Automatically start charger to a given end time?

[Togg]

Another feature request:

I want to tell the car only when I want to have it charged and by how much, and then let the car figure out when to start charging, even if that be 3am.

In the future, this might also depend on knowing the lowest or most sensible electric rates. For example if the car knows that you want it to only charge during the solar day, then it would take this into account. (But for now keep it simple, and just start with having it automatically start charging in time to complete by when we want to use it.)

For example:

Say we want to leave with 100% charge at 8:00 AM. I'd rather not charge the car the night before, and I don't want to get up at 3am to plug it in. Instead I'd like to tell the car when we're leaving, and how much of a charge we want to have, and then have the car figure out when to start charging to achieve that goal.

(This is actually not my idea: I've have this neat nuro-fuzzy rice cooker that I just love that does just that. We tell it when the rice needs to be ready, e.g. by 6 pm, and no matter how much rice we put in it, 1, 2 or 3 cups, somehow it figures out when to start the cooking, and it is always done at exactly 6 pm. Neat eh?)

 

[TexasEV]

There’s no reason to “rather not charge the car the night before”. Plug in when you get home, as you always should do, and start charging to 90% (I’ve set my Teslas at 90% charge for the past six years anyway so that’s just routine). Then when you wake up, set the slider to 100% and let it charge when you’re getting ready. If it’s not at 100% when you leave it will be close enough. I don’t understand the “how much charge you want it to have” part. You should not want anything less than 100% charge when you’re leaving home on a trip.

 

[Eno Deb]

There’s no reason to “rather not charge the car the night before”.

How about people in colder climates who may want to finish charging right before they leave so the battery is warmed up?

You should not want anything less than 100% charge when you’re leaving home on a trip.

You should if you want regenerative braking to work and/or reaching the next supercharger on your route doesn't require that high a charge.

 

[stonelance]

Id like this feature as well, but I'm guessing there must be a 3rd party app that can do this already? Tesla seems slow to add features to their mobile app even though you would think they would be really easy to implement fully within the app. They must have a really small (or non dedicated) mobile app development team.

I can't imagine features like this are not yet implemented just because they haven't thought of them.

 

[TexasEV]

You should if you want regenerative braking to work and/or reaching the next supercharger on your route doesn't require that high a charge.

The OP is in San Francisco so the freezing climate tricks aren’t relevant to him. Charging to 100% will reduce your time the first supercharger regardless of how far away it is. For most people that’s more important than having the regen braking limited for a short time at the start of the trip.

 

[Eno Deb]

The OP is in San Francisco so the freezing climate tricks aren’t relevant to him.

Even if we assume that is true (SF can actually get pretty cold), it doesn't mean the feature wouldn't be useful for others.

Charging to 100% will reduce your time the first supercharger regardless of how far away it is.

No more than a few minutes compared to 90%. I would never charge to 100% unless I absolutely have to, since it causes a lot of stress for the battery (there is a reason why the car pops up a warning if you do it more than once).

For most people that’s more important than having the regen braking limited for a short time at the start of the trip.

Not for me.

 

[TexasEV]

I would never charge to 100% unless I absolutely have to, since it causes a lot of stress for the battery (there is a reason why the car pops up a warning if you do it more than once).
Not for me.

Actually the warning comes if you leave it set at 100% for three days, not if you do it more then once. It’s for people who set it to 100% for a trip and forget to set it back down. Charging to 100% and then driving the car is OK, it’s letting the battery sit at 100% that’s the problem. I charged my Model S to 100% dozens of times over 5 years while on trips, 90% routinely otherwise, and after the 5 years I owned the car I had only lost 5% of battery range. No one is going to do better than that no matter how they baby the battery.

 

[RTPEV]

The Nissan LEAF has always had this feature. You simply set an END time only in the charging schedule, and it will behave exactly as you describe (finish up just in time to leave). It's not a bad request at all. It doesn't matter that the OP lives in a climate that they might not be concerned about battery temp (maybe they are for reasons we don't know about).

 

[jerry33]

The Nissan LEAF has always had this feature. You simply set an END time only in the charging schedule, and it will behave exactly as you describe (finish up just in time to leave). It's not a bad request at all. It doesn't matter that the OP lives in a climate that they might not be concerned about battery temp (maybe they are for reasons we don't know about).

I think that Nissan can do this because there are really only two calculations to make: 120V/15 amps or 240V/32 amps. It would be much harder with a Tesla because of the variable number of amps, and because Tesla will reduce the amps if it sees a problem. (While it can't know this in advance, there could be a history kept for that location.) This is not an unsolvable problem, but solving it would use programming resources needed elsewhere. It would also reduce memory needed for other items to keep the charging history. Anyway, it only take a couple of charges for you to figure out how long it takes to charge at home.

 

[Eno Deb]

I think that Nissan can do this because there are really only two calculations to make: 120V/15 amps or 240V/32 amps. It would be much harder with a Tesla because of the variable number of amps

The car knows the maximum current at the location once plugged in (it's signaled by the Mobile Connector based on the plug type or by the Wall Connector based on the DIP switch setting), and it also knows (per location) if the user has reduced the charge rate. Making the calculation based on that should be fine.

and because Tesla will reduce the amps if it sees a problem.

The car only reduces the current if it detects an excessive voltage drop or an overheating plug, but I assume Nissan has similar protections.

This is not an unsolvable problem, but solving it would use programming resources needed elsewhere.

Pretty sure it would consume far less resources than "fart mode" ...

 

[jerry33]

The car only reduces the current if it detects an excessive voltage drop or an overheating plug, but I assume Nissan has similar protections.

The electricity in our area is dicey, with no sign of it changing (deregulation makes for lower prices but close to zero infrastructure maintenance/upgrading). There are often voltage sags. The Tesla reduces the amps, the Leaf does not.

 

[Eno Deb]

The electricity in our area is dicey, with no sign of it changing (deregulation makes for lower prices but close to zero infrastructure maintenance/upgrading). There are often voltage sags. The Tesla reduces the amps, the Leaf does not.

Well, if the voltage drops randomly it is just not possible to estimate the charge time accurately. By how much does the current drop?

I'd be surprised if the Nissan doesn't have circuit overload protection. Perhaps it simply doesn't trigger in your case because the max current is lower to begin with?

 

[seattlite2004]

Bolts also have "Departure" charging.

From the manual:

"Departure : The vehicle will
schedule charging to complete by
the programmed departure time.
The vehicle estimates the charging
schedule based on programmed
departure times, charge rate limits,
electric rate preference and
schedule, and priority charging
settings. If there is not sufficient
time after the charge cord is
plugged in, the vehicle will not be
fully charged by the departure time."​

 

[jerry33]

Well, if the voltage drops randomly it is just not possible to estimate the charge time accurately. By how much does the current drop?

I'd be surprised if the Nissan doesn't have circuit overload protection. Perhaps it simply doesn't trigger in your case because the max current is lower to begin with?

The Leaf does, but what happens when the voltage gets too low is that the charging just stops and does not continue. The Tesla is smarter than that.

The amount that the voltage drops varies.