Do I need to log the hours I use my personal computer and cell phone for my business?

For my business tax return, I'd like to deduct some of the costs of my new PC based on the percent I use it for my business vs. personal.  I've read that I can do this and I just need to enter the percentage I use it for my business into turbo tax.  However, do I need to somehow document how much I use it for business in case I'm audited?  If so, how would someone do this?  Do you really need to log how many hours you use it for personal vs. business?  If so, I feel I'll spend more money in time spent logging hours than I'd save writing it off.   Thanks for the input.

 

I also have the same question for my cell phone.

 

BTW - I did find this article that said "Effective 2018, there are no recordkeeping requirements for any business use of computers." Meanwhile, I've read many things that say I do need to keep records for my cell phone.  So looking for some supporting input to what the real answer is.  

 

Thanks for the help!