My laptop rus slow on battery

[Jojo]

When I start the system on Battery it's very slow!
On startup I must wait 10 minutes to the Logonwindow.
If system is working on A/C external works great, but if I removed A/C power goes slow again.
I think the problem is since the beginning, but I haven't noticed that.

Can anyone help me?


My specs:
HP Notebook NX6325
Mac version 10.5.3 AMD Zyph & LEO4ALL
AMD Turion(tm) 64 X2 TL-56 (1,8 GHz)
2 GB DDR2 / 667
ATI Radeon Express 1150
ATI SB400 S-ATA (60 GB HDD, DVD-RW)
Lan card (Broadcom 57xx)
Wireless card (Broadcom BCM43