How do I take the CMOS battery out of a laptop?

October 17, 2006 7:08 PM

How do I take the CMOS battery out of a laptop?

I have an NEC Versa C160 that needs its BIOS password reset. I've been told one of my few options is to remove its CMOS battery for around 10 minutes. How exactly do I do this? Has anybody had experience doing something like this before? What exactly am I looking for? I don't want to brick this machine or cause some other problem. I'm handy enough with a screwdriver though.

posted by sjvilla79 to Computers & Internet (3 answers total)

Best answer: You pretty much do it like you do in a desktop, only much more carefully and much more slowly: keep unscrewing stuff and taking it out until you dig your way down to the motherboard, then find the battery, uplug it for long enough for the RAM to lose its charge, and plug it back in. Most often it is under the front half of the laptop, in front of the keyboard. You're looking for something like this or this or this.

You can't brick a computer by cycling battery power. You can VERY EASILY brick it in any number of other ways while you're in there: plugging the battery back in backwards, plugging other cables back in imporperly, scratching the motherboard, improperly re-installing CMOS BIOS boot ROM, etc etc etc.
posted by ChasFile at 9:07 PM on October 17, 2006

Also, it doesn't take 10 minutes to reset the CMOS. You need only remove the battery for more like 10 seconds or so.

You will need to set the CMOS reset jumper though. Simply removing the battery won't necessarily reset things.
posted by doomtop at 7:43 PM on October 18, 2006

Response by poster: I fixed it. Thanks for the comments.
posted by sjvilla79 at 8:21 PM on November 16, 2006