Today, laptops with non-removable batteries are becoming more and more common due to a pressure to make laptops lighterweight and thinner.
Historically, computers have had a CMOS battery to operate the real-time clock and perhaps retain BIOS settings. I know that most laptops with removable battery still have the CMOS battery because they do not lose clock settings when temporarily taking out the removable battery.
However, modern non-removable battery laptops could in theory remove completely the additional CMOS battery. Is this done in these cases?
Best Answer
The chances are big that pc's and laptops (even those with non-removable batteries) will still have a CMOS battery.
The reason is for the technology of the removable battery. They're rechargeable batteries, and its in the nature of a rechargeable battery that it will slowly run out of battery, regardless of it being used. A CMOS battery however, does not.
It would be very weird, if your device is not being used for a month and its non-removable battery runs out, the BIOS would lose its settings.
One could argue that nowadays you have flash medium that you can write to that do not need to be powered in order for their memory to be retained, but the downside to those is that their state deteriorates with each read and write, and believe it or not, a BIOS is still being read and write a lot to.
Technology does change, and they may find new ways to more efficiently store power in rechargeable batteries that will retain their power for much longer or find a way to have a BIOS using flash memory in such way that it will not matter on wear that this changes in the future, but I don't see that happening anytime soon. The use of a CMOS battery is not something that costs a lot of money, so the gain to use different approaches would likely cost more.