[Fryballin]

The temperatures here in KY have dropped down into the low 30’s and this morning just the upper twenties. I’ve noticed the truck giving me a message to “Plug the truck in” when I put it in park due to “outside air temperatures being low” according to the message. I keep the truck parked in a garage at home and plugged in each night. I do not have a convenient outlet near my parking spot at work to plug in while I’m at work for 8 hours each day. Is this message just a suggestion to keep the truck from using battery power while it’s parked to keep the battery above critical temps? Is it just to extend range when I start driving again because the battery will be pre-conditioned? Or is there any harm to the battery if in not plugging in when the temperatures are low?

 

[Leaf to Lightning : )]

if you have any pre-conditioning schedules set, it's likely due to it thinking that it will be using some of it's 'range' to accomplish that - it doesn't know if you are at work, coming back in 5 minutes or coming back in 5 days - no biggie.

 

[MPie]

It's to prevent potential battery wear based on temp. If it gets too cold, it's going to want to heat up the battery a bit, but it'll only do this if you're plugged in. This is assuming the truck works like the Mach e does.

Don't worry about it too much. It'll be fine sitting at work for 8 hours, especially at those mild temps. Just plug in when you can when it's cold or hot enough that those messages are appearing.

 

[chillaban]

It's to prevent potential battery wear based on temp. If it gets too cold, it's going to want to heat up the battery a bit, but it'll only do this if you're plugged in. This is assuming the truck works like the Mach e does.

Don't worry about it too much. It'll be fine sitting at work for 8 hours, especially at those mild temps. Just plug in when you can when it's cold or hot enough that those messages are appearing.

Does the MME / Lightning not condition at all when unplugged? Tesla still will warm/cool the pack but it just won’t do it to as ideal of a temperature range.

 

[Fryballin]

Does the MME / Lightning not condition at all when unplugged? Tesla still will warm/cool the pack but it just won’t do it to as ideal of a temperature range.

I was curious about this as well. I would hope there is some kind of precaution in place that if the battery needs to be warmed or cooled, and there is available battery power to do it, that it would prevent damage from the battery even when not plugged in. I could understand the notification as a way to remind drivers that leaving the truck plugged in when possible will preserve range for any departures. But at this point I’m thinking the truck does nothing to heat/cool the battery when its off UNLESS plugged in….

 

[chillaban]

Yeah for me my truck is parked outside on extremely frigid nights and storming nights and I tend to NOT plug it in because I don’t want to be digging a J1772 cable out of ice or risk our snow plowing service destroying the cable, or as I’ve seen before, sometimes those cables are so rigid below 0F that they’ll develop faults from simply bending/removing them.

I don’t mind if it negatively impacts range for my short drives around town. I would be more concerned if it harms the health of the battery.

 

[MPie]

Does the MME / Lightning not condition at all when unplugged? Tesla still will warm/cool the pack but it just won’t do it to as ideal of a temperature range.

I believe so. That is to say, the MME, and presumably the lightning, does nothing to automatically condition the battery if it's not plugged in. Not to be confused with pre-conditioning based on a departure time. That's different.

I wouldn't worry too much. It's asking you to do it if you're able, and if you're not, don't overthink it. The battery will be fine unless you live in an area that frequently experiences the most extreme temperatures.

 

[MPie]

Yeah for me my truck is parked outside on extremely frigid nights and storming nights and I tend to NOT plug it in because I don’t want to be digging a J1772 cable out of ice or risk our snow plowing service destroying the cable, or as I’ve seen before, sometimes those cables are so rigid below 0F that they’ll develop faults from simply bending/removing them.

I don’t mind if it negatively impacts range for my short drives around town. I would be more concerned if it harms the health of the battery.

If you set a departure time, the cable will be warm from using shore power to precondition.

 

[chillaban]

If you set a departure time, the cable will be warm from using shore power to precondition.

(1) if I’m not leaving, I don’t see any reason to burn 5-10kWh of on peak electricity for a departure precondition from 9 degrees.
(2) tried this and in 9 degrees F weather it didn’t work at all, my J1772 cable was still encased in ice with no signs of warmth. Maybe a thinner gauge cable would’ve worked better for this like the Tesla HPWC, but I ended up having to use the fancy quick melt road salt alternative to free the cable

 

[MPie]

(1) if I’m not leaving, I don’t see any reason to burn 5-10kWh of on peak electricity for a departure precondition from 9 degrees.
(2) tried this and in 9 degrees F weather it didn’t work at all, my J1772 cable was still encased in ice with no signs of warmth. Maybe a thinner gauge cable would’ve worked better for this like the Tesla HPWC, but I ended up having to use the fancy quick melt road salt alternative to free the cable

Not sure if it was intended since inflection is lost through text, but you're coming across as defensive. Hope that's not actually the case, as I'm only trying to help.

The only situation where I had charged in icy conditions, the plug and cable were all ice-free due to heat from power draw. Maybe it was charging and not just preconditioning. Preconditioning draws less power, thus less heat.

