Two Unrelated UI/Feature questions

[LMichel]

I've noticed that my round Power Usage Graph displayed on the dash will frequently show a yellow-dotted line in the negative region when the car is freshly charged. At first I thought this was because the batteries were so topped off that any regen would essentially have nowhere to go and might be 'less effective?' for a while.
However, this also happens when the car is only at 80% SOC - so plenty of room for some regen energy.
Further, there are times when a yellow "!" triangle also shows on the graph in the same area.
After a few miles, this goes away and everything is fine. The car doesn't seem to respond differently when this happens, it just bugs me. Whats going on?

Unrelated, I noticed that when I use the fob to unlock the charger so I can unplug, that sometimes the charge door closes on its own and sometimes it does not. If I ignore it and get into the car, it closes anyway. But why does it sometimes wait til I get in and sometimes close almost immediately?

Such a curious machine this thing is...

 

[NewTMSMan]

Was it cold out by any chance when you see the yellow "!" warning symbol? I believe this is a warning that full power is not available due to the batteries not being warm and it goes away after a short period of time when they warm up.

A pic would help answer the rest as it is not clear exactly what you mean "yellow" dotted line. The dashed line on the graph is the EPA combined rated Wh/mi. The numbers around the circle are not the scale for the graph, they are completely separate and only indicate instant power draw / regen.

Charger port I cannot explain.

 

[kmistry1986]

I believe the yellow line or triangle means regenerative braking is temporarily disabled as the battery is fully charged. It goes away after there is enough room in the battery to allow it to be charged through regen. I thought I read that somewhere here a while back but I could be wrong.

 

[kavyboy]

I also sometimes get the yellow regen triangle when I start the car. It can be on a perfectly mild day, so there shouldn't be too hot or cold. It seems random, and it goes away so fast I never notice if there's a dotted line or not.
I made a service appointment, but the service center said there were no faults reported on the log, and not to worry about it.

 

[kort677]

I also sometimes get the yellow regen triangle when I start the car. It can be on a perfectly mild day, so there shouldn't be too hot or cold. It seems random, and it goes away so fast I never notice if there's a dotted line or not.
I made a service appointment, but the service center said there were no faults reported on the log, and not to worry about it.

what is the SOC when you see the regen limits?

 

[kavyboy]

what is the SOC when you see the regen limits?

Either about 89% or 49%. I usually charge to either 50 or 90 percent overnight, and it happens on grocery runs and short trips later. It may happen on longer trips as well, but I don't even notice it anymore.

 

[12Pack]

Indeed the yellow dotted line indicates regen is limited to the region above where the dotted line starts. Now that is getting cooler have started to have that appear when I leave work. But because I have the battery charging just before I leave home (which warms it up) , it rarely appears then.

 

[wayner]

Get used to the yellow dotted line as you will be seeing it a lot for the next six months. It is temperature related as the batteries don't charge at all or as well when they are cold. In my experience this kicks in when the ambient temperature is below 12C or 55F. When it is really cold the yellow arc will be larger. You may notice a difference in the driving as you may have to use your brakes more as regen working will not work as much to slow the car when you see the yellow arc.

One way to minimize this is to time your charging so that it ends just before you start driving - this is easiest to do for overnight charging at home. For example, I leave for work a little after 7am. So in an ideal world I would charge my car so that the charging just finishes before 7 - this also makes sense as my electricity rate goes up at 7am as well.

FYI - before the car can charge the batteries have to be warmed up. When it is really cold during the heart of winter you can use a lot of power to just keep the batteries warm. So plugging into a normal 120V outlet will barely charge the car at all since the power first has to go to warming the batteries and keeping them warm. I believe that takes at least 1kW and you only get about 1.5kW out of the typical plug at 120V and 12A.

Here's a great blog entry by TMC moderator @Doug_G on cold weather driving: Cold Weather Driving

Some other things to look forward to over the winter - when you car getscovered with snow/slush/ice it can affect the sensors/cameras/etc so this can stop AP from working. IMHO the sensor under the front bumper on AP1 Model S's was not well designed as it will easily fill up with snow/slush. Also, when the roads are covered with snow the Tesla can't read the lane markers so that can also prevent AP from working.

 

[LMichel]

@wayner Awesome comments. Thanks for the pointers! Thanks to other responders as well.
Ok, this make sense. This started happening with the crisp, fall mornings up here in the northeast.
Hmmm.. So I have a L2 charger - used for the Volt that I sold to get the S75D. Pretty sure it provides about 3.5kw. I never really cared to change it out, because I thought slower charging was healthier charging??
Also, I have a solar array and tell the charging schedule not to bother until 10AM. This way, the sun is up over the panels and my Tesla charging is totally free Sure I'm selling less back to the grid, but the price they give me per KWh is peanuts anyway...
Interesting, if my SOC is only 80% or so, you would think regen could push to the battery regardless of temp. My Volt always did. It was hardcoded to essentially read as depleted at 20% and fully charged at 80%.
The very first thing I do when I leave my garage is head down a pretty steep grade for 2 miles. When I get to the bottom, the Wh/Mile for the trip is always negative. I get it, all that regen has nowhere to go if the battery is at 100%. Not sure why it can't at 80% and cold temps, but ok

 

[Saghost]

Get used to the yellow dotted line as you will be seeing it a lot for the next six months. It is temperature related as the batteries don't charge at all or as well when they are cold. In my experience this kicks in when the ambient temperature is below 12C or 55F. When it is really cold the yellow arc will be larger. You may notice a difference in the driving as you may have to use your brakes more as regen working will not work as much to slow the car when you see the yellow arc.

