Schedule charging to maximize battery heat in freezing weather

[GPinzone]

I'm thinking ahead for the winter months of freezing temperatures. I know charging the battery generates heat. Logically, I'd like to schedule my car to charge so that it finishes when I'm ready to leave for work in the morning. I know I can set the time to START the charge in the car, but there is no easy way to enter the time to STOP charging and then have it calculate and set the start time accordingly.

If the app would allow you to set the start time, I could just plug in the charger, then use the app to delay it based on the estimated charging info. Not convenient, but it could suffice.

 

[TexasEV]

Why do you need it to finish charging when you leave for work? Do you really need a 90% state of charge to commute to work? You could schedule it to start charging in the early morning hours, then whenever you’re ready to leave for work just unplug and go.

 

[Silver Ghost]

There is already a feature that allows one to delay the start of charging. I am not sure I understand your question fully

 

[GPinzone]

Why do you need it to finish charging when you leave for work? Do you really need a 90% state of charge to commute to work? You could schedule it to start charging in the early morning hours, then whenever you’re ready to leave for work just unplug and go.

It's winter. The battery range is decreaesed when it's extremely cold. Sure, you can drive it when it's not fully charged, but you have to consider the variables. Some days it might not be feasible to charge at all. Like when there's a blizzard.

There is already a feature that allows one to delay the start of charging. I am not sure I understand your question fully

Go back and reread what I wrote.

 

[NoBeard]

Yeah, I get your question.
It would be nice if the computer would track the historical charging curve and allow you to set a charging goal like "XX%@HH:MM" and have the car calculate the best estimate of time to start the charging so the battery would be at your target charge state and nice and warm when you get in. It already has the capacity to learn your work schedule and warm the car up, why not the battery?

 

[NoBeard]

To be fair the 2 previous respondents were from Texas, where cold is how they drink bad beer.

edit... to be clear, that's a joke.

 

[ratsbew]

You can just set 90% charge and set the start time so that it's still charging when you leave in the morning. In other words, set up the charging time/SOC so that it never finishes by the time you leave.

I have a dilemma because my time-of-use billing plan makes morning electricity more expensive. It may be cheaper (for me) to charge at off peak and then have the car be inefficient (heating the pack from battery power) during my morning commute.

 

[bryan995]

Agreed, it would be a great feature. For now I guess you can just calculate it each night and then set the start time accordingly. Kind of a pain. Maybe it’s easy via API to calculate and control?

 

[TexasEV]

You can just set 90% charge and set the start time so that it's still charging when you leave in the morning. In other words, set up the charging time/SOC so that it never finishes by the time you leave.

That’s what I was trying to say. I think people worried about charging being finished just before they leave may have owned a Leaf where they had to squeeze in every last electron. You have a 310 mile car. Even with reduced range in the cold, what difference will it make on your commute if you start with 70%, or 80%, or 90% charge? Unless you have a REALLY long commute.

 

[Silicon Desert]

Logically, I'd like to schedule my car to charge so that it finishes when I'm ready to leave for work in the morning. I know I can set the time to START the charge in the car, but there is no easy way to enter the time to STOP charging and then have it calculate and set the start time accordingly.

Yes, I would like that as well for the start of my long trips. Sure, there are workarounds that approximate a solution, but not as good as having a good stop charge time. This has been discussed in other threads and even requested in forums that support 3rd party apps.

 

[MX108]

That’s what I was trying to say. I think people worried about charging being finished just before they leave may have owned a Leaf where they had to squeeze in every last electron. You have a 310 mile car. Even with reduced range in the cold, what difference will it make on your commute if you start with 70%, or 80%, or 90% charge? Unless you have a REALLY long commute.

Funny you mention the LEAF, That was my first EV and it DID have the feature where I could basically say, on this day of the week at this time I want you to be at X% SOC and the computer did the rest.

One of the biggest things I miss with the X.

I've been playing with the Tesla API and I think that it would be possible in a stand alone app. Just don't have the time to pursue it.