My mach e would use less than 1.5 kwh to precondition from my garage in low teens last winter. There is absolutely no way it will take 5-10 to precondition the truck, even at 9F outdoors. And yeah, you wouldn't want to precondition if you're not going anywhere and I did not suggest you should.

 

[chillaban]

Not sure if it was intended since inflection is lost through text, but you're coming across as defensive. Hope that's not actually the case, as I'm only trying to help.

The only situation where I had charged in icy conditions, the plug and cable were all ice-free due to heat from power draw. Maybe it was charging and not just preconditioning. Preconditioning draws less power, thus less heat.

My mach e would use less than 1.5 kwh to precondition from my garage in low teens last winter. There is absolutely no way it will take 5-10 to precondition the truck, even at 9F outdoors. And yeah, you wouldn't want to precondition if you're not going anywhere and I did not suggest you should.

Oh I appreciate your help, not being defensive. That was the coldest night this year and I did indeed measure that departure time drew 40A/240V for a half hour before I stopped it, and that is almost 5kWh. And the cable was still encased in frozen rain. It’s a cool idea though and maybe in less extreme weather it would have worked.

I suspect the sizing of the heaters in the Lightning is very different from the MME. We used to have an older Model X and a Model 3 and their power consumption was so dramatically different too for the same tasks.

 

[Kawartha Lightning]

How are you both measuring the energy draw for preconditioning activity? The diagnostic information from the app and the truck are very limited, so is this something you have metered in your house?

 

[MPie]

Oh I appreciate your help, not being defensive. That was the coldest night this year and I did indeed measure that departure time drew 40A/240V for a half hour before I stopped it, and that is almost 5kWh. And the cable was still encased in frozen rain. It’s a cool idea though and maybe in less extreme weather it would have worked.

I suspect the sizing of the heaters in the Lightning is very different from the MME. We used to have an older Model X and a Model 3 and their power consumption was so dramatically different too for the same tasks.

That's dramatically more power than I would have expected. I'm honestly shocked.

 

[MPie]

How are you both measuring the energy draw for preconditioning activity? The diagnostic information from the app and the truck are very limited, so is this something you have metered in your house?

I measured through the app for my EVSE, Chargepoint home flex.

 

[chillaban]

How are you both measuring the energy draw for preconditioning activity? The diagnostic information from the app and the truck are very limited, so is this something you have metered in your house?

I have a JuiceBox for my EVSE and it logs/graphs this info. Indeed the info in the app and car are really limited.

That's dramatically more power than I would have expected. I'm honestly shocked.

make that two of us! Yeah I didn’t even let it finish preparing the cabin before I unplugged and left. It still had a power limit around 90%. 5kWh is like how much I use to run the AC on a hot summer day here, especially painful in the winter when on peak starts at 7AM instead of 10AM.

 

[chillaban]

Just tried it again this morning, set a departure time for 8:30AM. About 45 minutes prior it started drawing power. JuiceBox says 3.5kWh so far and it still is “preparing for drive” at the full 38A my EVSE delivers.

outside temp is 12 F, car was parked outside overnight but it was charging until 2AM.

 

[Kawartha Lightning]

Interesting, so if its using say 5.0 kWh to pre-condition, that multiplied by the ToU rate (in my case it averages to about 10-cents per kWh -- would ballpark be about 50-cents to pre-heat in a mildly cold temp). Correct?

 

[chillaban]

Interesting, so if its using say 5.0 kWh to pre-condition, that multiplied by the ToU rate (in my case it averages to about 10-cents per kWh -- would ballpark be about 50-cents to pre-heat in a mildly cold temp). Correct?

Yeah, that sounds right. And if it's only mildly cold maybe it'll use less than 5kWh.

But here in California some of our TOU rates are 49 cents on-peak and 33 cents off-peak... plus our winter off-peak ends at 7AM which is too early for me to pre-heat anyway. It's also just a principle thing -- we run a highly energy efficient home and our total DAILY usage is averaging 3-4kWh, the fact that warming up the car in the morning is basically doubling our electricity bill feels a little awkward. I'm fine with that being the case on days that I actually am going somewhere.

It's more I'm responding to the earlier suggestion that thawing a J1772 cable by departure conditioning is not a palatable solution for me.

 

[Kawartha Lightning]

Yeah, that sounds right. And if it's only mildly cold maybe it'll use less than 5kWh.

But here in California some of our TOU rates are 49 cents on-peak and 33 cents off-peak... plus our winter off-peak ends at 7AM which is too early for me to pre-heat anyway. It's also just a principle thing -- we run a highly energy efficient home and our total DAILY usage is averaging 3-4kWh, the fact that warming up the car in the morning is basically doubling our electricity bill feels a little awkward. I'm fine with that being the case on days that I actually am going somewhere.

It's more I'm responding to the earlier suggestion that thawing a J1772 cable by departure conditioning is not a palatable solution for me.

 

[Kawartha Lightning]

Same experience in —what are mildly cold temperatures here right now, only -6°C (21F)— used 10 kWh so far, plugged in for only six hours, not charging at all, just the BMS doing its thing. It will easily use double that amount

overnight, which might be more than what I will use to drive to work the next day!