iBook G4 battery load surges

Hello,

My Ibook G4 is 51 months old and now I am having problems I think with my battery though I am fully sure. My battery is in its 256 load-cycle. current battery capacity 58512mAh (original battery capacity: 4400 mAh).

I am experiecing load surges that take my computer from 100% to 1 or 0% and then goes to sleep or shuts down.
The same thing happens when I am charging the computer.. it starts charging and showing 2 or 3% charge and then arises to 100% in minutes.

My computer is also making a noise sometimes when the ring around the feeding cable is in orange color.
I have noticed that by moving the cable around, the color changes to green but it is hard to keep it in that color. I have to play around with it until I find a position that holds the green color and my computer shows as charging.

Could someone enlight me on the possible problem(s)? Do I need to get a new battery or is something else? the noise that the computer makes (like when it is processing information but steady) troubles me...

Thank you!

Below is what my SYSTEM PROFILER says:
Battery Information:

Charge Information:
Charge remaining (mAh): 58320
Charging: No
Full charge capacity (mAh): 58512
Health Information:
Cycle count: 256
Battery Installed: Yes
Amperage (mA): 0
Voltage (mV): 16250

System Power Settings:

AC Power:
System Sleep Timer (Minutes): 15
Disk Sleep Timer (Minutes): 10
Display Sleep Timer (Minutes): 15
Dynamic Power Step: Yes
Reduce Processor Speed: No
Automatic Restart On Power Loss: No
Wake On AC Change: No
Wake On Clamshell Open: Yes
Wake On LAN: Yes
Wake On Modem Ring: Yes
Display Sleep Uses Dim: Yes
Battery Power:
System Sleep Timer (Minutes): 5
Disk Sleep Timer (Minutes): 10
Display Sleep Timer (Minutes): 5
Dynamic Power Step: No
Reduce Processor Speed: Yes
Automatic Restart On Power Loss: No
Wake On AC Change: No
Wake On Clamshell Open: Yes
Wake On Modem Ring: No
Display Sleep Uses Dim: Yes
Reduce Brightness: Yes

Hardware Configuration:

Clamshell Closed: No
UPS Installed: No

AC Charger Information:

AC Charger (Watts): 26
Connected: Yes
Charging: No