 

[Jaguar]

I'm thinking ahead for the winter months of freezing temperatures. I know charging the battery generates heat. Logically, I'd like to schedule my car to charge so that it finishes when I'm ready to leave for work in the morning. I know I can set the time to START the charge in the car, but there is no easy way to enter the time to STOP charging and then have it calculate and set the start time accordingly.

If the app would allow you to set the start time, I could just plug in the charger, then use the app to delay it based on the estimated charging info. Not convenient, but it could suffice.

You can heat your battery using wall power by turning on climate control using the mobile app. This should make it more convenient to start battery heating even though it has nothing to do with charging.

 

[jdcollins5]

When you set your charge limit and start the charge the car will compute the estimated time to completion. You can stop the charge, set the start time based on the estimated time, so that it finishes before you leave for work.

 

[coleAK]

You set the charge limit then adjust the Amps in the car so the charging takes longer. The car tells how long to target based on amps set so you could do the math. I’m assuming you park outside? We’ve been in the single didgets (F) over the last 2 weeks most mornings I’m pulling out of a 55F garage and haven’t gotten the snowflake battery warning yet even when I drive home 10 hours later with temps ~20F outside.

 

[Sophias_dad]

I'm thinking ahead for the winter months of freezing temperatures. I know charging the battery generates heat. Logically, I'd like to schedule my car to charge so that it finishes when I'm ready to leave for work in the morning. I know I can set the time to START the charge in the car, but there is no easy way to enter the time to STOP charging and then have it calculate and set the start time accordingly.

If the app would allow you to set the start time, I could just plug in the charger, then use the app to delay it based on the estimated charging info. Not convenient, but it could suffice.

I haven't used it yet, but I'm sure the Dashboard for Tesla app allows you to set it to "start the charge at a time such that the battery is charge-complete at time X". The app is like $15, plus a few for the smart charging, for life.

 

[mswlogo]

The cheapest time to charge is when your battery is already naturally warmed up from driving home on your commute.

If you don’t take advantage of that naturally occurring heat, you’ll be throwing it away and paying $$$ to put that heat back.

Folks are way to hung up on maximizing regen at ALL costs.

Now if you need maximum range, or want to pay for a cozy car in the morning, or can’t drive it without regen, then go for for it.

Oh if you have off peak metering it might make sense too. Or some other special deal that it cost $0 at home and $X on the road.

Charge when your battery is already warmed up, so it can get down to putting watts in your battery rather than around it, immediately.

The goal isn’t max wh/mi on the car. It’s minimum total kWh on your electric meter/bill.

 

[RDoc]

T
The goal isn’t max wh/mi on the car. It’s minimum total kWh on your electric meter/bill.

That may well be your goal, but it's not everyone's. Having the battery preheat not only gives you more range, it lets regen work. This is a pretty trivial software feature that has been asked for over many years.

 

[mswlogo]

That may well be your goal, but it's not everyone's. Having the battery preheat not only gives you more range, it lets regen work. This is a pretty trivial software feature that has been asked for over many years.

I assumed most people bought into Tesla to save greenhouse gases and fuel costs. Not waste it.

Like I said, if you can’t drive without regen, go for it. You need to learn how to drive home without it on your commute home when cold.

The thread was referring to daily commute charging when cold. If you must have regen every day (one way) to make it range wise , you bought the wrong car or wrong range car.

 

[woodguyatl]

That may well be your goal, but it's not everyone's. Having the battery preheat not only gives you more range, it lets regen work. This is a pretty trivial software feature that has been asked for over many years.

Wouldn't it be tricky for the car to anticipate the future temperature changes if parked outside, amps available, and other variables if parked outside such that it could hit a specific charge level at a specific time? For instance, I can imagine a situation whereby the car gets fooled by a strong wind blowing on it at sub-zero temperatures causing the batteries to warm slowly and the charge to not complete on time.

I also suspect that Tesla has decided that the complaints from the general population and potential liability associated with cars not being charged on time exceeds the love they would get from us geeks.

 

[Silicon Desert]

When you set your charge limit and start the charge the car will compute the estimated time to completion. You can stop the charge, set the start time based on the estimated time, so that it finishes before you leave for work.

yup, and that is what I do, yet with such a smart car, it would be really easy for Tesla to do the same thing in software so I don't have to wast time with this process.