[libnds and/or PAlib] Get battery level, if charging, volume

[xem]

Hi,
I'm quite a beginner in DS dev, and use PAlib (for now)
for a project, I need to access to some unusual information,
I would like to know
- If the DS is currently charging or not
- If the battery level is high or low
- And the sound volume
According to GBAtek, a DS registry represents the volume,
and battery/charging status seem to be part of something called IPC.
Some old homebrews could use these data, even on PAlib, but with the current versions of libnds/Palib, I can't do it as easily as they did.
Can someone help?
Thanks!