iPad external battery

Artiom

Artiom

Pre-takeoff checklist
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Artiom
With 10 hours of battery life having backup battery for iPad sounds a little bit paranoid but...
Do you have a backup battery in your flight bag for iPad?
If you do, what kind of battery?
 
Artiom said:
With 10 hours of battery life having backup battery for iPad sounds a little bit paranoid but...
Do you have a backup battery in your flight bag for iPad?
If you do, what kind of battery?
Click to expand...

Ten hours is max. It won't go anywhere close to ten hours with the GPS turned on.

I'd only trust it for three, and carry some way to charge it both in the air and on the ground. Having a 12V aircraft with the oh-so-politically-incorrect cigar lighter, helps in this regard. ;)
 
denverpilot said:
Ten hours is max. It won't go anywhere close to ten hours with the GPS turned on.
Click to expand...

Uh, yeah it does. I've spent several entire days flying with the iPad (and generally with the WiFi, 3G, Bluetooth, and everything else left on and draining the battery) and been fine. That includes Madison to Philadelphia in the 182 (landed with 58% remaining on that one), Houston to Madison in the DA40, Arkansas to Iowa in the Citabria, etc.

I've had mine go 13.5 hours in non-flying situations, so 10 hours is not "max". The iPad definitely lasts longer than I do when flying, and I fly some awfully long days sometimes.

The only time an iPad external battery would really be worthwhile is on trans-Pacific airline flights... Or transoceanic plus some additional stops and layovers.
 
flyingcheesehead said:
Uh, yeah it does. I've spent several entire days flying with the iPad (and generally with the WiFi, 3G, Bluetooth, and everything else left on and draining the battery) and been fine. That includes Madison to Philadelphia in the 182 (landed with 58% remaining on that one), Houston to Madison in the DA40, Arkansas to Iowa in the Citabria, etc.
Click to expand...

Yours is doing better than mine then. Are you at max brightness, and do you let it sleep at all? I can't see mine unless it's cranked up brightness-wise, and I don't let it sleep.

I should have added the caveat that I might push it to four or five hours if I can prove it'll go that long, but I haven't put it to the hardcore test yet.

Each iPad is probably like an individual snowflake. Awww... ;)

(That said, if I can't push mine past 5 hours with it cranked, and you can... I'm callin' up Apple, invoking the Gods of AppleCare and complaining. Heh.)
 
flyingcheesehead said:
Uh, yeah it does. I've spent several entire days flying with the iPad (and generally with the WiFi, 3G, Bluetooth, and everything else left on and draining the battery) and been fine. That includes Madison to Philadelphia in the 182 (landed with 58% remaining on that one), Houston to Madison in the DA40, Arkansas to Iowa in the Citabria, etc.

I've had mine go 13.5 hours in non-flying situations, so 10 hours is not "max". The iPad definitely lasts longer than I do when flying, and I fly some awfully long days sometimes.

The only time an iPad external battery would really be worthwhile is on trans-Pacific airline flights... Or transoceanic plus some additional stops and layovers.
Click to expand...

Kent,

Unless Apple has bucked the trend of giving battery life in optimized numbers (highly doubtful), there's no way you're getting better life than advertised unless its in airplane mode. The advertised battery life is generally with all high-drain functions turned off.

I'll wager that with GPS on, a video playing, and WiFi searching for (but not acquiring) a signal, you'll get 3-4 hours tops (and that's generous).
 
SkyHog said:
Kent,

Unless Apple has bucked the trend of giving battery life in optimized numbers (highly doubtful), there's no way you're getting better life than advertised unless its in airplane mode. The advertised battery life is generally with all high-drain functions turned off.

I'll wager that with GPS on, a video playing, and WiFi searching for (but not acquiring) a signal, you'll get 3-4 hours tops (and that's generous).
Click to expand...

