[cassioli]

B]self arg can't be coerced to[/b]
What does this error mean?
I get it upon using these commands; it's Jython, but I guess this is a standard Python error:

>>> import javax.power.monitor.PowerMonitor
>>> pm = javax.power.monitor.PowerMonitor
>>> print pm.getBatteryLevel()
TypeError:
getBatteryLevel():
expected 1 arg; not 0

If I specify an argument:
>>> print pm.getBatteryLevel(0)

I get:
getBatteryLevel(): self arg can't be coerced to

[GameDude]

pm = javax.power.monitor.PowerMonitor

You are not creating an instance here. It just assigns the Class PowerMonitor to pm -variable.

pm = javax.power.monitor.PowerMonitor()

I'm not familiar with Jython api, but the code above should make it work unless PowerMonitor requires some parameters. Or you may need to use PowerMonitor.getInstance() since it is used in many Java examples. The error doesn't seem to be very standard though. My desktop Python raises TypeError in both cases and gives better error message with similar code.

What does this error mean?

The first error appears because the method expects 'self' as the first argument. It is given automatically for instance methods but there is no instance here so that's why it complains about 1 missing argument. And the second error means that the '0' you gave is an integer and it can't be converted to PowerMonitor -instance.

[cassioli]

That's right, this is the working version:
>>> import javax.power.monitor.PowerMonitor
>>> pm = javax.power.monitor.PowerMonitor.getInstance()
>>> print pm.getBatteryLevel()

Unfortunately, it always returns same value (0x07fff.ffff); I wonder if some initialisation is required before using this function...
Does any Nokia phone support Javaphone API? Thus I could ask somebody for help...