Running a laptop minus battery

I have an old Sony Vaio laptop (PCG K215B) whose battery no longer retains charge for more than a few minutes. Question: is it safe to run the laptop without the battery installed? Or is the battery used in some way by feedback circuitry (rather like a super-capacitor) to control the supply voltage from the mains-powered brick? I don't want to risk over-volting the laptop, nor do I wish to lose any user settings if the battery is relied on for data retention.

Thats a good question. I have always just left the old battery in. I never even thought about trying it without it. I think without it the laptop will keep nagging at you.

My Dell runs just fine sans battery. It does tell me there is no battery but it runs fine. This nay vary from laptop to laptop though.

Ron