Disappointed with cold-soak battery range (no garage) Or is it just me?

[Brass Guy]

That post was also speculation. My conclusion is based on energy use with certain features and range mode on or off, and how long before regen is available; which I believe is directly related to battery temperature, evidenced by the fact that the battery charges at a much reduced rate when it's very cold.

 

[sauce]

I'm sorry folks but so far with all due respect I find the explanations somewhat short. I don't like that we are being limited to this when with simple programming we could have the convenience of deciding when we wish to heat the battery up.

I get the idea of timing the charging to get to 90% or 100% around the time I should be ready to leave in order to take advantage of a warmer battery due to charging. That is fine, but doesn't cut it if you ask me. 2 reasons for this:

1) This requires additional and unnecessary planning to get optimal battery temperature whereas a simple addition to the Tesla App/On-board OS could easily fix this as far as I know.

2) Charging as soon as you get home (not to 100% I know) allows the car to be ready to be driven sooner. Does everybody here live in a set world where you drive home at 5-6-7PM and you never need to use the car before 6-7AM to go back to work?

• What if you get a call from a sick parent late and out of town where you will need the car with decent range?
• What if you get a last minute invitation?
• What if your pregnant wife gets a craving and you must drive around to find the frikkin fried pickles?
• What if... you get a late night booty call!!! ''Uh, no can't do car's charging is scheduled to start in half an hour and you're 20 minutes drive away.'' How about hitting your head with a skillet for missing that booty call?

Ok you get my point. It should be simple enough to be able to separate charging from conditioning the battery pack. In fact, from what I've seen in this thread and other threads, pre-2016 cars seem to be able to control this to some extent since for those cars conditioning heats up the interior AND the battery pack.

But for some reason this is not possible with the facelift cars. There must be a good reason for this and I'd be curious about knowing.

Come to think about it, up in the great white north where I grew up we all had block heaters that allowed to warm up the engine block so we could actually a) start the car in -30C weather, and B) actually pull some heat a little quicker. Now, in order for people to understand that EVs are every bit as practical as their ICE counterparts, they should actually be able to do everything an ICE can do and that includes sitting it outside during the harshest of winter nights. You plug the EV like you'd do with an ICE. But then it has to have the capability of actually heating the pack up no?

And yes, my Model S will sit outside this winter no matter what because I don't have a garage. It's a Model S, not a princess.

 

[whitex]

In fact, from what I've seen in this thread and other threads, pre-2016 cars seem to be able to control this to some extent since for those cars conditioning heats up the interior AND the battery pack.

I have a 2015 and no preheating of battery (see my earlier post). From what I recall, 2013 I used to have wasn't any different, and the 2017 we also have seems the same in that regard. If I was to speculate on this, the battery heater is not that powerful and its main purpose is to keep the battery from freezing. The reason the batteries heat up much better when charging is because of the charging inefficiencies which produce heat in each cell. Same when you start driving the car. Another data point to support this, Ludicrous Max power mode heats up the battery. Starting from normal operating battery temperature (full regen on), it takes 45-120minutes depending on outside temp - this using just the heater. A few 0-60 full throttle will get you there in as little as 10 minutes or less.

 

[Brian-MS90D]

@sauce, pretty sure you have live with the reality of physics or build a garage. Sorry for the bad news. The good news is that I still think electric cars in cold temps are very practical. The vast majority of owners - including me - do not care about optimizing regen.

 

[Dax279]

I'm sorry folks but so far with all due respect I find the explanations somewhat short. I don't like that we are being limited to this when with simple programming we could have the convenience of deciding when we wish to heat the battery up.

I get the idea of timing the charging to get to 90% or 100% around the time I should be ready to leave in order to take advantage of a warmer battery due to charging. That is fine, but doesn't cut it if you ask me. 2 reasons for this:

1) This requires additional and unnecessary planning to get optimal battery temperature whereas a simple addition to the Tesla App/On-board OS could easily fix this as far as I know.

