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How to manually tell battery to preheat
- Thread starter tmxninja
- Start date
That is why I carefully said it does have battery heating, not a battery heater. It's not just cycling the coolant. It can actively run the coils in the motor as a heater to warm up that coolant.
gnuarm
Model X 100 with 72 amp chargers
I tried the preconditioning this morning on my model X and the windshield cracked in three places. I'm more than a bit unhappy.
Outside temp was barely below freezing and the cabin temp was in the 40's (F). I didn't see that I could control the defrosters in any way other than to not precondition at all. I'm wondering if this will be covered by the warranty. Being Sunday the support phone number is not being answered.
Outside temp was barely below freezing and the cabin temp was in the 40's (F). I didn't see that I could control the defrosters in any way other than to not precondition at all. I'm wondering if this will be covered by the warranty. Being Sunday the support phone number is not being answered.
I'm very doubtful that has anything to do with preheating. I've manually turned the defroster on when it was well below zero and still have the windshield. On the other hand we had a Subaru years ago the had a very small ding in the windshield from a stone. It sat there for months, then one day the windshield cracked all the way across and started flapping in the breeze! (That was really a shock!)
As far as I know, cabin preheat also turns on battery preheat. If you want to minimize power consumption, set low cabin temperature.
FWIW, when range-stretching, I preheat cabin while power is attached, then turn off climate control while driving.
If there was a chip in the glass from a stone impact, then cracking due to a temperature change isn't entirely unexpected. If there were no chips, then it should be pretty easy for the service center to determine that it was either a flaw in the glass or a stress crack and you should be able to convince them to cover it under warranty, especially if it is a newer vehicle.
gnuarm
Model X 100 with 72 amp chargers
In my case the service center replaced it without charge... but only after I received a bill and had to question it.
No, there were no chips in the glass. If there had been I would not have blamed the heating. There is a youtube video where Bjørn Nyland has the same thing happen to him. In his case he was testing the heater to see if it would melt a couple inches of snow. In my case it was barely below freezing with no precipitation.
This necessitated my first service center visit, but not my last. They didn't address everything I put in my online appointment report and while there I had someone look at the rear door that wasn't opening all the way. I've seen that before, but a lot of places I park have leaves just above the doors and I thought they were being overly cautious. The tech pointed out the display which indicates the detectors for the doors which were showing something there when no one was around. Now I need another appointment to fix those issues.
One thing that bothered me with the service visit was on dropping the car off they do a damage inspection like a car rental company. But the tech said I should sign that the car could not be inspected because it was "dirty" according to the form but in reality it was rain. I decided not to make a fuss about that. But on inspecting the loaner we went over every inch of that car even though it was wet. I won't be letting them off so easy next time.
BTW, I'm very glad I got an X. I'm 6'1" and I hit my head a lot in the model S I got. But then I hit my head some in the X from time to time. I'm just glad I'm not LeBron James.
BTW, I don't know that most of the techs in the service center are any better than any other car maker. At least not from this first visit. I guess that's not enough data to make an informed opinion though.
No, there were no chips in the glass. If there had been I would not have blamed the heating. There is a youtube video where Bjørn Nyland has the same thing happen to him. In his case he was testing the heater to see if it would melt a couple inches of snow. In my case it was barely below freezing with no precipitation.
This necessitated my first service center visit, but not my last. They didn't address everything I put in my online appointment report and while there I had someone look at the rear door that wasn't opening all the way. I've seen that before, but a lot of places I park have leaves just above the doors and I thought they were being overly cautious. The tech pointed out the display which indicates the detectors for the doors which were showing something there when no one was around. Now I need another appointment to fix those issues.
One thing that bothered me with the service visit was on dropping the car off they do a damage inspection like a car rental company. But the tech said I should sign that the car could not be inspected because it was "dirty" according to the form but in reality it was rain. I decided not to make a fuss about that. But on inspecting the loaner we went over every inch of that car even though it was wet. I won't be letting them off so easy next time.
