Suggestion for battery pre-heating and charge-end scheduling sent to Tesla

[boonedocks]

I have read through the owners manual and have tried to find where it says that turning on the cabin heater will pre-warm the battery pack. We haven't had a cold weather snap in Georgia yet so I haven't seen the regen-warning show up from having a cold battery. Is the "battery conditioning" anecdotal or is there really something to it? Just curious as to the "real" benefit of turning on the cabin HVAC to pre-condition the battery.
Thanks to all!!!

 

[jerry33]

I have read through the owners manual and have tried to find where it says that turning on the cabin heater will pre-warm the battery pack. We haven't had a cold weather snap in Georgia yet so I haven't seen the regen-warning show up from having a cold battery. Is the "battery conditioning" anecdotal or is there really something to it? Just curious as to the "real" benefit of turning on the cabin HVAC to pre-condition the battery.
Thanks to all!!!

When temperatures are around freezing, if I don't preheat the regen limit line is close to zero. With preheating it's around 30kW. If the charge time is set so that it finishes about departure time, it's over 30 kW and may even be gone.

 

[Andyw2100]

I have read through the owners manual and have tried to find where it says that turning on the cabin heater will pre-warm the battery pack. We haven't had a cold weather snap in Georgia yet so I haven't seen the regen-warning show up from having a cold battery. Is the "battery conditioning" anecdotal or is there really something to it? Just curious as to the "real" benefit of turning on the cabin HVAC to pre-condition the battery.
Thanks to all!!!

I don't believe there is anything in the manual about this, so I think you would say what we know about this comes from anecdotal evidence.

That being said, there is a great deal of anecdotal evidence on this topic, gathered by very well respected members here, (including posters like jerry33, who posted just above me) and accumulated over a fair amount of time. This is not just a handful of people guessing at what's going on.

There also may be some information that has been gleaned from service techs, or from diagnostic screens as well, but I'm not certain of that.

 

[Mjølner]

Are you suggesting that there is a difference in newer versions of the software?

My experience and others' has been that when it is very cold the preheating of the cabin would not fully eliminate the regen limit. Typically no matter how much we heated the cabin, the battery would heat only enough to reduce the regen limit to about 30 kW or so.

Is your issue that the battery can't heat beyond that, or that the new version of the software has reduced the ability to heat even to that point?

Sorry for late reply.
In my opinion, this came with the 7.0 software. After 4-5 hours charging, and cabin pre-heat directly before departure, i still don`t get more then 20kW Regen, and the yellow warning signal. Does the battery heat at all? Called Tesla yesterday, and everything is fine with the car they say
Me and and a large number of others also have a issue with the climate-control since 7.0, and i assume this is related.

 

[ArtInCT]

Sorry for late reply.
In my opinion, this came with the 7.0 software. After 4-5 hours charging, and cabin pre-heat directly before departure, i still don`t get more then 20kW Regen, and the yellow warning signal. Does the battery heat at all? Called Tesla yesterday, and everything is fine with the car they say
Me and and a large number of others also have a issue with the climate-control since 7.0, and i assume this is related.

Mjolner:
Can you describe to us the location of your car when it is charging and pre-heating? Is it in an enclosed garage or outdoors unprotected from the elements? Is the garage heated? If not heated, what is the temperature inside the garage during the recharge and pre-heat session?

 

[Dave85D]

Would disabling Range Mode when on shore power help? I'd rather 'see and set' the pack temperature, but Rang Mode disabling might be easier to implement.

 

[Mjølner]

Mjolner:
Can you describe to us the location of your car when it is charging and pre-heating? Is it in an enclosed garage or outdoors unprotected from the elements? Is the garage heated? If not heated, what is the temperature inside the garage during the recharge and pre-heat session?

The car is parked outside, unprotected, no garage, and same as my previous 2 Tesla`s. Same conditions. At the moment between about +2`C til -2`C.
Charging is 230Volt at 32A, witch has been enough to bring the battery to temperature on my earlier 2 cars(P85 and 85D)
At my current 85D and 7.0 software, all is changed.

As mentioned earlier, Range-Mode is off and NEVER in use, and i would also love to have more control on battery status and Pack temperature.

