Active Topics

 


Reply
Thread Tools
BrentDC's Avatar
Posts: 903 | Thanked: 632 times | Joined on Apr 2008
#21
I see why Nokia uses battery "smoothing".

I whipped up a shell script that polls (a hacked version of retu-adc) and this is what I got:

Code:
8:04 PM - 488
8:05 PM - 474
8:06 PM - 486
8:07 PM - 481
8:08 PM - 477
8:09 PM - 475
8:10 PM - 474
8:11 PM - 472
8:12 PM - 481
8:13 PM - 470
8:14 PM - 470
8:15 PM - 477
8:17 PM - 478
8:18 PM - 466
8:19 PM - 475
8:20 PM - 457
8:21 PM - 479
8:22 PM - 485
8:23 PM - 485
8:24 PM - 490
8:25 PM - 485
8:26 PM - 492
8:27 PM - 492
8:28 PM - 492
8:29 PM - 487
8:30 PM - 492
8:31 PM - 492
8:32 PM - 492
8:33 PM - 493
8:34 PM - 493
8:35 PM - 493
8:36 PM - 493
8:37 PM - 476
I was using the device normally from 8:04 to 8:21, you know, debugging the script, looking up linux commands on the web, etc. Then at 8:22 I went into offline mode, locked touchscreen and keys, and went and took a shower. 8:37 I checked what had happened when I was gone. Wow. I had no idea bettery levels were so unstable. This is something to work with, though.
 
thorbo's Avatar
Posts: 161 | Thanked: 55 times | Joined on Dec 2006 @ SLO, CA; United States
#22
An interesting note... and so far only hypothetical, but rather than "rebooting" I did a shutdown and restart and my battery actually showed more power than when I shut it down... So, it appears that the system looses track of something on the reboot.
 
Posts: 2,102 | Thanked: 1,309 times | Joined on Sep 2006
#23
Well they seem reasonably stable in the period that you were in the shower, obviously the variability in the load (wifi, cpu, backlight) significantly changes the voltage returned by retu-adc. It would be interesting to see the output for the device under constant load (e.g. everything off and trying to sleep, cpu pegged at 100%, wifi on/off, etc.)
 
BrentDC's Avatar
Posts: 903 | Thanked: 632 times | Joined on Apr 2008
#24
I'm trying to come up w/ a better script that puts as little stress on the cpu as possible, so I can get more accurate readings (right now, the script polls retu-adc every minute; I want to build a native C application that just checks the retu value every minute, instead of having to run a whole program).

I'm also thinking of making the output something like CSV so I import it into Openoffice and graph the data.

As for the algorithm, I'm wish I could get the current draw on the battery, to better predict how much time left you have doing the current activity: anyone know how to do this?
 
qole's Avatar
Moderator | Posts: 7,109 | Thanked: 8,820 times | Joined on Oct 2007 @ Vancouver, BC, Canada
#25
I've noticed this phenomenon on both of my N800s, too. I start the reboot with 75% showing on the icon, and I come back into OS2008 with the battery low warning sounding. Once or twice, the tablet has aborted the boot and shut itself off because the battery level was too low... Definitely weird.

I suspect it is something to do with the physics of lithium polymer batteries; my remote controlled planes use these li-poly batteries, and those batteries have very unpredictable lifespans, too.
__________________
qole.org --- twitter --- Easy Debian wiki page
Please don't send me a private message, post to the appropriate thread.
Thank you all for your donations!
 
Posts: 15 | Thanked: 2 times | Joined on Mar 2009 @ Lappeenranta, Finland
#26
Originally Posted by BrentDC View Post
I see why Nokia uses battery "smoothing".

I whipped up a shell script that polls (a hacked version of retu-adc) and this is what I got:

Code:
8:04 PM - 488
8:05 PM - 474
8:06 PM - 486
8:07 PM - 481
8:08 PM - 477
8:09 PM - 475
8:10 PM - 474
8:11 PM - 472
8:12 PM - 481
8:13 PM - 470
8:14 PM - 470
8:15 PM - 477
8:17 PM - 478
8:18 PM - 466
8:19 PM - 475
8:20 PM - 457
8:21 PM - 479
8:22 PM - 485
8:23 PM - 485
8:24 PM - 490
8:25 PM - 485
8:26 PM - 492
8:27 PM - 492
8:28 PM - 492
8:29 PM - 487
8:30 PM - 492
8:31 PM - 492
8:32 PM - 492
8:33 PM - 493
8:34 PM - 493
8:35 PM - 493
8:36 PM - 493
8:37 PM - 476
I was using the device normally from 8:04 to 8:21, you know, debugging the script, looking up linux commands on the web, etc. Then at 8:22 I went into offline mode, locked touchscreen and keys, and went and took a shower. 8:37 I checked what had happened when I was gone. Wow. I had no idea bettery levels were so unstable. This is something to work with, though.
2 questions...

1) someone knows how to translate those numeric values in percentage (%) ?

2) http://mrrau.dyndns.org:23280/n800/kcbatt/ is no longer available (browser goes in timeout)...someone knows were can I find the source code of that application?

i have to do some tests on the Nokia N810 and i have to record the trend of the battery draining...in C/C++ (battery-status is in python, but i don't know how to write the same code in C...)

thanks in advance.

bye bye
 
qole's Avatar
Moderator | Posts: 7,109 | Thanked: 8,820 times | Joined on Oct 2007 @ Vancouver, BC, Canada
#27
Originally Posted by zanne View Post
2) http://mrrau.dyndns.org:23280/n800/kcbatt/ is no longer available (browser goes in timeout)...someone knows were can I find the source code of that application?
You can try grabbing the kcbatt binary from Deblet.

EDIT: Oh, you wanted the source code... Here it is.
__________________
qole.org --- twitter --- Easy Debian wiki page
Please don't send me a private message, post to the appropriate thread.
Thank you all for your donations!

Last edited by qole; 2009-06-03 at 16:49.
 

The Following User Says Thank You to qole For This Useful Post:
Reply


 
Forum Jump


All times are GMT. The time now is 03:35.