BTW, I'm very glad I got an X. I'm 6'1" and I hit my head a lot in the model S I got. But then I hit my head some in the X from time to time. I'm just glad I'm not LeBron James.
BTW, I don't know that most of the techs in the service center are any better than any other car maker. At least not from this first visit. I guess that's not enough data to make an informed opinion though.
They have consistently been using that exact same tactic with everyone for years, so don't feel singled out. It does seem...not right.
gnuarm
Model X 100 with 72 amp chargers
No, just the opposite, I don't appreciate that they stoop to such a low level across the board. As I said, next time I won't be so "cooperative".
I'm actually a bit of a PITA when it comes to signing stuff. I always read every line and make sure I understand it all. I almost never test drove a Tesla because they wanted me to sign something saying I was responsible for all damage and something about being insured. I don't know if I'm insured for *their* car. I know my insurance has to cover anyone who drives my car, not just me. I expected they would have insurance that covers everyone who drives their cars. I had to put in a call to my insurance company and *add* collision to my 20 year old vehicle in order to insure their vehicle. Otherwise I would have been self insuring a $100k+ automobile.
You have to read and understand EVERYTHING you sign.
Lot of guessing follows:
Battery discharge is a lot more forgiving of cold temperature than battery charge so if you go to a supercharger with a cold battery the car will turn on its heater, warm the battery up pretty quickly and then ramp up the charge level to get you out of there faster. Lithium ion batteries do not have much internal resistance so just charging them doesn't heat them up much and this is why the heater is necessary when super charging. There is no other source of heat.
When charging from AC, however, there is another source of heat: the waste heat from the car's rectifiers. If you have a car with 17 kW chargers there is about 1.7 - 2.5 kW waste heat and this is collected from the rectifiers by the glycol loop. If there is no other use for the heat (i.e. the cabin heater is not on) would it make sense to dump that heat overboard? I don't think so but who knows?
Now at the same time if you have 17 kW of charging you can easily spare 4 kW for the battery heater and I am guessing the car will take that to warm the battery - if you have a big charger. If you are charging from a 14 - 50R with the new mobile charger that can only draw 32 amps for 7.6 kW then perhaps you don't have 4 kW to spare for the battery heater and/or perhaps 7.6 kW charging isn't too fast for your cold battery so perhaps the heater doesn't come on.
Based on this all I can suggest is that you try running the battery down and then charging it back up to finish about the time you are ready to leave on the theory that waste heat and/or battery heater powered from the wall will warm your battery. It might work. It might not. You'll just have to see. Of course someone else may know.
Battery discharge is a lot more forgiving of cold temperature than battery charge so if you go to a supercharger with a cold battery the car will turn on its heater, warm the battery up pretty quickly and then ramp up the charge level to get you out of there faster. Lithium ion batteries do not have much internal resistance so just charging them doesn't heat them up much and this is why the heater is necessary when super charging. There is no other source of heat.
When charging from AC, however, there is another source of heat: the waste heat from the car's rectifiers. If you have a car with 17 kW chargers there is about 1.7 - 2.5 kW waste heat and this is collected from the rectifiers by the glycol loop. If there is no other use for the heat (i.e. the cabin heater is not on) would it make sense to dump that heat overboard? I don't think so but who knows?
Now at the same time if you have 17 kW of charging you can easily spare 4 kW for the battery heater and I am guessing the car will take that to warm the battery - if you have a big charger. If you are charging from a 14 - 50R with the new mobile charger that can only draw 32 amps for 7.6 kW then perhaps you don't have 4 kW to spare for the battery heater and/or perhaps 7.6 kW charging isn't too fast for your cold battery so perhaps the heater doesn't come on.
Based on this all I can suggest is that you try running the battery down and then charging it back up to finish about the time you are ready to leave on the theory that waste heat and/or battery heater powered from the wall will warm your battery. It might work. It might not. You'll just have to see. Of course someone else may know.