 

[Dave85D]

Would disabling Range Mode when on shore power help? I'd rather 'see and set' the pack temperature, but Rang Mode disabling might be easier to implement.

Should read *automatically disabling Range Mode* and *auto Range Mode disabling*

 

[Andyw2100]

Would disabling Range Mode when on shore power help? I'd rather 'see and set' the pack temperature, but Rang Mode disabling might be easier to implement.

Should read *automatically disabling Range Mode* and *auto Range Mode disabling*

The idea that you're getting at is something that I suggested back in the first letter, I believe, but with a simpler, more transparent implementation.

There is no need for Tesla to actually disable range mode when the car is on shore power. All that is needed is for Tesla to simply program things such that the car ignores any range mode limitations when on shore power. (You may consider this semantics, but I think there is a distinction.)

For example, we know that heating the cabin will not heat the battery pack with range mode on. Many of us with Ds want to leave range mode on all the time, to get the full benefits of torque sleep. But when it's cold, what we need to do is remember to toggle range mode off when we get home, and back on before we leave, so that we can warm our batteries with cabin preheating in an attempt to minimize the regen braking limit. There's no reason we should need to turn range mode off and back on. Tesla should just "override" range mode limitations when the car is on shore power.

If there are some people who, for some reason, would not want the car to override range mode when on shore power, then the override could be an option. It's an option I think many of us would select.

 

[jerry33]

Would disabling Range Mode when on shore power help? I'd rather 'see and set' the pack temperature, but Rang Mode disabling might be easier to implement.

Range mode needs to be disabled for preheating to heat the battery.

- - - Updated - - -

My experience and others' has been that when it is very cold the preheating of the cabin would not fully eliminate the regen limit. Typically no matter how much we heated the cabin, the battery would heat only enough to reduce the regen limit to about 30 kW or so.

That's what I've found unless the preheating is combined with charging. But compared to no preheating, that's a lot.

 

[dsm363]

Agree. Delay your charging so if finishes right before you leave. Or charge to 80% and when you wake up move slider to 90% and start charging.

 

[Andyw2100]

Agree. Delay your charging so if finishes right before you leave. Or charge to 80% and when you wake up move slider to 90% and start charging.

Most of us know what the work-arounds are. And we try hard to educate those who don't.

I'm hoping that Tesla will be responsive to what a large number of owners want, and provide the ability to preheat the battery directly (and enough to completely eliminate the regen limit) and also provide for charge-end scheduling, so we won't have to try to figure out exactly what time our charges need to start so that they end just before we leave, or, as you suggest, charge twice (first to 80%, and then to 90%), which is at least a little inefficient, since it heats the pack twice instead of once.

 

[Mjølner]

 

[Solarwind]

This is one of my pet peeves about the car. If you own a ICE car you can plug it in and have it near operating condition in cold weather. With a electric that is already plugged in you have to drive 50 miles before it is warm enough to have regen braking. I have tried charging the last 10% just before leaving, it helped but didn't solve the problem. Also if you don't drive shortly after charging in cold weather you may lose 15 or more miles of range a day even while plugged in.

 

[AWDtsla]

This is one of my pet peeves about the car. If you own a ICE car you can plug it in and have it near operating condition in cold weather. With a electric that is already plugged in you have to drive 50 miles before it is warm enough to have regen braking. I have tried charging the last 10% just before leaving, it helped but didn't solve the problem. Also if you don't drive shortly after charging in cold weather you may lose 15 or more miles of range a day even while plugged in.

I've never had a block heater come anywhere close to operating temp.

 

[Andyw2100]

This is one of my pet peeves about the car. If you own a ICE car you can plug it in and have it near operating condition in cold weather. With a electric that is already plugged in you have to drive 50 miles before it is warm enough to have regen braking. I have tried charging the last 10% just before leaving, it helped but didn't solve the problem. Also if you don't drive shortly after charging in cold weather you may lose 15 or more miles of range a day even while plugged in.

If this is an important issue for you please take a few minutes and write to [email protected], and let them know how you feel, and what features related to fixing this you'd like to see in future firmware versions. The more of us that do this, the greater the likelihood that Tesla will deliver the features we want to see.

Thanks!