Manually warm up battery?

[Sam1]

Had a question, and seen someone else with the same inquiry on reddit.

M3P . Cooler temps, the battery is not nearly as responsive/powerful until (i'm guessing) a certain battery temp is reached. About 50 degrees outside, started at 90% capacity, raced a CTSV at 80%, the CTSV pulled on me when normally the same car loses fairly bad. Car felt underpowered. Run the battery down to 60% the same day, and the car feels like it has more power than it did at 80%. (guessing the batteries had warmed up by then)

Is there any option to preheat the batteries before leaving the house? Don't really care about consuming electric at the house. Only thing I could think of would be to run the HVAC on high for a while with the windows down... but that's not remotely a good solution.

Second question: is there any way that we can monitor battery temps realtime?

Thanks

 

[webbah]

Had a question, and seen someone else with the same inquiry on reddit.

M3P . Cooler temps, the battery is not nearly as responsive/powerful until (i'm guessing) a certain battery temp is reached. About 50 degrees outside, started at 90% capacity, raced a CTSV at 80%, the CTSV pulled on me when normally the same car loses fairly bad. Car felt underpowered. Run the battery down to 60% the same day, and the car feels like it has more power than it did at 80%. (guessing the batteries had warmed up by then)

Is there any option to preheat the batteries before leaving the house? Don't really care about consuming electric at the house. Only thing I could think of would be to run the HVAC on high for a while with the windows down... but that's not remotely a good solution.

Second question: is there any way that we can monitor battery temps realtime?

Thanks

Yes, use the app and turn climate to HI. You’ll need to do this for 15-30 minutes depending on how cold it is. Maybe longer.

For monitoring you’ll need to use ScanMyTesla on Android or TM-Spy on iOS. I’m not sure if TM-Spy can see the temps, but I’ll try it out later.

 

[Sam1]

Yes, use the app and turn climate to HI. You’ll need to do this for 15-30 minutes depending on how cold it is. Maybe longer.

For monitoring you’ll need to use ScanMyTesla on Android or TM-Spy on iOS. I’m not sure if TM-Spy can see the temps, but I’ll try it out later.

It seems like it would be more beneficial to just add a battery conditioning option on one of the menus. Instead of having to run the HVAC because that just wears out the HVAC system

 

[JulienW]

Heating the cabin doesn't really heat the battery. In fact the Model 3 doesn't have a battery heater the way the S/X do. It uses waste heat from the motors. One way is to Navigate to a Supercharger. This will start the "Precondition Battery for Supercharging". This sends energy to the motors and heats them up and then this waste is used to heat the battery.

 

[ucmndd]

I hate it when I get caught in those early morning street races with a cold battery. Really cramps your style when you live life a quarter mile at a time.

 

[eprosenx]

Had a question, and seen someone else with the same inquiry on reddit.

M3P . Cooler temps, the battery is not nearly as responsive/powerful until (i'm guessing) a certain battery temp is reached. About 50 degrees outside, started at 90% capacity, raced a CTSV at 80%, the CTSV pulled on me when normally the same car loses fairly bad. Car felt underpowered. Run the battery down to 60% the same day, and the car feels like it has more power than it did at 80%. (guessing the batteries had warmed up by then)

Is there any option to preheat the batteries before leaving the house? Don't really care about consuming electric at the house. Only thing I could think of would be to run the HVAC on high for a while with the windows down... but that's not remotely a good solution.

Second question: is there any way that we can monitor battery temps realtime?

Thanks

There is no way to only pre-warm the battery. The procedure is to turn on the climate control from the app before you leave and the car will prepare them cabin for you and pre warm the battery as necessary. (so it only does it on cold days)

I see no reason to set the climate control to “Hi”. Just regulate climate control is fine. The battery heating is separate from the cabin heating (but annoyingly the UI treats them as one and the same).

I pre warm the car this way every day. I actually can hear the high pitched whine slightly when I go outside to the car and it is using the motor for heating the battery. I also can see this behavior on my Sense Energy Monitor graphs. I have a 48a Wall Connector so it is great since it just uses shore power to preheat.

