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Subject: Do you have an FM Recorder? Help me with measurement values for charging code!
From: Uwe Freese (
Date: 2003-01-26


I wrote the current charger code and I read here that charging is not
working correctly with FM Recorder because of the LiIon battery. I'm
willing to change/add the code needed for the FM Rec., but I need some
So if you have an FM Recorder, you can help me:

- What is the maximum voltage the LiIon battery has when it's full?

- What is the voltage when the original Firmware shut's off the AJB and
  says it's empty?

- Charging LiIon is usually charging with a constant voltage. It may be
  that the FM Recorder has an other circuit in it and it charges the
  battery the whole time (when charger plugged in).
  Can someone measure if the battery is charged the whole time with the
  original firmware? (measure the charging current and the voltage if
  the battery is already full)

- To show the correct battery level percentage, I need voltage values
  over a complete decharging cycle.
  Please charge the battery with the original firmware, unplug the
  charger, start Rockbox, play back music and go to the debug menu
  (battery menu). Write down at about 20 voltages over the complete
  decharging cycle like this (it needn't be exactly the same intervals):

  0:00 5,5 V
  0:35 5,4 V
  1:02 ...
  10:00 4,5 V (shutoff)

Thanks for your help!
Bye, Uwe.

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