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Charge kWh usage calculator/tracker

Posted: Tue Jan 25, 2022 9:20 am
by LilSparky
I am using the Nissan EVSE at 110v on an outdoor plug in a shared use space where I live. The owner of the property is not currently interested in installing a L2 EVSE but is okay with me using the 110 plug so long as I track my usage and reimburse. I can't use the kill-a-watt meter outdoors so that's not really an option.

I have a solution that mostly works, but I would like to see if there is a better one out there. Currently, I am using a web-app and a google form/script to start and stop a timer that calculates duration (similar to a employee clock-in/clock-out system.) I plug in, access the web-app to start the timer and then stop it when I am done and it calculates based on the time, assuming 1.3 Kw per hour. At the end of the month, I send a screenshot of my usage and they add it to my electric bill.

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This is great unless it reaches full charge at 3AM at which point I have to go back and change the end time based on when the NissanConnect app sent me a notification that it was done charging (if it does actually notify me.) Yes, I have thought of just not plugging it in if it would charge all the way to 100%, but sometimes my schedule just doesn't work out like that.

Does anyone know of a better way to track usage? I was thinking of trying to use the NissanConnect API to do the datalogging for me, but it is a bit over my head.

Re: Charge kWh usage calculator/tracker

Posted: Tue Jan 25, 2022 9:51 am
by alozzy
If you already have a kill a watt meter, why not just stick it inside of a waterproof extension cord box?

Do an Amazon search for:

waterproof extension cord box

Many choices...

Re: Charge kWh usage calculator/tracker

Posted: Tue Jan 25, 2022 10:43 am
by LilSparky
alozzy wrote: Tue Jan 25, 2022 9:51 am Many choices...
At your recommendation, I was perusing the Amazon looking for something that might work for my application and I came across a few WiFi Plugs w/Energy Monitoring... which might be exactly what I am looking for. I am a little worried about keeping something plugged in pulling max(ish) continuous load. I've seen more than a few melted Kill-a-Watt meters.

Re: Charge kWh usage calculator/tracker

Posted: Tue Jan 25, 2022 1:33 pm
by LeftieBiker
All that you really need to do is measure say, 30 minutes of charging with the Killowatt. Then it's simple multiplication. If you want the most accurate estimate, then do the first half hour, a middle half hour, and then the last 30-60 minutes, when the car is EQing the battery.

Re: Charge kWh usage calculator/tracker

Posted: Tue Jan 25, 2022 2:34 pm
by LilSparky
LeftieBiker wrote: Tue Jan 25, 2022 1:33 pm All that you really need to do is measure say, 30 minutes of charging with the Killowatt. Then it's simple multiplication. If you want the most accurate estimate, then do the first half hour, a middle half hour, and then the last 30-60 minutes, when the car is EQing the battery.
Yes, I already used the Kill-a-Watt to find that the Nissan EVSE pulls 11.86 amps for the entirety of the charge. At 110v that is 1.3 kilowatts per hour. I have a timer and can use it, I am just looking for a more automated way to measure and log actual kWh used so that I don't have to start and end my timer each time I plug in/unplug.

In researching some of the smart plugs out there, it looks like many of them can track actual usage, so I will give that a shot.

Re: Charge kWh usage calculator/tracker

Posted: Tue Jan 25, 2022 3:42 pm
by alozzy
Another option is an outdoor rated smart plug, many of which log kWh usage and work via an app.

Re: Charge kWh usage calculator/tracker

Posted: Tue Jan 25, 2022 6:04 pm
by LilSparky
alozzy wrote: Tue Jan 25, 2022 3:42 pm Another option is an outdoor rated smart plug, many of which log kWh usage and work via an app.
This is the answer!

I purchased a couple different ones to see which will work the best for my application.
Thanks.

Re: Charge kWh usage calculator/tracker

Posted: Tue Jan 25, 2022 10:49 pm
by alozzy
LilSparky wrote: Tue Jan 25, 2022 6:04 pm
alozzy wrote: Tue Jan 25, 2022 3:42 pm Another option is an outdoor rated smart plug, many of which log kWh usage and work via an app.
This is the answer!

I purchased a couple different ones to see which will work the best for my application.
Thanks.
No worries :-)

Post back and share with the forum users how well the smart plug works for this application, I'm sure others in future will have to accurately track the electricity consumed by EV charging in a rental/condo/townhouse charging use case...

Re: Charge kWh usage calculator/tracker

Posted: Mon Jan 31, 2022 3:12 pm
by LilSparky
alozzy wrote: Tue Jan 25, 2022 10:49 pm
Post back and share with the forum users how well the smart plug works for this application, I'm sure others in future will have to accurately track the electricity consumed by EV charging in a rental/condo/townhouse charging use case...
This one off Amazon has done the best: https://www.amazon.com/gp/product/B08H1 ... UTF8&psc=1
It doesn't have the ability to export a CSV file, but the "Smart Life" app does show the kWh usage by day, month, and year. It was also accurate to within 0.5% of what my Kill-a-Watt shows over a couple long charging sessions (they are all long sessions when you are using 110v.)

Something to keep in mind if you go this route is that not all "Outdoor Smart Plugs" have energy monitoring capability so whatever you purchase, make sure it can actually log the data in it's app. Also, I am using a 3ft, 12 gauge, heavy duty extension cable between the EVSE and the smart plug because my outlet is 3ft off the ground and hanging or mounting the EVSE isn't an option.

We will see how my system holds up over time.

Re: Charge kWh usage calculator/tracker

Posted: Tue Feb 01, 2022 12:19 am
by alozzy
Thanks for posting back with your experience so far with the smart plug solution. I'm sure someone in future will find this very helpful.