Re: Battery depletion on reboot
 

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:

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. :D Wow. I had no idea bettery levels were so unstable. This is something to work with, though.

Re: Battery depletion on reboot
 

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.

Re: Battery depletion on reboot
 

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.)

Re: Battery depletion on reboot
 

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?

Re: Battery depletion on reboot
 

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.

Re: Battery depletion on reboot
 

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

Re: Battery depletion on reboot
 

You can try grabbing the kcbatt binary from Deblet.

EDIT: Oh, you wanted the source code... Here it is.