2) Charging as soon as you get home (not to 100% I know) allows the car to be ready to be driven sooner. Does everybody here live in a set world where you drive home at 5-6-7PM and you never need to use the car before 6-7AM to go back to work?

• What if you get a call from a sick parent late and out of town where you will need the car with decent range?
• What if you get a last minute invitation?
• What if your pregnant wife gets a craving and you must drive around to find the frikkin fried pickles?
• What if... you get a late night booty call!!! ''Uh, no can't do car's charging is scheduled to start in half an hour and you're 20 minutes drive away.'' How about hitting your head with a skillet for missing that booty call?

Ok you get my point. It should be simple enough to be able to separate charging from conditioning the battery pack. In fact, from what I've seen in this thread and other threads, pre-2016 cars seem to be able to control this to some extent since for those cars conditioning heats up the interior AND the battery pack.

But for some reason this is not possible with the facelift cars. There must be a good reason for this and I'd be curious about knowing.

Come to think about it, up in the great white north where I grew up we all had block heaters that allowed to warm up the engine block so we could actually a) start the car in -30C weather, and B) actually pull some heat a little quicker. Now, in order for people to understand that EVs are every bit as practical as their ICE counterparts, they should actually be able to do everything an ICE can do and that includes sitting it outside during the harshest of winter nights. You plug the EV like you'd do with an ICE. But then it has to have the capability of actually heating the pack up no?

And yes, my Model S will sit outside this winter no matter what because I don't have a garage. It's a Model S, not a princess.

While I agree with your comments, could you not turn down the rate at which the car charges overnight so that it charges for longer. This way if one of those surprises arise you would have added some sort of charge to the pack?

For me, I tend to ensure that I have enough range to get me to a Supercharger each night (actually not the closest one) so that I know if an emergency came up and needed me to drive a distance I could get to that charger and then quickly add range. This happened to me last year when I had a family emergency over 600 Kms away and I ended up adding only 30 mins to my trip, but it also let me get 30 mins of more sleep for my drive as the call came in at 2 in the morning.

 

[mspohr]

What does Range Mode do?
Range Mode saves power by automatically limiting the amount of power the climate control system uses to maintain the temperature of the battery and the interior cabin. You can turn on this setting by tapping Controls > Driving > Range Mode.

 

[David29]

What does Range Mode do?
Range Mode saves power by automatically limiting the amount of power the climate control system uses to maintain the temperature of the battery and the interior cabin. You can turn on this setting by tapping Controls > Driving > Range Mode.

And, in the same vein, my owner's manual says:

"If Model S is plugged in, you can heat your Battery using wall power by turning on climate control using the mobile app. When the Battery warms up, the blue portion on the meter and the snowflake image are no longer displayed."

This is one of those instances in which I wish Tesla was a bit more informative about how the car works. As is evidenced from this thread, there is considerable confusion around how the car manages the battery temperature, what the parameters are, and how best to operate the car for best efficiency. The manual does not tell us what the battery temperature is that would cause the heater to go on when the cabin heater is operated from the app, or whether or not there is some upper limit that causes the heater to shut off.

There is nothing in the manual to suggest that Range Mode warms the battery, either, so I wonder what the basis is of the post that said that is part of range Mode. From what I read in the manual, what Range Mode is stated to do is only to limit HVAC power consumption, nothing else. But there are posts that suggest it does other things. Hard to know what is accurate and what is speculation or "folklore."

 

[isjka]

Yesterday I had the HPWC installed in my garage. I'm very impressed with the unit. Given my daily commute is only 6 miles one way, it's winter time, and the car sits out in the cold for 12+ hours, what is the best charging schedule I can implement? Is it best to always leave the house with 90% daily, or can I let the battery go down to 40%, 50% before charging it. Is there a threshold I should follow? Obviously I want to maximize the battery life span. I'm just not sure what pattern I should get into. I know leaving the house with a warm battery helps, but if I only need to charge for like 30 minutes or so daily, does the battery even get warm enough? I'm charging it on the 60 amp circuit.

Thanks.

