Charging question

[vishnumrao]

I just got a MY 3 days ago. There is no 240V outlet in the garage and I have been charging for the last few days from a 120V outlet using a mobile charger (with J1772) that came with my other non-tesla EV. While I do intend to get a 240V outlet in the garage, there in no urgency as my daily usage is ~20 miles which can be easily replenished in 6 hours of 120V charging.

I live in Sacramento and SMUD is our utility. In the non-summer months, we have a 5-8PM peak and then 8PM -5PM next day is non peak. Additionally SMUD gives an EV credit for all charging between 12-6 AM. So technically 12-6 is the lowest rate at which my EVs should charge.

However in the tesla app, there is no easy start & stop charging option. If I choose the "off-peak charge" option, then it asks for a Off-peak End time, but no option to indicate when it should start or stop charging.

in the charge tab, if I enable the Scheduled charging option then it asks for a "start charging at" time, but no stop charging time. I set charging start time to 12 AM and car start chargin. The problem here is that once the Y starts charging at 12 AM, it does not know when to stop. I set up departure at 8 AM. Here the Y continues to charge beyond 6 AM and went on to precondition the battery at 8 AM but kept charging beyond 8 AM as well. This defeats my goal of charging only between 12-6AM.

Any thoughts on how to correctly set up charging?

 

[Silicon Desert]

If you subscribe to TeslaFI, it will do those schedules for you. That's one way.

 

[vishnumrao]

Thank you. I will research it. But I am not very keen on signing up for yet another subscription & payment.

 

[Silicon Desert]

Thank you. I will research it. But I am not very keen on signing up for yet another subscription & payment.

I understand. It's $50 a year. We really like the many features, but sure, I understand folks that hate subscriptions. For the most part I do as well.

 

[RTPEV]

Yeah, with the scheduled start and scheduled departure timer functions, you have to pick one or the other. Usually it's not a problem, but if you're only at 120V and it's taking >6 hours, you're kind of stuck.

I was going to recommend TeslaFi as well. I understand you are hesitant due to the cost. Understand that it really offers a LOT of functionality for that money (that may or may not be important to you). Even if there are no other features that interest you, is it possible that you'd wind up saving >$50/year by using it versus not using it?

I'm not aware of other apps that might offer similar functionality, but that's only because I pretty much stopped at TeslaFi. But perhaps you should look around and see if there are other apps that might give you similar functionality for free (or less $$). There used to be a Google Home app that you could probably attach to a timer, but as far as I know Google broke it and it hasn't been fixed. There may be an Alexa skill. Well, since are you plugged into a 120V outlet, maybe you can get a smart outlet or some other device that has a timer on it (although I'd be cautious about whether it can handle the large continuous current).

You are kind of pushing the limits with your requirements here. Something may have to give.

 

[MY1stEV]

Thank you. I will research it. But I am not very keen on signing up for yet another subscription & payment.

I will say, my only regret about subscribing to Teslafi was that I didn't do it from day-1 of getting my car.

If you'd like to try it, when I signed up the promo code "FREE30" extended the trial period to 30 days. Also, you do not have to provide any payment info up front. Near the end to the trial period you will get an email alerting you if you don't add a credit card to your account then your enrollment will terminate.

 

[ScoobyDoo82]

I will say, my only regret about subscribing to Teslafi was that I didn't do it from day-1 of getting my car.

If you'd like to try it, when I signed up the promo code "FREE30" extended the trial period to 30 days. Also, you do not have to provide any payment info up front. Near the end to the trial period you will get an email alerting you if you don't add a credit card to your account then your enrollment will terminate.

TeslaFi is fantastic, I used it for my first year of ownership with my Model Y. I was happy with it for the most part but it began to feel like “yesterday’s product” with its web-only interface and very few features. The web interface doesn’t work very well on smart phones either. I understand that TeslaFi has improved over the years.

I’ve been using Tessie for the past year and it’s the same $50/year. I find the interface to be much better overall and it looks current and is constantly updated by its author. The support has been excellent from him too. I was able to import all of my TeslaFi data as well. This app has the same automation features and even more in depth analysis/charts/graphics for your car. The plus side is that it’s a native iOS app with a very good web interface too, so using it on the phone and laptop has been great.

I’m no TeslaFi hater.. but I suggest folks should try Tessie. I’ve been happier with it.

