I just shift from Windows OS to Ubuntu 18.04 and my LENOVO ideapad 310 is experiencing random shut down when it is unplugged from AC charger. Battery sometimes is at 80%, sometimes at 20%. Laptop is quite new and it didn't react like this when I was using Windows. Battery and fan seems working properly. Shut downs never occur when laptop is plugged.
I haven't find a solution in the web.
Thanks for your support