Battery-life - Watching Movies on the Pandora


tax0r

Still Fresh
Joined
Mar 12, 2012
Messages
6
Location
Germany
Hi,


I'm very interested in the Pandora and planing to get one. But before I do so, I'd like to ask a few question about the battery-life:

  • What are realistic times for one full charge (normal setting, I guess 50% brightness, wifi on, surfing + videos would be normal for me, but correct me if known better)?
  • How long can you watch movies on the Pandora? (I'm a real movie-fan and coding them new may be annoying but I would do it.)


Any experiences? Or further questions?


All the best,


tax0r
 
With WiFi? Somewhere around 8 hours I'd guess from my experience with it, maybe a bit more, probably not less. Movie playing? Well, that'll probably load the system quite a bit unless the DSP is in use. Without DSP and WiFi off? 9 or 10 hours would be my guess, doubt it would be any less. Based on my experience using the pandora, but I've never actually used it for that for an entire charge.


Also; please note that flash on the pandora is a bit wonky to say the least, so using flash to watch clips is not something to expect. 240p on youtube seems to work fine with some overclocking, but no more that. 360p works in minitube, but for 480p, the DSP would be needed.


Also; the WiFi build into the pandora is quite picky about the APs it likes, so keep in mind that you might not be able to use the built-in one for your purposes (although there's cheap tiny USB WiFi-sticks from china that works fine in the latest firmware, and afaik, they don't use more power than the build-in WiFi). I can get a steady 400 to 500 kB/s transfer speed with my AP, but on IRC, comments on that seems to indicate that I'm pretty alone with that.


Also; I would not suggest using USB harddrives for watching your movies on the go. USB 2.5" drives are known to not follow the USB power specification, and some might even fry the USB-port, while some are reported to work fine. Something that applies to those that works are that they will drain your battery _fast_, I wouldn't expect more than 4 hours battery life with a USB HDD connected. Unless it's powered by an external source. A 1.8" drive would probably work fine, although still a bit of a battery drainer.
 
  • What are realistic times for one full charge (normal setting, I guess 50% brightness, wifi on, surfing + videos would be normal for me, but correct me if known better)?
6 hours of continuous use from 100%. I do this regularly. My Pandora is basically my defacto remote administration tool these days. On days when I close the lid when I'm not actively using it I can get up to 10 hours.

  • How long can you watch movies on the Pandora? (I'm a real movie-fan and coding them new may be annoying but I would do it.)
With the wifi off, expect 10 hours. I've never watched a full 10 hours of video, but I have watched about 3 hours of video on a bus trip before and the battery gauge (which I know to be reasonably accurate, within about 5% over the full range) only went down about 30%.
 
Sounds great! Will be doing quite some traveling the next few months with lots of sitting around.


Didn't yet check which codec would be the best to use, but thought about some avi-codec and vlc. I think I can get 1,5 hours of video down to 300-500mb. Would use SD's instead of an HDD, they just fit anywhere (easy to transport). I'll check out wiki for a support SD-card-type.


PS: Thanks for the quick answer!
 
Last edited by a moderator:
6 hours of continuous use from 100%. I do this regularly. My Pandora is basically my defacto remote administration tool these days. On days when I close the lid when I'm not actively using it I can get up to 10 hours.
Experimental kernel should give quite a bit of extra time for this usecase.
 
Last edited by a moderator:
I used it to keep me entertained on a long train ride (about six and a half hours). I stuffed a USB stick full of Simpsons and Star Trek episodes and watched it almost non stop the entire trip. It was charged to 89% when I turned it on and it could easily have kept going for another hour when I got off the train. Screen brightness was at around 50%. :D Love this thing!


The best part was when the the guy next to me (also watching videos) had to turn off his netbook because his battery was out of charge. ^_^
 
I used it to keep me entertained on a long train ride (about six and a half hours). I stuffed a USB


The best part was when the the guy next to me (also watching videos) had to turn off his netbook because his battery was out of charge. ^_^

:) ^_^ B)
 
Sounds perfect! How did you code the video / what player did you use?


Read from PSP-Users, that they underclocked their CPU to the lowest MHZ possible to save battery. Therefore they used a balanced thing (compression<->filesize). Would be interesting how far it can be pushed ... even though 8-9 hours beats anything I need.
 
I'm getting 25 hours of music, 12 hours of wifi-surfing, 20 hours of lite desktop work on the experimental kernel.


Playing music in GMU.
 
I'm getting 25 hours of music, 12 hours of wifi-surfing, 20 hours of lite desktop work on the experimental kernel.
:eek:


:blink:


FFFFFFFFFFFFFFFFFFFFFFFFUUUUUUUUUUUUUUUUUUUUUU----


My brain just exploded from the idea. I was thinking maybe a few hours more, not double. I really need to check out this experimental kernel.
 
Well, there's a DSP in there that can handle 480P(the screen's resolution) H.264 Baseline without using too much power, but that requires setting aside 64MB of the 256MB available (even when not in use), and the main OS doesn't support it. I can find packages for Gentoo though.


The Pandoras that are now being built have 512MB though, so loss of that 64MB is less of an issue, and more worth it getting the DSP to work. It'll require a GStreamer-based media-player as that's what TI's code provides.


Not utilizing the DSP, xvid should be fine, or you could use something even less heavy if storage isn't much of an issue.


But I can't be sure, as I don't have a Pandora yet...
 
Can anyone estimate the battery life playing audio though the DSP yet? or will we only know when someone tries?
 
tumblr_ldo4afK5V51qb4uc0.jpg
 
Not utilizing the DSP, xvid should be fine, or you could use something even less heavy if storage isn't much of an issue.


But I can't be sure, as I don't have a Pandora yet...
With just the CPU, xvid is excellent up to 720p, and h264 can be decoded up to 480p reasonably well with occasional frameskip; testing done at default 500mhz.


If you're transcoding anyway, 480p xvid/divx is probably the best choice.


But for audio, we won't get anywhere close to that 28 day estimate. There's way more than the DSP to contend with. I'm pretty sure the DAC will use some, the speakers aren't free, and the SD/CPU when it loads the next song into RAM need to be accounted for.
 
As for audio, TI mentioned 22mW when using the DSP in this document. I doubt we'll ever reach that, but that'll give 28 days of music...

5119503128_Shocked_answer_1_xlarge.jpeg



If we can only reach a tenth of that, we have some seriously competitive media playing there; that can outlast my D2 :blink:
 
Last edited by a moderator:
6 hours of continuous use from 100%. I do this regularly. My Pandora is basically my defacto remote administration tool these days. On days when I close the lid when I'm not actively using it I can get up to 10 hours.
Experimental kernel should give quite a bit of extra time for this usecase.

Do you have a link to where we can read more information on and acquire the, 'Experimental kernel'?


Thanks!
 
Back
Top