Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Cost to charge up?

MarsOrBust

Member
Sep 25, 2020
458
287
Kepler-22b
Trying to figure out the cost to charge up, I know my price per kWh but not sure how many kWh equals each battery percentage. Suppose I want to for from 50% to 80%, how do I determine how many kWh that takes?

or am I going abut figuring this thing incorrectly.
Thanks
 

Sophias_dad

Supporting Member
Jul 29, 2018
1,045
950
Massachusetts
Trying to figure out the cost to charge up, I know my price per kWh but not sure how many kWh equals each battery percentage. Suppose I want to for from 50% to 80%, how do I determine how many kWh that takes?

or am I going abut figuring this thing incorrectly.
Thanks

Assuming a long-range model, 100% is in the neighborhood of 75kwh, or maybe 80 on some new 3's. 30% of that(from 50-80%) is 22.5kwh. Add a little for charging inefficiency and keeping the car awake and battery heated during the charging session, and there you go. Don't underestimate the battery-heating portion, as it gets pretty significant on a low-power circuit.
 

MarsOrBust

Member
Sep 25, 2020
458
287
Kepler-22b
I have an 82 kWh battery so 30% would be 24.6 kWh.
Multiply that by my price per kWh of $0.1217452 = $2.99

I know that does not consider the charge for keeping the car awake and battery heating but not sure how to account for that.
 

camalaio

Active Member
May 28, 2019
1,483
2,087
Vernon, BC, Canada
@MarsOrBust in addition to the above link I'm happy to do and explain the math for you given the following details:
  • Average summer high/low temps
  • Average winter high/low temps
  • Whether your car will be parked outside or not
  • If parked inside, a sense of how insulated it is
  • Details of your charging setup (voltage and amperage)
  • A general sense of how you use the car (e.g. if primarily to/from work, how long that commute is)
I have an 82 kWh battery so 30% would be 24.6 kWh.
Multiply that by my price per kWh of $0.1217452 = $2.99

I know that does not consider the charge for keeping the car awake and battery heating but not sure how to account for that.

I'm behind on newer information, but if you have one of the new "82kWh" packs, I assume not all of that 82kWh is usable much like the older packs and probably the bottom 4.5% is locked out, just FYI (that is, when the display shows 0%, technically 4.5% of that 82kWh resides beneath 0% and isn't to be counted for daily use).
 
  • Like
Reactions: Gasaraki

jaqueh

Member
Dec 2, 2020
72
36
San Francisco
I have an 82 kWh battery so 30% would be 24.6 kWh.
Multiply that by my price per kWh of $0.1217452 = $2.99

I know that does not consider the charge for keeping the car awake and battery heating but not sure how to account for that.
I have a 2021 LR AWD and don't believe I have the 82 kWh batter, how do you know yours is 82 kWh?
 

Rocky_H

Well-Known Member
Feb 19, 2015
6,113
7,107
Boise, ID
Figure about 3.5 miles per kWh. So if you drive 70 miles, 20 kWh. Multiply by your kWh cost.
Really this is about the easiest way to give people an idea of it if you're looking for the ballpark concept, rather than fine tuned monthly billing kind of thing. With the older Model S, being bigger and less efficient, that was really close to about 3 miles per kWh. With the Model 3/Y, that is probably more like 3.5.
So you can run through that with people like "Let's say you do 15,000 miles per year. Divide by 3 miles per kWh, and that's 5,000 kWh times your energy cost per = _____."
 

Rottenapplr

Member
Apr 6, 2019
992
478
LOS ANGELES
I have a dedicated EVSE meter on mine with a digital screen that calculates kwh. I know that doesn't answer you question but being in a household where we share utilities it helps me account for my massive electricity cost.
 

Rottenapplr

Member
Apr 6, 2019
992
478
LOS ANGELES
Opps reread my post and im exaggerating lol We have solar so really our electricity cost are low given we don't hold back on using the AC.

Monthy cost depends on how much I drive really. When I was working and commuting 3x a week 90 miles each way plus 150 miles on weekends it was about $46/month. I have a hybrid that I drive those other days.

If you add 1-2 road trips I remember paying $60-70.
 

Gasaraki

Active Member
Oct 21, 2019
1,525
1,009
Syracuse, NY
I have an 82 kWh battery so 30% would be 24.6 kWh.
Multiply that by my price per kWh of $0.1217452 = $2.99

I know that does not consider the charge for keeping the car awake and battery heating but not sure how to account for that.

The full 82KWh is not accessible. Don't use 82KWh to calculate. The 82KWh battery has around 77KWh that actually used.
 

Gasaraki

Active Member
Oct 21, 2019
1,525
1,009
Syracuse, NY
I have an 82 kWh battery so 30% would be 24.6 kWh.
Multiply that by my price per kWh of $0.1217452 = $2.99

I know that does not consider the charge for keeping the car awake and battery heating but not sure how to account for that.

Doesn't really matter, that's peanuts in the big scheme of things.

That math is close to what I spend a day also. I calculated around $3.00 to $3.50 for every 30% usage. I basically save a little more than half from using gas.

Yes, the following tool is not perfect, bla, bla ,bla but it will give you a general idea.

https://teslanomics.co/tesla-monthly-charging-cost-calculator/
 
Last edited:

camalaio

Active Member
May 28, 2019
1,483
2,087
Vernon, BC, Canada
Doesn't really matter, that's peanuts in the big scheme of things.

That math is close to what I spend a day also. I calculated around $3.00 to $3.50 for every 30% usage. I basically save a little more than half from using gas.

Yes, the following tool is not perfect, bla, bla ,bla but it will give you a general idea.

https://teslanomics.co/tesla-monthly-charging-cost-calculator/
Car standby and battery heating are absolutely not peanuts in the grand scheme, especially for short commuters. But that's why I needed to know if OP lives somewhere cold-ish and such.

Having a short commute while living someplace with a "cold" winter can easily double energy usage compared to expectations (like if you simply figured "75kWh battery goes 500km says Tesla" and did the math for your usage per year). The battery heating feature is no joke and uses a ton of energy. But even without that, standby usage can be quite a bit more than expected as well.

Best case scenario is living somewhere warm and having a long commute. Since a huge number of Tesla owners are in California where both of those tend to be true to my understanding, there's a big skew on consensus vs. reality. But perhaps OP lives there too and does long commutes, then these simpler calculations are probably accurate enough :)
 
  • Love
Reactions: Rocky_H

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