I have read that Apple has recently changed their Macbook battery life tests to be more stringent, and more "real-life." Seemingly away from highly optimized by turning everything off and letting it sit there sucking its thumb. I don't know exactly what they are, but this is what they write on the web page:

Apple is using a new, more rigorous battery test that measures the results you can expect in the real world — like surfing your favorite sites in a coffee shop or catching up on the latest web videos. Even using this new test, MacBook Pro delivers amazing battery life. For your real life.
​
As for the ipad, there are lots of battery life tests floating around in review articles. Here are two non-Apple-fanboy sites:

http://blogs.consumerreports.org/el...ipad-2-battery-life-is-at-least-12-hours.html

http://www.engadget.com/2011/03/09/ipad-2-review/
 
So, if you have 10 hour battery life, and you fly a 9.5 hour trip at night, are you legal? :ihih:
 
My longest trip with iPad included 3 hours of flight time (hobbs) plus preflight and after second leg weather checking, emails and quick internet browsing. I didn't turn off WiFi during the flight. Started with fully charged battery and ended up with 58%. Roughly 13.3% per hour.
This morning I started an experiment - turned WiFi and Bluetooth off, set brightness to 50% launched Skycharts Pro and left iPad close to the window. At the beginning it had 71% of the battery left. Will see how long will it last. If my estimation is correct it should be 5+ hours.
 
SkyHog said:
Unless Apple has bucked the trend of giving battery life in optimized numbers (highly doubtful), there's no way you're getting better life than advertised unless its in airplane mode. The advertised battery life is generally with all high-drain functions turned off.
Click to expand...

To be fair, reviewers are saying that they ARE bucking this trend, heavily, on their laptop models. I just don't know about iPad. I would suspect the opposite with Apple, these days.

I meant to fire up the same testing that some other folks are doing today, and forgot, since I arrived back at the office after only two days off with about 300 e-mails to trudge through (read: DELETED, DELETED, DELETED along with the Strongbad voice commentary.) :cool2:

Now I need lunch. Going to go find a ketchup-less hot dog somewhere. :)
 
denverpilot said:
Yours is doing better than mine then. Are you at max brightness, and do you let it sleep at all? I can't see mine unless it's cranked up brightness-wise, and I don't let it sleep.
Click to expand...

No sleep, but I've only had the brightness on max once - Jesse turned it up while we were standing outside at Gaston's, and I forgot to turn it back down. I did fly to Burlington, IA with it that way - Probably 5 hours - And I got the 20% warning before I remembered that the brightness was all the way up.

FWIW, I've found that max brightness kills the iPad's battery faster than anything else, and frankly it doesn't help that much IMHO. I keep my brightness at the mid-point setting. I don't have any problem reading it in bright sunlight for the most part - If you focus on the iPad itself rather than the pretty clouds in the sky it helps, but in the 182 you shouldn't be seeing sky reflections in it at all - If you are, you need to change the angle at which it's mounted. If it's reflecting off of you, try wearing a darker-colored shirt. (Who knew your shirt could affect your battery life? ;))
 
Did you ever put a non-reflective screen on yours, Kent? Just curious. I don't remember seeing one on yours at OSH. Some people do it, I think it'd be a pain to get all the bubbles out, but have thought about it...
 
denverpilot said:
Did you ever put a non-reflective screen on yours, Kent? Just curious. I don't remember seeing one on yours at OSH. Some people do it, I think it'd be a pain to get all the bubbles out, but have thought about it...
Click to expand...

No. I'd never get all the bubbles out either, though at least one company that sells them includes two in every package so you get one "practice" one to make your mistakes on, and then another one to put on for real.

Eric was the only person at the ForeFlight booth who had one. The problem is not only the bubbles - It completely changes the feel of the screen (harder to move your fingers due to more surface texture). I didn't like it.
 
4 hours 20 minutes it is down to 13%.
So average rate is 10% per hour FWIW
BTW I have removed SIM card from my iPad since I don't use 3G data on it and want to make sure 3G modem doesn't waste any power.
 
