

Works in cars & planes (don't know 'bout trains... 😉

R...

MBP Mac OS X (10.4.6) PB's & iB's too!

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