I just updated my Zorin OS into the 17.2 core and now my laptop will always shuts down at 39 percent and when charge, it will only reaches up to 79 percent and no longer 100. I was thinking that it might be a software error (since before I update, my laptop will suddenly like to connect and disconnect randomly and only in my home wifi but after updating, the error is gone) but it also starting to sound more to a hardware error(it's an old laptop already anyways). can anyone help?