We are all computer novices in life. Sometimes the computer is too old and we want to reinstall it. Set up the CD-ROM drive to start, but cannot set up Bios. We even disassembled the computer and removed all the components inside, including the hard drive, optical drive, graphics card, CPU, and looked at the front and back of the motherboard, but we still couldn't find the bios battery. In fact, although the BIOS batteries used in different brands of laptops are different, and the battery packaging is also different, the technical content of replacing the BIOS battery is not high. Now I will introduce the method to solve your doubts.

1. Understand the BIOS battery

Laptops are generally equipped with two batteries. One is the familiar main battery, which can be used in places where there is no AC power. The laptop continues to work; the second battery is the BIOS battery. The function of this battery is to continuously supply power to some circuits of the motherboard after the laptop is powered off to maintain the system time and allow the changed BIOS settings to continue to take effect.

In many laptops, the BIOS battery model is CR2032, which is silver-white in appearance and only larger than an ordinary button (so this type of battery is commonly known as "button battery"). This type of battery is a rechargeable lithium battery with a rated voltage of 3V (when the battery is new, use a multimeter to measure the voltage between 3.2~3.4V).

2. DIY replacement practice

Tool preparation: a 35W electric soldering iron, rosin, some solder bars, blades, insulating tape, tweezers, screwdrivers, etc. ( Figure 2). ​

Step1: Remove the keyboard and wrist rest. First remove the battery from the fuselage, then refer to the screw icon label on the bottom of the T40, use a screwdriver to unscrew the four No. 3 screws, and then unplug the cable connecting the keyboard and the motherboard from the motherboard socket. Press down the keyboard. Then remove 4 No. 1 screws, 1 No. 2 screw and 3 No. 4 screws, and remove the wrist rest.

Step2: Remove the BIOS battery. The BIOS battery of the T40 is between the optical drive bracket and the wireless network card. The battery has a yellow cover, making it easier to identify. Use tweezers to unplug the battery lead plug from the motherboard socket and remove the battery. ​

Step3: Take out the "heart" of the BIOS battery. Use a razor blade to cut the yellow outer cover of the battery, and then use a soldering iron to solder the two red and black leads from the battery (the red wire is connected to the positive terminal of the battery, and the black wire is connected to the negative terminal of the battery). Use a digital multimeter to measure and find that the battery voltage is less than 2V.

Step4: Solder the BIOS battery. This step is the most critical step in replacing the laptop BIOS battery under amateur conditions. Under amateur conditions, replacing the BIOS can generally only be done with the help of a soldering iron. The outer skin of the BIOS battery has a chromium plating layer, making it difficult to get solder. We can first use a blade to scratch the part of the battery that needs to be welded, then apply rosin on it, and then use a soldering iron dipped in solder to weld. Generally, the welding can be successful. It should be noted that when welding, the contact time between the soldering iron and the battery should not be too long, and the welding time at one time should generally not exceed 3 seconds, otherwise the new battery will be damaged or the performance of the new battery will be reduced. Also, the positive and negative terminals of the battery must not be connected incorrectly. Generally speaking, the side with the battery logo (such as battery brand, voltage, etc.) is the positive electrode, connected to the red lead, while the other side is the negative electrode of the battery, connected to the black lead.

Where is the laptop bios battery? How to replace it? In fact, it is not difficult at all, 4 majorThe steps will teach you how to replace the BIOS battery. Of course, first you must clearly understand what a BIOS battery is and what it looks like. Then you must have a set of all-round essential tools. Then follow the steps introduced by the editor step by step. The editor reminds everyone that a 5W soldering iron, rosin, some solder bars, blades, insulating tape, tweezers, and screwdrivers are all essential tools.