No, the data will not go to zero until you reset the plug.It will add up and count the average data of today, past 7 days and past 30 days.

Thanks for the reply Anton.
Your answer seems pretty clear but what I need is the total usage (my PHEV is plugged into it).

I guess if it is always a 30 day average I will have to reset the device every 30 days so I can see the actual total for the month. I will have to figure out how to reset the device to zero.

The only way is to reset the device to factory defaults....
Not easy to reach your requirement.

Yeah, Kevin, I see that the reset process is a pain. I guess I could make a product feature request of being able to reset the totals to zero.

I guess I'm back to using my Kill A Watt 4460.

You could use AutomationManager running as an AutomationServer (click on my signature here for the intro). It will log HS110 power to your google drive account as a spreadsheet which could then use to analyse in any way you'd like, including using formulas.

Hi Mike,

I read quite a bit of your information on the Automation Manager and it is quite interesting and quite a bit over my head. It looks like a heavy duty solution (running a server 24/7) to a simple problem. Thanks for the info tho. :)

Oh, I have an iPhone...

True, it is a bit more complicated but it does snap together quite well and it does come with support. That 24x7 server runs on a $20 low end android phone - in most cases cheaper than the HS110 which also runs and is connected 24x7 to TP Link's cloud. So not as much as a leap as it might seem :). You'd still be using your iphone to control the switch and a web browser to view the spreadsheet - there's very little chance of being tainted by android... If you change your mind you know where to find me :).