Rockbox

  • Status Closed
  • Percent Complete
    100%
  • Task Type Bugs
  • Category Drivers
  • Assigned To
    linusnielsen
  • Operating System
  • Severity Low
  • Priority Very Low
  • Reported Version Daily build (which?)
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by mouendag - 2004-02-11
Last edited by bagder - 2005-03-09

FS#2002 - Battery runtime and trickle loading bug?

Jukebox Recorder

Sharing other experiences about the short run-time of
my batteries, I did some tests and have the following
observation:

After having used the Archos for a while, and put the
charger in while it was on. It started loading.
Next morning to my surprise, the battery was not
showing a FULL status, and it was not loading either.

Debug - View IO - Battery 84%
Debug - View Runtime - 2h 14 m
Debug - View Battery - shows typical discharging 

process
Conclusion: It stopped charging in the middle of the
night.

I unplugged the Archos from the charger, turned it off,
then turned it on again, and put the charger plug in
again. IT DID NOT START CHARGING.

I switched to the Archos 1.28 load, put the charger plug
in, and it started charging immediately until 100%

Second observation:
With a full battery, put the charger in. Also connected
the Archos to my PC. After a while shut down the PC.
The battery shown on the status bar is 100%.

Debug - view IO - Battery 5.27V, 100%
    (not OK, since 100% loaded voltage is 5.44)
Debug - view runtime - 0h 0m  (OK)
Debug - view battery - shows discharge pattern

Unplugged the Archos, OFF, ON, plugged in the charger,
and it started charging.

Debug - view IO - Battery 5.09V 

After a while the -view Battery- graph shows a
sinusoidal pattern, topping off above 5.35V, and starting
to show regular “spikes”, proof of trickle charging, and it
has been sitting at between 5.45 and 5.48V for a few
hours now. So normal behaviour.

Conclusion: Some condition makes trickle charging not
work correctly.

RockBox CVS 040203
Archos JR 1.28
Mask 0×0302 Settings: Deep Discharge: NO

            Trickle charge: YES
            Capacity: 1800mAh
            Car adapter mode: NO

Very pleased with the added functionality to my Archos.
Unbelievable effort that must have gone into this, and at
a very high quality. !! You’re the best.

Closed by  bagder
2005-03-09 10:39
Reason for closing:  Fixed
Additional comments about closing:  

Logged In: YES
user_id=1110

Try a recent daily build. The charging algo has been
revamped a lot.

Project Manager

Interesting. Maybe Rockbox fails to restore the settings in
some cases, and ends up in Deep Discharge mode…? Hmmm….

Project Manager

This is supposed to be fixed in the daily builds. Can you
verify this?

Linus,
Charging works OK, though I suggest some improvements to
the algorithm and default values for voltage levels.

1) When fully charged, the battery is NOT FULL. You can
further charge with Archos 1.28 for yet 1.5 hours. Though
the effect on the voltage level after a "cool down" period of a
few hours, is minimal.
2) Trickle charge takes a big swing, and the low-voltage
starting point of 85% is far too low. Also remember that the
percentage is a derived and corrected value and not
absolute. (e.g. after 1 hour of playing, it still reads 100%)
3) The voltage readings are not stable (at least not on my
box), and the last digit rapidly swings about .05V

Following are some constants in the source code:

#define BATTERY_LEVEL_FULL 585 /* 5.85V */
#define CHARGE_END_ZEROD 50 /* stop when N minutes
have passed with

  • avg delta being < 0.005 V */

#define CHARGE_RESTART_HI 85 /* %: when to restart
charging in 'charge' mode */

                               /* attention: if set too high, normal 

charging is started in trickle mode */

#define TRICKLE_VOLTAGE 545 /* which voltage is best?
(centivolts) */

I propose you make the value for FULL a configuration
setting, either manually entered or automatically determined
as the highest read in "charging" a test-run.
Or… Why bother at all? Keep charging until the average
voltage over a period of e.g. 10 minutes is constant.
(measurement being an average read (take care of my last
digit's always changing))

CHARGE RESTART for trickle load should be much higher than
85%, and preferrably a voltage related to a "full charge"
voltage (that you could store as a configuration setting).

Reason: With the discharge curve of a typical battery, the
first few hours of playtime the battery voltage level will not
drop substantially. After that it becomes an almost straight
line.

Hope this helps,

Regards, Martin

Linus,
Charging works OK, though I suggest some improvements to
the algorithm and default values for voltage levels.

1) When fully charged, the battery is NOT FULL. You can
further charge with Archos 1.28 for yet 1.5 hours. Though
the effect on the voltage level after a "cool down" period of a
few hours, is minimal.
2) Trickle charge takes a big swing, and the low-voltage
starting point of 85% is far too low. Also remember that the
percentage is a derived and corrected value and not
absolute. (e.g. after 1 hour of playing, it still reads 100%)
3) The voltage readings are not stable (at least not on my
box), and the last digit rapidly swings about .05V

Following are some constants in the source code:

#define BATTERY_LEVEL_FULL 585 /* 5.85V */
#define CHARGE_END_ZEROD 50 /* stop when N minutes
have passed with

  • avg delta being < 0.005 V */

#define CHARGE_RESTART_HI 85 /* %: when to restart
charging in 'charge' mode */

                               /* attention: if set too high, normal 

charging is started in trickle mode */

#define TRICKLE_VOLTAGE 545 /* which voltage is best?
(centivolts) */

I propose you make the value for FULL a configuration
setting, either manually entered or automatically determined
as the highest read in "charging" a test-run.
Or… Why bother at all? Keep charging until the average
voltage over a period of e.g. 10 minutes is constant.
(measurement being an average read (take care of my last
digit's always changing))

CHARGE RESTART for trickle load should be much higher than
85%, and preferrably a voltage related to a "full charge"
voltage (that you could store as a configuration setting).

Reason: With the discharge curve of a typical battery, the
first few hours of playtime the battery voltage level will not
drop substantially. After that it becomes an almost straight
line.

Hope this helps,

Regards, Martin

Like I suggested, it may be the settings (tricke restart at
85%) and the algorithm. I did not see it go into deep
discharge/charge mode.

Wish I could help improve the algorithm, but I have very little
time available nowadays. (which is good).
Thanks..

Project Manager

Try a recent daily build. The charging algo has been
revamped a lot.

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