 

[Earl]

But I am not very keen on signing up for yet another subscription & payment.

Its good to hear I'm not the only one with 'subscription fatigue'. I also don't like giving my Tesla credentials to an unknown 3rd party.

With a 240v charging station, a single charge time during the night should be fine. With 120v, however, it may not provide enough charge for some days' driving.
possible short term solution: spend a bit more on electricity
possible long term solution: install 240 v charging station

 

[E90alex]

There is no way to set start and stop times with Tesla app or in car. This is a glaring hole as many other EVs and PHEVs have this ability, as well as setting different schedules per day of the week instead of just “weekdays” and “all week”.

Your best option will be to set off peak end to 6am and your scheduled departure to whenever you want to depart if you want it to precondition (it will draw some wall power when it does). Otherwise just set departure time to the same as off peak end.

It will calculate backwards as to when it needs to start charging to meet the goal by 6am. So if you only need to recharge approximately 9% or so then it would fit within than 6 hour window, but if you need to charge more then it will start sooner than 12am if it thinks it needs more time.

There’s really no avoiding it unless you get a 240V installed or adjust the charge limit so it doesn’t recharge more than 9-10% per day. Or pay for the third party apps that give you more granular control.

 

[ewoodrick]

It seems as if starting charge after 8PM is your optimal setting. Then you know it should be complete.

The other option of stop charging tends to work better for folks in really cold climates, as the battery will then be warm when ready to leave.

 

[E90alex]

Ok I just looked up your utility and they give 1.5 cents per kWh credit for EV charging. Even if you started at 8pm when off peak starts and charged to 6am so 10 hours, that’s an extra 8.64 cents you lose from not getting the extra EV credit, or $31.54 a year.

Tbh I don’t think that’s enough to worry about in the mean time especially if you’re planning to get a 240v installed which should be more than enough to recharge within the 6 hour window.

 

[Watts_Up]

I am not fanatic to have to pay a subscription to give me information
already provided by the car, such as the Watt hour per mile.

What I am really interested is the monthly amount of electricity that is needed to recharge my car,
which is greater than the battery amount stored in the battery.

I installed a Wattmeter, so I can determine the efficiency of my charger
and determine the exact monthly cost of my electricity bill

So yes, use 240V, even 20A or 30A, because this would be more efficient than charging at 120V.
Converting 240V AC to 400V DC typically is around 85-90% efficient.
Using 120V AC to 400DC you double the losses, around 75-80% efficient.
This is mostly because the longer the charging, the longer the battery might need to be warm up.

Also, if you are a little handy, I would recommend adding a timer switch relay,
so you can charge any time and as long as you want.

For example, I don't need a full charge during the week,
but just before the weekend I want to be sure that my car will be fully charged
so I will not have to worry and have to stop and lose time to charge.

EVs Explained: Charging Losses​

​

How can the charging losses be minimized? Higher-voltage charging equipment is one way. ​

Our long-term 2019 Tesla Model 3 Long Range Dual Motor test car is currently averaging 95 percent efficiency ​

from a Level 2 Tesla 240-volt wall connector. Staffers charging at home using a typical 120-volt wall outlet ​

saw efficiency of, at best, 85 percent, and it dropped to as little as 60 percent in very cold weather, ​

when charging the battery requires expending significant energy to keep it warm.​

​

​

Note: If you are really interested monitoring your electricity consumption,
I would recommend using an Emporia monitor and EV charger.

Emporia Vue: Gen 2 with 16 Sensors

Lower your electric bills! With the Emporia Vue Real Time 24/7 Electricity Monitor for the home. Great for Energy savings, real time utility bills, solar installations and net metering. Includes expansion module for monitoring of individual circuits.

shop.emporiaenergy.com

Emporia EV Charger | NACS (Tesla) or CCS (J1772) | Energy Star | UL Listed | 48 Amp | 24' Cable

Meet the powerful game changer in electric vehicle charging. The Emporia Level 2 electric vehicle charger is consistently voted one of the best EV Chargers on the market. With its 24’ cable and either a CCS / J1772 or NACS / Tesla connector, it can easily reach and charge any EV up to 40 amps...

shop.emporiaenergy.com

 

[vishnumrao]

Ok I just looked up your utility and they give 1.5 cents per kWh credit for EV charging. Even if you started at 8pm when off peak starts and charged to 6am so 10 hours, that’s an extra 8.64 cents you lose from not getting the extra EV credit, or $31.54 a year.

