The simplest is getting the battery level. I use D-Bus to access battery charge percentage level with Python. It's not Maemo specific, but a cross platform API that works on any Linux / FreeDesktop-compliant environment.
Similar API is available through System Information API in Qt Mobility. But I'm not sure how to access Qt Mobility through Python at the moment.
#!/usr/bin/python import dbus bus = dbus.SystemBus() hal_obj = bus.get_object('org.freedesktop.Hal', '/org/freedesktop/Hal/Manager') hal = dbus.Interface(hal_obj, 'org.freedesktop.Hal.Manager') uids = hal.FindDeviceByCapability('battery') dev_obj = bus.get_object('org.freedesktop.Hal', uids) print 'battery percent', \ dev_obj.GetProperty('battery.charge_level.percentage')