Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register
  • We just completed a significant update, but we still have some fixes and adjustments to make, so please bear with us for the time being. Cheers!

Calculating Charging Cost at Home

SageBrush

REJECT Fascism
May 7, 2015
12,084
14,993
New Mexico
Question: I have read that when using a supercharger you are charged through your Tesla app
The credit card you have on file with Tesla is charged
Does Tesla use my checking account from where they got my check for the car's down payment?
No
I see nowhere to input and apply a credit card.
Login to your Tesla account through the Tesla website. Add a credit card account if not already done, or you will not be allowed to supercharge in the future.
 

Pstreicher1

Member
Dec 9, 2020
14
2
Tampa, Florida
Thank you for this information. I do remember now that I bought the wall connector via the web using my credit card.

I was charged $7.80 for my first Supercharging at the WaWa.
 

Needsdecaf

Member
Dec 16, 2018
847
882
The Woodlands, TX
Sagebrush, I'm still trying to wrap my head around all of this.
I regularly see the charging rate at around 38-39 miles per hour with the 240v and 47a wall connection.
So, to figure this I divide the 165 miles needed to full charge by let's just say 38, which gives .42, rounded off.
That's 4 hours 20 minutes, which I believe is what the display settled down at after a bit before I walked away.
Using your formula above I would then calculate 4.2 * .24 = 18.8 kwh total kw used. Correct?
Then using my power company charge of $.0802*18.8 = $1.44 to complete the charge of 165 miles.
That doesn't seem right looking at that amount but if correct, wow!

You're overcomplicating this. The analogy of what you're trying to do is calculating the cost of filling up a tank of gas by using the flow rate of the gasoline nozzle, and time it takes to fill. Too complicated!

Your "tank" is the battery. It's capacity is 100 kWh. This is the same unit that your electric meter reads in, and is how you're charged. To go from 0 battery to full battery is 100 times your per kWh rate "all in" as others have said.

For partial battery charges, which are most, you can figure this a few ways. The easiest is with TeslaFi or another service. It will give you data on each charge, which you can either manually calculate the cost or enter your cost of electricity (per kWh) into the program and it will tell you.

If you don't want to do that, then there are a few other options. First, use the trip meter to display the "since last charge" info. That will tell you how many kWh you used since you last charged your battery. Each time you go to charge, write that number down. Then whatever you're paying for electricity, multiply that to get your total cost. Keep track of that each charge. You'll probably want to multiply it by 105% since there is some loss between the wall and your battery when charging.

You can also do some real rough back of the napkin math. Since your battery capacity is 100 kWh, you can think of each percentage of charge equal to 1 kWh. Record the starting and completing percentage of each charge and then that's your number of kWh. Multiply that by your cost. Again, figure an additional 5% loss so multiply by 105%.

You're not charging to 100% are you....???
 
Last edited:
  • Like
Reactions: lardog

Pstreicher1

Member
Dec 9, 2020
14
2
Tampa, Florida
[QUOTE="Needsdecaf, post: 5278440, member: 92767"

If you don't want to do that, then there are a few other options. First, use the trip meter to display the "since last charge" info. That will tell you how many kWh you used since you last charged your battery. Each time you go to charge, write that number down. Then whatever you're paying for electricity, multiply that to get your total cost. Keep track of that each charge. You'll probably want to multiply it by 105% since there is some loss between the wall and your battery when charging.

You're not charging to 100% are you....???[/QUOTE]

No, I am not. I read in the manual or somewhere that only to charge to 100% when planning a long trip. As I rarely make long trips by car anymore. I keep having this 60% number in my head, to keep topped up and not let it go lower than that before charging. This is not always possible when doing a lot of dailing driving sometimes. The manual states to plug in when not using so I am now charging every night unless only going down the block for something and back. I have got this thing in my head that I need to treat this battery like my cell phone battery. Keep plugged in when near the charger and keep topped up. I like to make things last so I hope I am doing this right.

I have been using the 'since last charged' numbers to give me some idea now. I did look at the TeslaFi website but didn't download the app. I guess I should give it a try at least. I did order the volt/amp/energy meter on eBay yesterday so that should be fun to use too.
 