Tbh I don’t think that’s enough to worry about in the mean time especially if you’re planning to get a 240v installed which should be more than enough to recharge within the 6 hour window.

My goal is not the cost savings. Its the attempt to do a constant 6 hour charge every night, rather than go beyond the 6 AM after which we are shuttling the kids to school etc.

Its the simplicity of the charging that I was seeking, not cost savings.

 

[vishnumrao]

I am not fanatic to have to pay a subscription to give me information
already provided by the car, such as the Watt hour per mile.

What I am really interested is the monthly amount of electricity that is needed to recharge my car,
which is greater than the battery amount stored in the battery.

I installed a Wattmeter, so I can determine the efficiency of my charger
and determine the exact monthly cost of my electricity bill

So yes, use 240V, even 20A or 30A, because this would be more efficient than charging at 120V.
Converting 240V AC to 400V DC typically is around 85-90% efficient.
Using 120V AC to 400DC you double the losses, around 75-80% efficient.
This is mostly because the longer the charging, the longer the battery might need to be warm up.

Also, if you are a little handy, I would recommend adding a timer switch relay,
so you can charge any time and as long as you want.

For example, I don't need a full charge during the week,
but just before the weekend I want to be sure that my car will be fully charged
so I will not have to worry and have to stop and lose time to charge.

EVs Explained: Charging Losses​

​

How can the charging losses be minimized? Higher-voltage charging equipment is one way. ​

Our long-term 2019 Tesla Model 3 Long Range Dual Motor test car is currently averaging 95 percent efficiency ​

from a Level 2 Tesla 240-volt wall connector. Staffers charging at home using a typical 120-volt wall outlet ​

saw efficiency of, at best, 85 percent, and it dropped to as little as 60 percent in very cold weather, ​

when charging the battery requires expending significant energy to keep it warm.​

​

​

Note: If you are really interested monitoring your electricity consumption,
I would recommend using an Emporia monitor and EV charger.

Emporia Vue: Gen 2 with 16 Sensors

Lower your electric bills! With the Emporia Vue Real Time 24/7 Electricity Monitor for the home. Great for Energy savings, real time utility bills, solar installations and net metering. Includes expansion module for monitoring of individual circuits.

shop.emporiaenergy.com

Emporia EV Charger | NACS (Tesla) or CCS (J1772) | Energy Star | UL Listed | 48 Amp | 24' Cable

Meet the powerful game changer in electric vehicle charging. The Emporia Level 2 electric vehicle charger is consistently voted one of the best EV Chargers on the market. With its 24’ cable and either a CCS / J1772 or NACS / Tesla connector, it can easily reach and charge any EV up to 40 amps...

shop.emporiaenergy.com

Thank you very much for pointing out that charging at 120V is less efficient than at 240V. I had wondered about that over the weekend as I noticed that the Y has some fans spinning or some like that as makes a small noise as its charging.

Long term I am definitely getting a 240V charger put in. In fact I already bought a NEMA 14-50 charger. I am getting quotes from licensed electricians to install.

 

[vishnumrao]

All, thank you for the inputs. I agree long term getting a 240V charger will solve my problem as I can just start at 12AM and charging to 80% daily or to 100 for trips should be done by 6AM.

For now I am just going to keep it plugged in and not bother about charging time or duration.

 

[ScoobyDoo82]

Its good to hear I'm not the only one with 'subscription fatigue'. I also don't like giving my Tesla credentials to an unknown 3rd party.

With a 240v charging station, a single charge time during the night should be fine. With 120v, however, it may not provide enough charge for some days' driving.
possible short term solution: spend a bit more on electricity
possible long term solution: install 240 v charging station

Earl,

Just to clear up some confusion/misinformation.. when someone uses a 3rd party app or site for their Tesla, they are NEVER giving that 3rd party their Tesla username/password credentials.

Tesla doesn’t allow 3rd party access with simple. Username/password. When a 3rd party requests account information it is provided via an access token.

When a user attempts to log in with a 3rd party app/site, the login process is handed over to Tesla’s site. Once the credit credentials have been provided, the Tesla site grants the 3rd party site/app an access token and redirects the user back to the app/site.

Think of how many other apps have a “log in with Google/Facebook/Apple” method. This is the same thing.

