What is bios?
BIOS, the Basic Input Output System, built into your PC and is the first software code to run after you switch it on. It’s job is to find all the Input and Output devices such as your keyboard (input) and your monitor (output).
Why does it need a battery?
Modern computers use a non-volatile memory (memory that does not need power) for ordinary bios settings, but to keep track of time a program needs to calculate values and record them in RAM (volatile memory) which requires battery back up.
How can I tell if the battery needs changing?
- You boot your PC and the bios does not load (often you find yourself staring at the monitor manufacturers logo waiting for something more interesting to happen, but it doesn’t).
- Checksum Errors show on the screen on boot up
- Incorrect date and time
How do I change the battery?
You will need to find out which battery your PC uses. Either check the documentation that came with your PC or call the retailer or manufacturer. If you are still in the warranty period then get them to do it.
Once you have the battery type check it by opening the PC. Most modern computers use a lithium CR2032 button battery. PC manufacturers usually find the most inconvenient place for a battery in their designs. They then place power units and cables in front of it and to top up the frustration surround it with some of the most delicate transistors and parts required to run the PC.
You have two choices. Completely dismantle the PC, remove or manoeuvre the motherboard to a convenient position for replacement. Or use a screw-driver with a knob of play-doh or blue-tack on the end of it (blue-tack is better).
Step 1 - Locate the battery and remove it
Note the clip which can just be seen in the above picture at between 1pm and 2pm if the battery was a clock face. To remove the battery gently push the clip with your screw-drive flat-head and the battery will fall out.
Step 2 - Prepare the battery
Now take the new battery and manoeuvre it into place. A light but firm push will create a click. Remove the blue-tack and close the computer.