Needsdecaf

Member
Dec 16, 2018
847
882
The Woodlands, TX
No, I am not. I read in the manual or somewhere that only to charge to 100% when planning a long trip. As I rarely make long trips by car anymore. I keep having this 60% number in my head, to keep topped up and not let it go lower than that before charging. This is not always possible when doing a lot of dailing driving sometimes. The manual states to plug in when not using so I am now charging every night unless only going down the block for something and back. I have got this thing in my head that I need to treat this battery like my cell phone battery. Keep plugged in when near the charger and keep topped up. I like to make things last so I hope I am doing this right.

I have been using the 'since last charged' numbers to give me some idea now. I did look at the TeslaFi website but didn't download the app. I guess I should give it a try at least. I did order the volt/amp/energy meter on eBay yesterday so that should be fun to use too.

Good glad to hear.

TeslaFi does not have an app. It's just the website. If you'd like a referral code, PM me. I believe it gets you a free trial and gets me a discounted month or a free month or something like that.

Sounds like you are starting to figure it out. It can be daunting. I'm an engineer but Circuits was my weakest subject, lol. Luckily I had a EV veteran friend who walked me through the whole thing and now it's easy peasy. Don't be afraid to keep asking for help if you need it, that's what we're here for!
 

Pstreicher1

Member
Dec 9, 2020
14
2
Tampa, Florida
Good glad to hear.

TeslaFi does not have an app. It's just the website. If you'd like a referral code, PM me. I believe it gets you a free trial and gets me a discounted month or a free month or something like that.

Sounds like you are starting to figure it out. It can be daunting. I'm an engineer but Circuits was my weakest subject, lol. Luckily I had a EV veteran friend who walked me through the whole thing and now it's easy peasy. Don't be afraid to keep asking for help if you need it, that's what we're here for!

TeslaFi next but I just tried uploading a picture for my profile and for some reason this system will not take an edited file. I have cropped all that parking lot and some off the top but this system doesn't like the edited pic for some reason. It is over the minimum pixels requirement. The only thing I notice different a second ago was the original is a .jpeg and the edited one shows as a .jpg. I then went into Paint and saved it as a .jpeg but the system here still doesn't like it. Maybe I'll just leave it as it is but I don't want to take up so much space. I notice everyone else here has a nice smaller square pic.

Oh, wait. After I saved this message I see the previous post has the edited pic. I am confused now. I will try to set it back as the edited one and see what happens.

Edit: I must have clicked the back button after setting the edited pic and didn't see the change. It is now displaying the correct and edited one. Whew! I have long days like this a lot. Now to go get my driver's license renewed today. Since covid I was late to set an appointment at the DMV and have been driving on an expired license.
 

Pstreicher1

Member
Dec 9, 2020
14
2
Tampa, Florida
Update! I have installed the eBay power energy meter that
If you really want to know, i would get a meter for about $15 on eBay. I have installed 3 to track car and HVAC usage and they have worked well for me. 100A AC LCD Panel Digital Power Watt Meter Monitor Voltage KWh Voltmeter Ammeter | eBay

I did buy this power energy meter and hooked it up in no time at all. I have logged two charging sessions with it and it appears to be very accurate to what TeslaFi reports. I am very happy you recommended this little item. Many thanks!!!

Power Energy Meter.jpg
 
  • Like
Reactions: dhrivnak

Pstreicher1

Member
Dec 9, 2020
14
2
Tampa, Florida
Good glad to hear.

TeslaFi does not have an app. It's just the website. If you'd like a referral code, PM me. I believe it gets you a free trial and gets me a discounted month or a free month or something like that.

Sounds like you are starting to figure it out. It can be daunting. I'm an engineer but Circuits was my weakest subject, lol. Luckily I had a EV veteran friend who walked me through the whole thing and now it's easy peasy. Don't be afraid to keep asking for help if you need it, that's what we're here for!

I'm liking the TeslaFi website now. Give me your referral code as my trial is going to expire in a few days and I want to give you a free month's credit for all your great info you've given me. You guys here are the best in helping us newbies get going and up to speed. Thx!
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top