[cosurgi]

You guys already have several fully working prototypes with battery included, so I'm surprised that search didn't turn up anything.

Just leave one pandora on for the night, and tell us what's the battery life on idle, then do it with 'mplayer -loop 0 file.avi' to play something in infinite loop and tell what's the battery life playing movie. Or with some game intro scene running in infinite loop.

Pretty please

[borgqueenx]

depends on how battery-saving the media player will be.
Expect about 10 hours. Now close this thread please, i have made a topic about this about 2 months ago.

[lulzfish]

But did we get a conclusive list of battery lifes?

All I've heard is "8 hours, full CPU use".

I want something like:
1. Idle
2. Running some background programs like IM, maybe leaving a Firefox session open
3. Running at low CPU usage, like a screensaver
4. Movie playing
5. Sound playing

And variations with the screen on and off and such forth.

[VRAndy]

Expect about 10 hours. Now close this thread please, i have made a topic about this about 2 months ago.

So we're not allowed to talk about an important feature of Pandora? Why not?

The "10 hours" thing comes from estimates.
Cosurgi was asking if real data was available yet. That's a perfectly valid thing to ask about.

Just leave one pandora on for the night,

It's not quite so easy. They'd have to check on it from time to time, or otherwise do something clever. Afterall, you know the battery will die eventually, we want to know when!

[fischju2000]

Well a timing program that writes how long it's been running every 30 seconds to the SD card should be sufficient. The bitrates of movies would also have an effect, standard AVI vs x264.

[GeneralZod]

Just leave one pandora on for the night,

It's not quite so easy. They'd have to check on it from time to time, or otherwise do something clever. Afterall, you know the battery will die eventually, we want to know when!

Just logging to a file every minute or so should do the trick

e:f;b

This post has been edited by GeneralZod: 12 June 2009 - 05:54 PM

[Aethix]

I think I have heard somewhere that it gets around 100 hours of battery life with it doing nothing but playing music. I am only reporting what I may or may not have heard.

[gp2.eXe]

i have made a topic about this about 2 months ago.

Well, it was expected that a new thread would show up in about two months™.

Edit:

Just leave one pandora on for the night,

It's not quite so easy. They'd have to check on it from time to time, or otherwise do something clever. Afterall, you know the battery will die eventually, we want to know when!

Just logging to a file every minute or so should do the trick smile.gif

e:f;b

Very true, the GP2X had a testing utility that would do exactly that.

This post has been edited by gp2.eXe: 12 June 2009 - 05:58 PM

[(naw)mcx]

I think I have heard somewhere that it gets around 100 hours of battery life with it doing nothing but playing music. I am only reporting what I may or may not have heard.

This is possible using the DSP(I think) on it's own. I don't think we can do that though, at least at the moment, due to the lack of drivers/codec.

[VRAndy]

Just logging to a file every minute or so should do the trick

Good thought. Perhaps even just setting mplayer to '-msglevel 9' then piping the output to a file would be close enough.

[Nation.A.List]

depends on how battery-saving the media player will be.
Expect about 10 hours. Now close this thread please, i have made a topic about this about 2 months ago.

Sorry, but who the hell are you to dictate what will be discussed ?

[urjaman]

I think I have heard somewhere that it gets around 100 hours of battery life with it doing nothing but playing music. I am only reporting what I may or may not have heard.

That's a calculation based on that one can turn off/suspend/stop
- Cortex A8
- LCD
- DDR sdram (slow refresh)
- and everything else unnecessary...

And then decode MP3 from the internal 64k SRAM using the DSP and play it (i dont remeber whether the DSP can play it out directly, i think so).
Every 64k or so the Cortex would need to wake up to load more data from sdram and/or disk, then sleep again - otoh it would be possible to atleast do the load from sdram by using only the DSP, i think.

Anyways, there's no software for this (yet).

[skeezix]

Something to consider is how apps are written .. up front I imagine most won't be leveraging the hardware very well. ie: an ipod runs for only a few hours when playing music using the cpu. but when using the hw decoded and letting the cpu idle, they run for bloody ever.

Not that I've been watching that side of things, but I doubt we'll be 'there' yet, but again I've not watched.

(The stuff I've paid attention to is the panda is a _beast_ for performance

jeff

[MWeston]

I have an EVM for the battery fuel gauge so I can connect that to my laptop and log the battery draining from start to finish through the USB port so it doesn't matter if the Pandora board shuts down on its own when the battery is empty. I still haven't done a full charge to empty cycle all at once but the fuel gauge learns the battery profile and was predicting the usual 8.5-9 hours. Since I have run the battery down over a couple of days with my testing, the prediction is accurate as the battery capacity is at or above the rating given by the manufacturer.

The load doesn't change much whether you idle at the desktop or run an emulator or app. I think the change is around a 50mA range based on processing and how quickly the pixels are changing so doing pretty much anything with just the CPU core is going to perform about the same. Average power with the LCD at full brightness is around 1.6W. Adding the SGX core into the mix (like with Quake) added another 30-60mA of drain I think. It fluctuates with what's going on. It's been a couple of months since I have run these tests but the hardware hasn't changed to affect new results with production boards so this is all still valid.

What really changes the power usage is when the LCD goes off, cranking up the internal speaker volume or plugging something into the USB port (a simple mouse or keyboard will decrease battery life by 22-25%. That's how little the whole system uses!). If you slow the clock for things that don't need it (I run Picodrive at 200MHz in Angstrom for example), you get the 10 hour life and if I turned down the LCD brightness it would be a bit more.

When the LCD goes off and I'm playing music, the battery life was in the 12 to 15 (if I remember to slow down clock) hour range. We still don't have power management in the code so everything is lit up, the core is running at the voltage for 500MHz and the clock was usually at 500MHz so there is all kinds of room for improvement. If an N900 or Palm Pre can run all day on an 1100-1500mAh battery (maybe?), we should be able to do way better with 4000mAh. The hardware has the capability to shut down anything not in use so it's purely a software effort needed. We only have one person volunteering to work on the power management code right now so software seems to develop at a slow serial rate with the extra stuff like this.

EDIT: I also don't recommend going around boasting a 100 hour battery life playing music. As some people have pointed out, getting anywhere near that will require some serious talent to code. That might be a community project some day but no one should count on that as a launch feature to shame your iPod buddies.

This post has been edited by MWeston: 12 June 2009 - 06:23 PM

[WhiteBat]

thanks MWeston. this is something i was also curious about, but never wanted to ask.