How to replace the CMOS battery? Do I need to order a special battery?

Hi @cassarno

Looking at the coin cell battery replacement procedure in the service manual (scroll to p.39) the CMOS battery, which is insulated, unlike a standard coin cell battery, has wires attached to it which unplug from a connector on the motherboard so a standard coin cell battery won’t be able to connect to the motherboard the same way. It is not inserted into a standard coin cell battery connector.

The part number for the battery is 23.21212.091.

Here’s a link to just one supplier. It is shown only to give you an idea of the cost of the part and to show what it looks like.

There are other suppliers online that may suit you better. Just search online using the part number only in the search box of your browser to get results for suppliers of the part. (it is also the same part number for a lot of Dell Inspiron 11 3000 series laptops)