I also love the new “scheduled departure” feature. The car will delay charging till the early morning in order to try to keep as much residual heat in the battery when you get ready to go. It will also precondition the cabin (and presumably battery?) at the specific departure time (it finishes charging the battery by 6am in order to be nice to the grid).

 

[mswlogo]

There is no way to only pre-warm the battery. The procedure is to turn on the climate control from the app before you leave and the car will prepare them cabin for you and pre warm the battery as necessary. (so it only does it on cold days)

I see no reason to set the climate control to “Hi”. Just regulate climate control is fine. The battery heating is separate from the cabin heating (but annoyingly the UI treats them as one and the same).

I pre warm the car this way every day. I actually can hear the high pitched whine slightly when I go outside to the car and it is using the motor for heating the battery. I also can see this behavior on my Sense Energy Monitor graphs. I have a 48a Wall Connector so it is great since it just uses shore power to preheat.

I also love the new “scheduled departure” feature. The car will delay charging till the early morning in order to try to keep as much residual heat in the battery when you get ready to go. It will also precondition the cabin (and presumably battery?) at the specific departure time (it finishes charging the battery by 6am in order to be nice to the grid).

As @JulienW pointed out the Model 3 does not heat the battery by running cabin heat. It does slightly heat it by putting load on the battery. But it’s not running the motors to heat the battery. Model S/X does heat battery with Range Mode Off.

Another way to heat it, is scheduled charging but that might not heat it to much depending on your charge rate.

 

[webbah]

As @JulienW pointed out the Model 3 does not heat the battery by running cabin heat. It does slightly heat it by putting load on the battery. But it’s not running the motors to heat the battery. Model S/X does heat battery with Range Mode Off.

Another way to heat it, is scheduled charging but that might not heat it to much depending on your charge rate.

This is false. It does use the motor stators to preheat the battery. This is a function of the magnet based motor vs the Model S and X which have dedicated battery heaters. It is not simply putting load on the battery. Only 2 ways to do this. Navigate to a Supercharger or use the cabin heater control to activate the motor stators.

 

[mswlogo]

This is false. It does use the motor stators to preheat the battery. This is a function of the magnet based motor vs the Model S and X which have dedicated battery heaters. It is not simply putting load on the battery. Only 2 ways to do this. Navigate to a Supercharger or use the cabin heater control to activate the motor stators.

We may be both right. Model 3 May heat the battery using motors when preheating cabin to get full propulsion (to remove snowflake). But it will not heat to regain regen (which is what I think most people are thinking).

Where as Model S/X will heat the battery with its dedicated heater when preheating cabin (range mode off) to get a certain percentage of regen (but not all of it).

I noticed Model 3 often had a snow flake when I’ve yet to see a snow flake on Model X. But when Model 3 would often have some regen, Model X has absolutely none.

All models will heat for better charging temperatures.

Model S/X will heat while driving if Range Mode Off and does nothing special enroute to supercharger.

Model 3 will heat battery while driving enroute to a supercharger. Not sure if it might heat when snow flake is up. My guess is, it does not. (I think it would display it like it does for supercharger if it did). It always does some natural battery heating from normal driving because motor heat can route to battery.

I think the mobile app cabin view will show battery heating the same way on all models. With a red battery icon.

@JulienW

See here

Preheating battery in cold weather use.

 

[webbah]

This is a pretty good video from Bjorn Nyland, however it is mostly about charging in winter and cold battery analysis.

 

[SSedan]

And for many of us with the S anyway updates last year killed the battery heating with cabin preheat. Have tickled below zero here already this winter and seen no battery heating outside charging.

 

[mswlogo]

And for many of us with the S anyway updates last year killed the battery heating with cabin preheat. Have tickled below zero here already this winter and seen no battery heating outside charging.

I don’t know when it was lost because I’ve not had the X long nor do I like wasting energy and adding unnecessary heat cycles to the battery, so I never preheat the Battery or the Cabin. I normally keep Range Mode on (unless headed to SuoerCharger or car is covered in Ice). But it is confirmed working again by myself and others on 2019.40.50.7.