I tried the method I proposed in #33 this morning and it worked (X100D with 72 amp charger). I could hear the circulation pump running while charging was going on and had the cabin heater off so all waste heat would go to the battery. Regen limitation dashes were displayed before commencement of charging and gone at completion. The caveat here is that the battery is huge and weighs a lot. It has to have a pretty substantial thermal mass and 2 kW isn't perhaps that much power relative to that mass so if the battery is cold enough when you start a couple of hours of charging may not deliver enough heat (2 hrs at 85% efficiency at 17 kW is 17.4 kBTU) to fully warm it. But if your charging source is stiff enough the car may turn on its battery heater. It's certainly worth a try.
A couple months ago, I changed my charging to scheduled so that it would finish charging within an hour or so of when I leave for week each day. While working Monday-Friday, I have had full regen in the morning on Tuesday-Friday consistently since that change. However, I do have a 72A onboard charger and 100A circuit HPWC in a garage that seldom drops below freezing. Additionally, the newest S & X vehicles don't have 72A onboard chargers even if they are P100D, so the results may not be the same for them (although it would be necessary to start charging sooner and charge longer, so that may be just as effective). Moreover, I believe OP was referring to heating the battery while NOT connected to a charging source, presumably because full regen is preferred even if it comes at a higher cost than limited regen.
gnuarm
Model X 100 with 72 amp chargers
I don't think your comment about the OP is completely correct.
Yes, he said there was no charging nearby but he is looking for better range, so using the battery to heat itself is not likely to help.
Is there a button you can push to turn on the battery heater? No, not AFAIK. So what can you do? Charge as close to departure as practical. No charger nearby? I have a 50' "extension cord" with a 14-50R on one end and 14-50P on the other (sold at RV outlets). Would that get you to a plug? Would two of those daisy chained?
The only other thing I can think of would be to get one of those temporary canvas "garages" that spring out of the ground like mushrooms in the fall in Quebec and put the car in there with a kerosene heater. I think they can get pretty warm inside even in a Quebec winter. I know a guy who says he worked comfortably on his boat in one throughout the winter.
Clearly I need to stop relying on recollection as long as you and ajdelange are around. At least the important part was correct.
Technically, you need to go to the next largest gauge to support the same amperage for each 100ft, and that's without connections. Daisy-chaining two of those would not be without risks, and at the very least, a lower charge limit should be pre-set in such a scenario.
These cords have No. 6 wire in them and that, with the lowest grade of insulation (60 °) is rated for 55 amps. With the Gen II mobile charger plugged in the vehicle will draw 32 Amps. No. 6 has resistance of 0.49 Ω/kft and a 50' cord has 100' of wire in it (out and return) for a total of 0.049 Ω. At 32 A voltage drop, for the single extension cord will be 1.568 V and power dissipation 50 W. Note that the cord is intended to be used in a 50 Amp circuit in which case dissipation would be more than twice this at 122 Watts. Plug two end to end and the voltage drop doubles to 3.136 V as does the power dissipation but note that the total power dissipation is less than half what the cord is designed to withstand and that the dissipation is now spread out over twice the length. Consider also that the 55 Amp rating for this wire is at 60 °C and OP is presumably at less than 0 °C. Thus there is clearly no risk to daisy chaining two, three or even four of these except perhaps to your wallet and back. They contain three pieces of #6 and presumably 1 of #8 and are, therefore, both expensive and heavy. You would, with 4 in series, lose 6.27 volts and thus, at 32 amp draw, obtain only 7479 Watts compared to 7630 with 1 (assuming 240 V at the outlet in both cases). There is certainly no need to reduce the charging current.
The NEC does require going to larger gauge if the run exceeds a certain length. That is done to insure that the voltage at receptacles is not degraded. But we are not wiring a building here. The code does not apply here, the car can clearly deal with the reduced voltage (down to 110) and we are not running in conduit, behind walls etc.
The NEC does require going to larger gauge if the run exceeds a certain length. That is done to insure that the voltage at receptacles is not degraded. But we are not wiring a building here. The code does not apply here, the car can clearly deal with the reduced voltage (down to 110) and we are not running in conduit, behind walls etc.
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