October 14th, 2009

Spitz / Zaurus C-3000 power questions

I did some measurements of spitz battery subsystem; maybe they are
useful for someone.

Unfortunately, concistent numbers are quite hard: longer/thinner
cables mean lower voltage and also lower currents :-(. I get quite
consistents 5V at power supply, but it goes down to 4.5..4.2V when it
reaches zaurus behind ampermeter. (Is zaurus even able to charge
battery properly from such low voltage?)

One big surprise was wlan CF card, eating +200mA when initialized.

I'm working on drivers/power/spitz_battery driver, and I'll need to
know conversion between ADC readings and milivolts; does someone have

Does someone have better/more reliable/other power consumption numbers?

Idle, charging, no backlight, linux 2.6.26: 200mA @ 4.8V
                bl 1:                   310mA
                bl 10:                  315mA
                bl 20                   340mA
                bl 30:                  390mA
                bl 40:                  440mA
                bl 47:                  445mA
disk is spinning:                       +50mA
find /:                                +200mA
cat /dev/zero:                         +100mA
make:                                  +240mA

charging, powerdown:                    380mA..440mA
charging, ROM menu:                     550mA
D+M monitor, not charging:              170mA
D+M monitor, half charging:             280mA
D+M monitor, full charging:             480mA..550mA

Charging in ROM, from empty @ 8:35:     610mA
                              8:38:     555mA
                              8:45:     545mA
                              8:50:     540mA
                              9:01:     540mA
                              9:18:     530mA
                              9:36:     520mA
                              9:45:     505mA
                              9:51:     480mA
                             10:15:     365mA
                             10:48:     250mA
                             11:01:     225mA
                             11:31:     180mA
                             11:38:     170mA
                             12:48:      80mA, charger LED is off.

Measured @ li-ion battery.
ROM                                     <7mA
Linux 2.6.26 suspend:                   7.5mA, 10mA?!
Linux 2.6.26, fully running, charger connected: 50uA :-(
                                                100mA charge