Kill a Watt EZ

It’s fine.

 

Yap, it works fine to monitor the kWh use at the wall. It is rated to max 15A, which works fine for 12A max of the L1 EVSE. I've had it on the wall for almost two years now for daily monitoring of kWh used for charging my PRIME. Just stick with the authentic P3 International product. Power Monitor - Kill A Watt EZ | P3 There are other cheaper knock-off kWh meters out there, but many of them do not have 15A max spec.

 

Just curious, why?

 

I don't know about OP, but I do it so I have a very clear idea of how much I am spending on fuel (in this case electricity). With gas, you know the exact amount you spend for each fill, but with electricity, it is not that easy unless you have an expensive L2 EVSE that records amount of electricity used for each charge session.

 

Compare the last/pre-EV year bill, the difference is your monthly consumption, give or take couple of bux. Or just use car's displayed monthly mileage * miles. The Prime's battery is so small, even with 2-3 full recharges each day it's not that much anyway.

 

If you are not worried about a few bucks you spend everyday, then you would not monitor it using Kill-a-watt meter. For me, energy cost spending, or for that matter any spending down to a penny, is a very important to know. That's all.

FYI, our monthly electric bill fluctuate enough, comparing to different period will not give me even an estimate for the electricity used for charging my car. The car's displayed monthly mileage have no information on how much of that mileage was driven by EV mode using electricity provided from the grid. Furthermore, our electricity rate is very high as to driving EV on PRIME is often more expensive than using gas. If I did 2-3 full recharges each day, which I do not do currently, would end up costing me ~$119/month give or take couple of $.

 

I hear you, I just don't get the importance of knowing if your Prime consumed 198 or 202 KWh last month. What are you going to do with this info?

And I've meant comparing same month bills from different years.

 

If you ever used personal financial management application, like Quicken, you will know what to do with the info. I like to know where my hard earned money are going. I also keep track of every single penny used for my car, including a few bucks I spent on washer fluid and 4 quarters I used for rinsing my car at self car wash. In the end when I am done with the car, I have TRUE cost to own a car. I did that for my last 3 cars so far. Furthermore, the information I have gathered so far is invaluable in planning solar panel on our roof, which I am planning to install sometime this year.

Also comparing same month bills from different years are no help in estimating use of electricity for charging, at least not in our household. Year to year fluctuation of the same month with or without charging is too large.

 

The Kill-A-Watt can actually go beyond 15A for a short time (just like a 15A circuit can). I hooked it up to my 15A rated miter saw to see what would happen, and it showed a little over 17A while cutting through some particularly dense wood. The display flashes if the amperage exceeds 15. Obviously it's not rated for over 15A continuously, and it could get too hot if you try.

 

How many kwh is a single full charge?

SM-N960W ?

 

It's like asking how much milk is in 1 gal jug.

 

With L1 (120V) EVSE that comes with the car, at the wall readings have been 6.4-6.8 kWh from EV range remaining zero to full charge. I use 6.6 kWh on average. However, many Prime owners who use L2 (240V) EVSE have reported here their reading for a full charge is 6.1-6.3 kWh. I attribute the differences of ~10% is due to the efficiency difference between L1 and L2 EVSE.

 

Thanks Salamander. By the way, from your user name, can I deduce that you are an amphibian/reptile enthusiast?

My electricity cost is 6.8 cents per kwh. And a full battery charge runs for 2 days for me. So my monthly cost is $6.73. Previously I used to spend $40 on gas. Now thats something!

SM-N960W ?

 

Oh, here is the kicker! My household electricity cost by kwh consumed comes to $61.56. But then all the additions i.e. access charge, local fee, taxes etc. bring the amount up to $151.

SM-N960W ?

 

I think it is a fictitious character in PlayStation game. I never played it, but when I was creating my account here my son was playing on our large screen TV and he told me about it. I used it as a handle, and it got stuck here.

Do you mean a full charge will last you for 2 days to drive around? Meaning you drive less than 12 miles/day? I usually drive ~40miles a day. Which meant previously I had to put gas every 10 days. Now with ~25-35miles of EV, I need to stop for gas only once a month or longer.

Yeah, I have seen those bogus billing statements others have posted. Even if the official rate is 6.8 cents per kwh, if you have to pay for all the other "fees", then your true electricity rate is whatever the total monthly payment you make divided by the total kWh you used for that month, IMHO. Mine comes up to be ~$0.2/kWh.

 

Yeah, I drive less than 15 miles a day on average. I agree with your assessment of overall electricity costs. Have not calculated that in my case yet.

SM-N960W ?

 

OK. My household electricity cost (including bogus charges comes to 15.1 cents per kwh.

SM-N960W ?

 

I got my kill-a-watt in the mail a couple days ago. My R/T to work is ~25mi and I usually have ~5mi to spare on the display. It takes me about 5.6-6kW to "fill up". At $0.11/kWh my costs are roughly $14/month. A couple bucks more if you include weekend use.