I apologize in advance if this has been asked a million times already but I did use the search function and the results were a bit garbled. I just got an MY (first EV) and I'm wondering if there is a very simple way in which Tesla has allowed an owner to easily determine how much electricity per month was directly related to charging the car. I have it set up to only charge after midnight to take advantage of the cheapest rates but does the car or perhaps a third-party app have a way of determining how much was attributable to charging each month?
How to measure power consumption at home?
- Thread starter rossini
- Start date
Puma2020
Member
The non electronic way, is to go out and read your meter each day, roughly at the same time each morning and/or evening.
After a few day, you'll have an fairly good idea of what you are using.
Do this on the day before plugging in your car, then on the day you plug in your car and the day after.
I recommend doing it each month or season. Very interesting to track what you house is pulling from the grid.
It is also useful to figure out what size you need if you ever do solar panels.
PM me if you want more solar panel info. I do not own, operate or am affiliated with any solar company.
I have had solar panels for a few years now and am willing to provide whatever little guidance I can.
After a few day, you'll have an fairly good idea of what you are using.
Do this on the day before plugging in your car, then on the day you plug in your car and the day after.
I recommend doing it each month or season. Very interesting to track what you house is pulling from the grid.
It is also useful to figure out what size you need if you ever do solar panels.
PM me if you want more solar panel info. I do not own, operate or am affiliated with any solar company.
I have had solar panels for a few years now and am willing to provide whatever little guidance I can.
There are some thirds party apps, but they require a monthly fee and giving them your Tesla credentials. ex. Teslafi
One "easy way" is to set a trip counter on the car. That will give you the number of kWh used excluding the time that you spend in the car not driving, and any "overhead" while charging.
One "easy way" is to set a trip counter on the car. That will give you the number of kWh used excluding the time that you spend in the car not driving, and any "overhead" while charging.
I use Chargepoint HomeFlex as my charger at home. It cost me almost nothing for the unit after state and local utility rebate. The Chargepoint app does tell me how much electricity it used per session and by month. It also estimate how much that cost me based on the local utility rate.
Johnny Vector
Member
Unless your home heating is provided by electricity, and you're in heating season. Then the electrical use per day is dominated by that, so it's hard to get a baseline.
If you live in an area where the electric utility has smart meters, they probably have a way for you to see your usage broken down hourly. I can clearly see when my car is charging on the hourly graph.
You could just do the math too. Your car displays the amps and volts it’s drawing while charging. Watts=volts x amps
For example if you’re charging at 48 amps on a 240 circuit:
240v x 48a = 11,520W (or 1.15kW)
If you charged for an hour, you consumed 1.15 kilowatt-hour (the billing unit that your electric utility uses).
For example if you’re charging at 48 amps on a 240 circuit:
240v x 48a = 11,520W (or 1.15kW)
If you charged for an hour, you consumed 1.15 kilowatt-hour (the billing unit that your electric utility uses).
I use a Dryer Buddy to charge my car. It has meter that tells how many cumulative kilowatt-hours have gone through the charger plug.
Or just install your own monitoring system, like adriankumpf/teslamate
I have mine running on AWS Lightsail - $3.50/mo. You can also host for free on google cloud, or at home on a raspberry pi.
Works better than Teslafi, with a much nicer UI too. And credentials don't go to a 3rd party.
pics: Screenshots | TeslaMate
JimBob 909
Little Red Raven
I go to my So Cal Edison site and it shows me daily usage. I get a huge spike on days I charge. I can deduct "daily use" and get a close amount of electric used for charging. Doesn't cost me to use the Edison site. Since it shows my tier rate, I can figure what it cost to charge.
Johnny Vector
Member
Hmmm. "it reads the current one million times each second". That's either wrong or stupid. There's nothing useful to be learned by sampling faster than 240 Hz. I guarantee they didn't put in a 1 MSPS A/D just for fun. Just like I'm not interested in a solar power company whose marketing doesn't know the difference between kW and kWh, I'm not interested in a power monitoring company whose marketing doesn't understand their actual hardware.
I guess they are sampling the current with a 1 MHz ADC because there are device like dimmer and switching power supply that conduct current for fraction of cycles. This is useful at identifying the type of load.
Dimmer - Wikipedia
Dimmer - Wikipedia
Correct me if I’m wrong, but wouldn’t that be 11.5 kW ?
Yep. I was going to mention that or JuiceBox.
OP might still have delivery and bills from PG&E. if so, one can monitor whole house electricity usage via devices like at PG&E Stream My Data (e.g. Rainforest EAGLE gateway).
Well, if you read the website more thoroughly you'd see in the specs the following:
Signal Processing
1MHz Sampling Rate (4M data points per second) 1GHz ARM Processor
There may or may not be a point to it as far as you know, but they implemented it. I suspect it's a byproduct of the architecture they chose and Marketing decided to trumpet it as a selling point.
