I've yet to find a laptop mainboard that doesn't work without a battery. As I've written below, I'm getting extremely boring old office laptops with integrated graphics. Usually phones also work fine without a battery. However, I'm not touching phones because I will not fiddle with locked bootloaders and "the Android situation". Running plain Linux is a hard requirement for me.

I'm just looking at an old Dell laptop refusing to boot without manual intervention because it looses its time setting since I removed its main battery. If I can fix that it'll become a very capable server for my home setup. Not sure it'll work though, as the bios can't be configured to ignore the time reset.