Artiom said:
4 hours 20 minutes it is down to 13%.
So average rate is 10% per hour FWIW
BTW I have removed SIM card from my iPad since I don't use 3G data on it and want to make sure 3G modem doesn't waste any power.
Click to expand...

Pretty sure the 3G chipset doesn't power down just because the SIM is gone. Settings -> Cellular Data -> Off would do it, though.

I think the key from Kent here is the screen brightness. I used mine for an hour and a half straight today on max brightness and it's at 67% after a 100% full overnight charge last night. I have 3G off, since I don't pay for the service, but for that 1 1/2 hours (actually even now... it's still connected) it's been using the iPhone as a Personal Hotspot.

15:00 - 16:30 was when it was used, it's 17:22 now and the screen had gone to sleep after that usage, and it's at 67%. Max brightness on the screen, WiFi on.

I think I'll fire up Foreflight and leave it running and see if it makes it all the way to my house at roughly 19:00 Mountain tonight. GPS on, of course.
 
20:00 and it's down to 22%.

Roughly two and a half hours ate 42% of the battery.

No cellular, WiFi on, max screen brightness, Foreflight running with GPS on.
 
denverpilot said:
20:00 and it's down to 22%.

Roughly two and a half hours ate 42% of the battery.

No cellular, WiFi on, max screen brightness, Foreflight running with GPS on.
Click to expand...

Are you trying to determine useful battery life for in-flight operation? If so, I would think WiFi off would be the better test. Unless you're war flying, that is... :D
 
Kent said he flies around with his with everything on and gets some impressive numbers. So I'm attempting to duplicate but changing one variable... That the brightness is all the way up. Technically I'm changing two variables since I have the cellular data turned off, but now that I think about it, without confirmation I really don't know if that really de-powers the cellular chipset. I'll say it does for now.

20:50 and 8% left.
 
denverpilot said:
Died at 21:13 still showing 2% when it shut down. ;)
Click to expand...

Yeah, since the iPhone shuts down very shortly after the 10% warning I was expecting the iPad to do the same - Not so. First day I had it, I got it to 10%, thought "Ooooo, time to kill it dead!" and started playing The Matrix at the lobby scene. I finished the movie and it still hadn't shut down! I had to mess with it for a while longer.

I pretty much expect it to shut down at 2%, but I have seen it at 1% so I'm not sure exactly how/when it decides it's done. Never had it shut down over 2%.

So Nate, turn the brightness down to half, charge it up, and try again tomorrow.

The next day, turn off 3G data, WiFi, and Bluetooth and see what you get.
 
flyingcheesehead said:
So Nate, turn the brightness down to half, charge it up, and try again tomorrow.

The next day, turn off 3G data, WiFi, and Bluetooth and see what you get.
Click to expand...

It's on its way up... 22% already. ;)

Bah! I completely forgot about Bluetooth.

I only use it once in a while for a paired Apple Wireless Keyboard, and completely forgot it was on. It's off for tomorrow's test.
 
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denverpilot said:
Kent nailed it. 1/2 Brightness extends the battery life immensely. :wink2:

http://dl.dropbox.com/u/3597579/iPadBatteryTests2.pdf

Nine hours! Very cool. :D
Click to expand...

9 and a half! Now if you turned off WiFi too, you'd probably do 10 or better even running the GPS all day. :)

The brightness seems to affect the battery life far more than anything else. I'm also kind of wondering if keeping the brightness at, say, 80% would make a big difference from 100% too.
 
denverpilot said:
Here's today's results. Almost perfectly linear (the non-linearity of yesterday's data was due to Numbers being retarded about Time scales).

Kent nailed it. 1/2 Brightness extends the battery life immensely. :wink2:

http://dl.dropbox.com/u/3597579/iPadBatteryTests2.pdf

Nine hours! Very cool. :D
Click to expand...

Goes to show how inefficient CFL backlighting power supplies are. Even white LEDs consume a bunch of current to do their thing.
 
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