One way to minimize this is to time your charging so that it ends just before you start driving - this is easiest to do for overnight charging at home. For example, I leave for work a little after 7am. So in an ideal world I would charge my car so that the charging just finishes before 7 - this also makes sense as my electricity rate goes up at 7am as well.

FYI - before the car can charge the batteries have to be warmed up. When it is really cold during the heart of winter you can use a lot of power to just keep the batteries warm. So plugging into a normal 120V outlet will barely charge the car at all since the power first has to go to warming the batteries and keeping them warm. I believe that takes at least 1kW and you only get about 1.5kW out of the typical plug at 120V and 12A.

Here's a great blog entry by TMC moderator @Doug_G on cold weather driving: Cold Weather Driving

Some other things to look forward to over the winter - when you car getscovered with snow/slush/ice it can affect the sensors/cameras/etc so this can stop AP from working. IMHO the sensor under the front bumper on AP1 Model S's was not well designed as it will easily fill up with snow/slush. Also, when the roads are covered with snow the Tesla can't read the lane markers so that can also prevent AP from working.

Generally good information/advice. One clarification, though: the yellow line and regen limitation has nothing at all to do with ambient temperatures - it's all about the battery pack temperature. It can be twenty below outside and you can still have full regen available - if the pack is toasty warm from a Supercharging session or long drive.

You kinda get back to that point later in the post, with the (wise) idea of scheduling charging for the morning hours, but I didn't want the ambient part confusing people.

 

[Saghost]

@wayner Awesome comments. Thanks for the pointers! Thanks to other responders as well.
Ok, this make sense. This started happening with the crisp, fall mornings up here in the northeast.
Hmmm.. So I have a L2 charger - used for the Volt that I sold to get the S75D. Pretty sure it provides about 3.5kw. I never really cared to change it out, because I thought slower charging was healthier charging??
Also, I have a solar array and tell the charging schedule not to bother until 10AM. This way, the sun is up over the panels and my Tesla charging is totally free Sure I'm selling less back to the grid, but the price they give me per KWh is peanuts anyway...
Interesting, if my SOC is only 80% or so, you would think regen could push to the battery regardless of temp. My Volt always did. It was hardcoded to essentially read as depleted at 20% and fully charged at 80%.
The very first thing I do when I leave my garage is head down a pretty steep grade for 2 miles. When I get to the bottom, the Wh/Mile for the trip is always negative. I get it, all that regen has nowhere to go if the battery is at 100%. Not sure why it can't at 80% and cold temps, but ok

The Volt chemistry is different, and more tolerant of charging in the cold. The Volt pack is also better insulated I believe, with less exposed outside surface, so it'll stay warmer overnight. And, of course, with the blended brakes it can always swap in friction braking seamlessly (though if you're driving in L and not on the brakes you'll know when the regen cuts.)

 

[wayner]

Generally good information/advice. One clarification, though: the yellow line and regen limitation has nothing at all to do with ambient temperatures - it's all about the battery pack temperature. It can be twenty below outside and you can still have full regen available - if the pack is toasty warm from a Supercharging session or long drive.

You kinda get back to that point later in the post, with the (wise) idea of scheduling charging for the morning hours, but I didn't want the ambient part confusing people.

Very true - I should have said battery temperature.

 

[LMichel]

Always drove that Volt in "L". Loved it.. Just had to be careful not to get rear-ended..

 

[12Pack]

Also seems that Tesla goes to great lengths to charge batteries in a tight temperature range, which pays back with longer battery life. I’d rather have that than the loss of a some regen every now and then.

 

[gregincal]

Generally good information/advice. One clarification, though: the yellow line and regen limitation has nothing at all to do with ambient temperatures - it's all about the battery pack temperature. It can be twenty below outside and you can still have full regen available - if the pack is toasty warm from a Supercharging session or long drive.

You kinda get back to that point later in the post, with the (wise) idea of scheduling charging for the morning hours, but I didn't want the ambient part confusing people.

And the reverse can be true as well. It happens to me all the time that I go out to the garage in the morning and it's mild, but the battery hasn't had a chance to warm up from the cold overnight temperatures (especially since the battery is down next to the cement floor, which also hasn't warmed up yet), so I get the regen limit.

 

[kort677]

re regen limit. when visiting co a couple of winters ago I noticed a regen limitation for the first time. the car had been spending the nights in +5-+10f and one morning I went for a drive, within 5 miles the regen limitations were gone. to me it surely is something to be aware of but nothing to be so overly concerned about.

 

[Saghost]

re regen limit. when visiting co a couple of winters ago I noticed a regen limitation for the first time. the car had been spending the nights in +5-+10f and one morning I went for a drive, within 5 miles the regen limitations were gone. to me it surely is something to be aware of but nothing to be so overly concerned about.

I usually had a regen limit for my entire drive home (10 miles/20 minutes) last winter, after the car had cold soaked unplugged all day. In the mornings, setting it to charge right before I left made a difference but didn't always prevent it from happening.

 

[scottm]

If you think yellow dashed is interesting, wait until you get the blue snowflake symbol by the battery on REALLY cold days...

Zero regen no matter what the SOC is.

And power delivery is severely restricted... putt putt putt..

And the pack is possibly too cold to accept charging from low power sources (anything below about 3.5kW.. so forget 120VAC UMC it will not start the charge cycle). In order to charge, you'll need to warm the pack first by driving or physically moving (towing?) the car to sheltered area that is "warmer" so the pack can thaw. Or plug into a much higher power capable charging source so the car can make heat for thawing batteries from shore power.... but maybe you'll never see such cold.

Tesla does not want you to leave your car cold soaking below (-20C or -30C I forget..) for more than 24 hrs.