 

[MD-2000]

My concern - if I preheat the cabin on my Model 3 (AWD-LR) while plugged in at home, will it use the wall power or drain the battery, since by then scheduled charging is complete? So is there any benefit to pre-heating more than 2 or 3 minutes? Or does the car not care if I am plugged in or not, since charging is complete, will use the battery charge? After all, the whole point of heating while still plugged in is to not drain the battery unnecessarily... and I assume it would not need all 40A from the wall at 8AM to heat the cabin or battery?

(Also noted recently that the car will start throwing cool air after heating for a while while driving - the last time, a reboot fixed this.)

 

[Brock-WI]

If your plugged in to grid power (and don't have off peak times set) it will pull the max it can from grid power and if it needs more it will pull from the battery, but once it warms the cabin to the set temp and that heater ramps down it will start adding the battery power back to your battery set point if it used some of the battery during warm up.

Each motor or stator can consume about 3.5 kW and I have seen the cabin heater pulling 6 kW so that would be 13kw (54 amps from the wall). In that case it would use the 40 amps (9.6 kW) from the wall and approximately 3 kW from the battery. But again the cabin heater will likely draw down to 2 to 3 kW (less as the cabin is warm) making the total about 9 kW or about 38 amps from the wall.

 

[MD-2000]

Thanks. So even though I scheduled a charge cycle, where I start at 1AM, so usually 2 to 4 hours and then it's done - if at 8AM if I say "warm up" it will begin using wall current again? I have no peak metering or time-of-day power charge differentials, so nothing programmed. It's a straight 8.625 cents/kWh any time.

 

[toolman335]

I have a supercharger near my house. I frequently lie to my car to say I'm going to it so the battery is preconditioned. The guilt is overwhelming!

 

[hcdavis3]

Scheduled departure warms the battery and the cabin in addition to giving you full regen.

 

[Brock-WI]

So even though I scheduled a charge cycle, where I start at 1AM, so usually 2 to 4 hours and then it's done - if at 8AM if I say "warm up" it will begin using wall current again?

Yes it will turn the EVSE back on and start drawing power from the wall. Even if was only a 15 a 120 vac outlet it will do this. And the way you have it is best as the battery will already be at your set point so it isn't trying to calculate what it needs to charge the battery and what it needs to heat up, although the car WAY overestimates this usually and finishes charging / heating early.

 

[Gasaraki]

My concern - if I preheat the cabin on my Model 3 (AWD-LR) while plugged in at home, will it use the wall power or drain the battery, since by then scheduled charging is complete? So is there any benefit to pre-heating more than 2 or 3 minutes? Or does the car not care if I am plugged in or not, since charging is complete, will use the battery charge? After all, the whole point of heating while still plugged in is to not drain the battery unnecessarily... and I assume it would not need all 40A from the wall at 8AM to heat the cabin or battery?

(Also noted recently that the car will start throwing cool air after heating for a while while driving - the last time, a reboot fixed this.)

It will pull wall power

 

[GtiMart]

The 2021 models are confusing a bit because of the heat pump and octovalve so things are a bit different. 2018-2020 models like mine do heat the battery when you heat the cabin, by generating heat in the motors. Motor heat goes to the battery while PTC heat goes into the cabin. There is no separate switch unfortunately, and no way to disable battery heating either. I believe this will heat the battery until it reaches around 21C, which is where you get most if not all of your regen back. 21C is much higher than the temperature where the snowflake disappears. You will also have most of your acceleration power at that temperature. There seems to be other factors that influence maximum regen and power output... maybe recent firmware changes. I was sure that by 21C I had full 85kW of regen but the last time I checked with ScanMyTesla I only had around 70kW at that battery temperature (at 89% SOC).
Preconditioning for a supercharger will heat the battery higher than 21C, I just don't know what the upper limit is. I've arrived to a SC at ~35C I believe, once. I don't drive enough to have multiple test points to compare.