Ne meither and Asus didn’t know, either. IDK, my laptop wouldn’t hold BIOS settings or Time/Date. Asus told me it was a coin style CMOS battery on the back side of the motherboard. Called them back to report not finding it and then they refused to help because they accused me of intent to modify the unit, which they do not support. They suggested I send it to a service center on the east coast (I’m on the left coast) with an open limit on repair. All this for a laptop which has been out of warranty for 3 years. Eventually one tech suggested it might be built into the main battery but couldn’t say for sure.

Next time I will buy a Dell, Acer, HP or some other brand.