Laptop CMOS Battery

[deerslayer]

How difficult is it to change the CMOS battery in a laptop? I have a laptop here that keeps losing it's bios settings, so i'm assuming it's the CMOS battery.

The laptop is a Dell Inspiron 3700.

 

[brandonl]

Well on two laptops I have messed with, it meant either unscrewing 10 or so screws and taking off a few pieces to going all out with 10 o so screws and taking everything on top off. My newer one I could't even find a CMOS battery.

 

[deerslayer]

Is it possible the BIOS info is saved using the laptop's battery rather than a CMOS battery? I could not find one.....

 

[brandonl]

Nope ... otherwise BIOS would go out all the time. Your best bet is to e-mail manufacturer.

 

[jschuk]

Not many laptops use batteries like the desktops do. Some use batteries that are only connected to the board by a wire and the battery sits in a compartment or is taped down somewhere. Others (Compal units) are soldered down to the board. Those look like buttons (like a shirt or pants button), usually brown in color. Try turning on the laptop and letting it run solid for 24 hours. It can sit idle, but make sure it stays on.

 

[deerslayer]

Hmm....now that the laptop battery has gotten a full charge, it is keeping the BIOS settings.

There wasn't much to the internals of the laptop! I've never actually opened one up until now. The owner of the laptop always had it plugged in, and I assumed the BIOS settings were saved from the laptop battery because once the battery stopped charging, it kept losing the settings.

I guess i'll have to look again!

 

[Paperlantern]

well yes, if the laptops cmos battery is dead, the unit will require a solid flow of power form some source to keep the settings. so concequently, if the main battery dies, then the cmos settings will fly the coop as well. Batteries on dells are almost always a green or black set of button batteries (usually 7.2 or 7.5 volts) plugged into the board and taped down or held in place in a separate compartment as somone mentioned. and yes, if the computer is losing cmos every so often, but your not using it for long periods of time, leave it on for a good long while, like someone said, 24 hours, without it going to any suspend or any power saving mode, jsut let it stay on, sometimes that can rejuvenate the cmos battery just enough so it will hold power to the settings in between regular usages