Rockbox.org home
release
dev builds
extras
themes manual
wiki
device status forums
mailing lists
IRC bugs
patches
dev guide



Rockbox mail archive

Subject: Re: battery discharging wierdness & charging questions

Re: battery discharging wierdness & charging questions

From: Dave Hooper <dave_at_beermex.com>
Date: 2006-03-07

Actually I think I observed this too, on H120. I've seen this twice -- I
think -- it's hard to tell. But only after upgrading to v6 boot code.
Both times the H120 had about half battery capacity before I switched it off
(long hold on Stop..). When I came back to my player several hours later it
would not turn on. After fully charging, and turning on, the player resumed
from a completely different track than the one I had previously been
playing. So I surmise either

1. The H120 didn't actually shut down properly and somehow kept playing
silently to itself until the battery ran down
2. The H120 didn't shut down properly and failed to write the resume
information, and the battery ran down in some kind of zombie
not-quite-switched-off state (although didn't keep playing silently to
itself)
3. The H120 didn't shut down properly (and the battery drained), and
somehow the resume information got corrupted either during this failed shut
down or during the subsequent start up
4. Some 'joker' turned my player on, picked a random track out of my
collection, and left it playing on my desk without me (or anyone else)
noticing.

Unfortunately I cannot rule out 4) but this has happened, twice, in two
different locations! :-) So I think 4 is unlikely.

Which of the other three this might be, I cannot say. But this has only
happened since I upgraded to the v6 boot. Which might be correlation, or
causality, or coincidence. Don't know which.

d

----- Original Message -----
From: "victor rajewski" <askvictor@gmail.com>
To: <rockbox@cool.haxx.se>
Sent: Tuesday, March 07, 2006 11:33 AM
Subject: battery discharging wierdness & charging questions

> Over the last couple of days I have observed the following pattern
> with my H300 rockbox: plays fine for my morning train ride (about 1
> hour), but when I start it up for the return trip in the evening, it
> complains the battery is empty and refuses to boot up. This is despite
> not using it in the meantime. Did not suffer this problem at all last
> week, and the unit is about a year old, so the end of the battery's
> life seems unlikely. So I have two conjectures: one is that it is not
> shutting down properly. Will try to investigate this tomorrow, and
> possible causes.
> The other is that the battery meter is out of whack. I'm not sure if
> this applies to all Li-ion battery systems, but I was under the
> impression that it was good to give such batteries a decent discharge
> every month or so in order to re-calibrate the battery meter. I
> haven't discharged mine for a while, and indeed was finding it
> difficult to work out how to discharge it, as it seems it will shut
> down when the perceived battery level gets to a certain point.
> Apologies if my understanding of this is wrong.
>
> The other thing; does rockbox charge from usb if the battery is
> drained beyond startup voltage? I think I had some success holding the
> record button down while plugging the usb cord in - this went into the
> original firmware's usb charge mode occasionally. Would this be a
> useful feature to have in the rockbox firmware?
>
>
Received on Tue Mar 7 23:20:26 2006


Page was last modified "Jan 10 2012" The Rockbox Crew
aaa