Software Update 2018.44.x

[MorrisonHiker]

So you bought a 100k car and you drive in a coat and gloves during winter?

No need for gloves if you have the heated steering wheel.

Honestly though, I really don't use the heater in my ~25 minute daily commute, even when it is below freezing. Normally the seat heaters are enough for me but sometimes I'll use the heated steering wheel. If there's someone else in the car or I'm on a longer trip, then I might turn on the heat.

 

[Magellan55]

So you bought a 100k car and you drive in a coat and gloves during winter?

Um, no. Just playing around to see what effect the heater has on battery usage. Today I set it to 68 with seat heater on low with outside temp 33, and that felt pretty good, given I did have a jacket on. But 22 miles later I got home to 350 Wh/mi. The car had been charging at work all day so the battery should have been warm already.

 

[Jan Fiala]

Um, no. Just playing around to see what effect the heater has on battery usage. Today I set it to 68 with seat heater on low with outside temp 33, and that felt pretty good, given I did have a jacket on. But 22 miles later I got home to 350 Wh/mi. The car had been charging at work all day so the battery should have been warm already.

Do not expect the battery to be warm when slowly charging outside. The trick is to preheat the car 30-60min prior departure or to schedule the start of the charging (with some reasonable power) so that the battery will be at the requested state of charge just prior departure.

 

[Magellan55]

Yeah I don't know the inner workings of the battery during charge, but I understand some power is used to heat the battery. Plus other lithium battery types get warm being charged, with no special heaters. It was a 6kw charger, and the car was only at 60% when I got in it, so wasn't tapering off. Today had similar environment, but wasn't charging this time. More or less same results.

Any other surprises as temps continue to drop? At what temp does power output get reduced?

 

[Asterix187]

I am on .44 and have just noticed the seats/air con toggle buttons are now on the right, not the left. I am in the UK so it may be a regional things?

 

[rnortman]

Yeah I don't know the inner workings of the battery during charge, but I understand some power is used to heat the battery. Plus other lithium battery types get warm being charged, with no special heaters. It was a 6kw charger, and the car was only at 60% when I got in it, so wasn't tapering off. Today had similar environment, but wasn't charging this time. More or less same results.

Any other surprises as temps continue to drop? At what temp does power output get reduced?

What you're missing is that the batteries have huge "thermal mass" (thermal capacity). It takes a lot of energy to raise their temperature by a small amount. Even plugged into a supercharger it takes a while for the waste heat of charging to warm up the battery -- supercharging a very cold battery starts out quite slow for the first 20-30 minutes in my experience while the battery warms up. I often charge on a slow 1kW charger and if it is cold the temperature of the battery may actually drop while charging. The quickest way to warm up the battery is to drive with a lot of speed changes and using the regen as much as possible. I also often charge with a 6kW charger in a garage that stays at around 50F/10C and even then I have slightly limited regen when leaving, unless I've been preconditioning (which turns on the battery heater) for several hours. A few minutes of preconditioning does nothing -- the battery heater is very low power relative to the thermal capacity of the batteries.

Power output is not reduced significantly until the battery is quite cold, below freezing I think. It's regen that will be limited.

The silver lining in all of this is that when you need range most -- road trips -- the battery will warm up reasonably quickly in the early part of the drive and then stay warm.

 

[Jan Fiala]

In a cold environment 6kW charging will not warm the battery at all. Unless the battery is very old with high internal resistance...

 

[Magellan55]

Another thing I just noticed with .44, but maybe it was introduced earlier - the rear camera now includes a pseudo-birds eye view of the car with nearby obstructions. not exactly a 360 camera view like many have asked for, but a step in the right direction. comes up automatically in reverse, and can be toggled on when just viewing the camera in other drive modes.

 

[MP3Mike]

Another thing I just noticed with .44, but maybe it was introduced earlier - the rear camera now includes a pseudo-birds eye view of the car with nearby obstructions. not exactly a 360 camera view like many have asked for, but a step in the right direction. comes up automatically in reverse, and can be toggled on when just viewing the camera in other drive modes.

@Magellan55 Can you take a picture of what this looks like and post it?

 

[croman]

Another thing I just noticed with .44, but maybe it was introduced earlier - the rear camera now includes a pseudo-birds eye view of the car with nearby obstructions. not exactly a 360 camera view like many have asked for, but a step in the right direction. comes up automatically in reverse, and can be toggled on when just viewing the camera in other drive modes.

Are you talking about the parking screen with the ultrasonics over the car image and the back up video on top?

Toggled with the parking cone button at low speed?

That's quite old. If different, that's quite exciting. Hopefully the latter.

 

[Magellan55]

Are you talking about the parking screen with the ultrasonics over the car image and the back up video on top?

Toggled with the parking cone button at low speed?

That's quite old. If different, that's quite exciting. Hopefully the latter.

Yeah that's it. How old is it? I don't recall that when I got my car this summer, when I was on various flavors of v8.

 

[croman]

Yeah that's it. How old is it? I don't recall that when I got my car this summer, when I was on various flavors of v8.

Before v8. Before I took delivery.