The 3rd party never has or sees your log in credentials because the user is “handed off” to Tesla’s server when they are entering the log in credentials.

The 3rd party only can access the vehicle/account info because Tesla returned back with an authorization.

Hope this clears up the false fear of “giving your credentials”.

Additionally, if you still felt worried you could always set up 2FA (two-factor-authentication) for it to be virtually impossible for someone to use your account without authorization.

 

[ewoodrick]

Earl,

Just to clear up some confusion/misinformation.. when someone uses a 3rd party app or site for their Tesla, they are NEVER giving that 3rd party their Tesla username/password credentials.

I believe that would be better stated as "SHOULD NEVER need" just because you may not know of an app doing it, that, doesn't mean that there isn't an unscrupulous one that won't.

 

[Earl]

I believe that would be better stated as "SHOULD NEVER need" just because you may not know of an app doing it, that, just because you may not know of an app doing it, that, doesn't mean that there isn't an unscrupulous one that won't.

This hints at only one possible weakness. There are doubtlessly other possible attack surfaces.
And for the record, one only need worry about what unscrupulous ones can do, and only about weaknesses by the well intentioned.
I don't have time to try to wireshark the traffic from every app I use to figure out exactly where my data goes, nor do most folks who use them. Even then, there are mechanisms within the app by which the credentials can be snatched which operate solely on the server and are not visible to the user. The only way to remain secure is to not share your credentials with anyone other than Tesla and hope that Tesla doesn't do something stupid with them.

confusion/misinformation.. when someone uses a 3rd party app or site for their Tesla, they are NEVER giving that 3rd party their Tesla username/password credentials.

Thanks for the attempt at helping, however, it is this naive attitude that is why the whole field of cyber security exists. I find it most poorly understood by brilliant software developers who know a lot about how to write software at the high level using today's suites of nice development tools and programming languages but understand little about the underlying networking going on. I can't tell you how many times I've said "you did what?" to very intelligent software developers.
Hackers, on the other hand . . .

Think of how many other apps have a “log in with Google/Facebook/Apple” method

Anyone who is so lazy and naive that they use Google or Facebook (and probably Apple) so recklessly, clearly does not understand cyber security or privacy. The only reason Apple might be different is that we pay for many Apple products and services, therefore we are their customer, giving them some motivation to protect us. For Google and Facebook, we're just their product so they care only enough about us to avoid bad reports from a naive press.

 

[ScoobyDoo82]

This hints at only one possible weakness. There are doubtlessly other possible attack surfaces.
And for the record, one only need worry about what unscrupulous ones can do, and only about weaknesses by the well intentioned.
I don't have time to try to wireshark the traffic from every app I use to figure out exactly where my data goes, nor do most folks who use them. Even then, there are mechanisms within the app by which the credentials can be snatched which operate solely on the server and are not visible to the user. The only way to remain secure is to not share your credentials with anyone other than Tesla and hope that Tesla doesn't do something stupid with them.

Thanks for the attempt at helping, however, it is this naive attitude that is why the whole field of cyber security exists. I find it most poorly understood by brilliant software developers who know a lot about how to write software at the high level using today's suites of nice development tools and programming languages but understand little about the underlying networking going on. I can't tell you how many times I've said "you did what?" to very intelligent software developers.
Hackers, on the other hand . . .

Anyone who is so lazy and naive that they use Google or Facebook (and probably Apple) so recklessly, clearly does not understand cyber security or privacy. The only reason Apple might be different is that we pay for many Apple products and services, therefore we are their customer, giving them some motivation to protect us. For Google and Facebook, we're just their product so they care only enough about us to avoid bad reports from a naive press.

Saying that I have a naive attitude isn’t very nice. I have been safe and “attack-free” online from hacking attempts. In fact, you have further convinced me that you are the naive one here. The idea that Apple is safe and others are not because of your misunderstanding of services vs “we are the product” is absurd.

Cyber security doesn’t exist. Anything attached to an internet Connie’s potentially vulnerable. You completely missed my point. The simple fact that Tesla requires a 3rd party to exit their app and relay connections through their site is exactly an attempt to mitigate risk.

Additionally, none of your rebuttal makes any sense if you use 2FA. Which was another good point.

Go on and take this response apart and reply with some more FUD. It’s entertaining.

 

[Earl]

Cyber security doesn’t exist.

agreed