 

[Big Earl]

There seems to be a lot of confusion about range mode.
This post says it heats the battery to a higher temperature.
What does Range Mode? | Tesla

Agree!!!

You're misunderstanding the operation.

In the summer time, range mode allows the battery temperature to be higher than it normally would be with range mode off. There are two reasons for this. 1.) Less energy is required to keep the battery cool. 2.) The higher operating temperature makes the battery more efficient. Having range mode on does not actively heat the battery to get it to that higher temperature ("maximum battery power" on Ludicrous cars does actively heat the battery up to about 50°C).

In the winter time with range mode off, the battery's target temperature is about 8°C, which is enough heat for the battery to accept about 30 kW of regen/charge. With range mode off, the battery's target temperature is significantly lower. It will only run the battery heater to prevent the electrolyte from freezing and causing battery damage.

 

[David29]

In the winter time with range mode off, the battery's target temperature is about 8°C, which is enough heat for the battery to accept about 30 kW of regen/charge. With range mode off, the battery's target temperature is significantly lower. It will only run the battery heater to prevent the electrolyte from freezing and causing battery damage.

I assume one of the two bolded words should be "on" instead of "off." My guess is, you meant to say "on" in the second instance, right?

I don't mean to be picky, just trying to be clear.

 

[David29]

Yesterday I had the HPWC installed in my garage. I'm very impressed with the unit. Given my daily commute is only 6 miles one way, it's winter time, and the car sits out in the cold for 12+ hours, what is the best charging schedule I can implement? Is it best to always leave the house with 90% daily, or can I let the battery go down to 40%, 50% before charging it. Is there a threshold I should follow? Obviously I want to maximize the battery life span. I'm just not sure what pattern I should get into. I know leaving the house with a warm battery helps, but if I only need to charge for like 30 minutes or so daily, does the battery even get warm enough? I'm charging it on the 60 amp circuit.

Thanks.

I think the consensus is that you should not charge to 90% or more unless you are about to depart on a long trip.
From my reading of lots of posts on this topic, with many differences of opinion, my conclusion is that charging to 60 or maybe 70% each night would be good in a case like yours. You won't need that much for 12 miles per day, but you will use extra energy for the cold weather, to heat the battery and the cabin. But do plug in every night, and do preheat the car for at least 30 minutes before leaving in the morning in the cold weather (and in hot summer weather, too). Try to schedule the charging so that it ends about when you plan to start the preheating. That way, the charging process will help warm the battery, but the preheating won't compete with charging for the current available from the charging circuit. On really cold days, you may find it worthwhile to charge for an hour, to help warm the battery if not for your own comfort. (I hear Chicago can get very cold in winter!)
The other possibility to keep in mind is that you might have other trips besides the daily commute, perhaps unexpectedly, so charge enough so that an extra trip won't be difficult or cause range anxiety.

 

[Big Earl]

I assume one of the two bolded words should be "on" instead of "off." My guess is, you meant to say "on" in the second instance, right?

I don't mean to be picky, just trying to be clear.

You’re right. The second instance should be on.

With range mode on, the battery’s target temperature is significantly lower.

 

[mspohr]

Yesterday I had the HPWC installed in my garage. I'm very impressed with the unit. Given my daily commute is only 6 miles one way, it's winter time, and the car sits out in the cold for 12+ hours, what is the best charging schedule I can implement? Is it best to always leave the house with 90% daily, or can I let the battery go down to 40%, 50% before charging it. Is there a threshold I should follow? Obviously I want to maximize the battery life span. I'm just not sure what pattern I should get into. I know leaving the house with a warm battery helps, but if I only need to charge for like 30 minutes or so daily, does the battery even get warm enough? I'm charging it on the 60 amp circuit.

Thanks.

With your short distance commute, I wouldn't really worry much about charging the battery.
I'd charge to 80% whenever the battery falls below 40% and you should be good even in cold weather.
I wouldn't worry about warming the battery. You'll have plenty or range regardless of battery temperature and your commute is so short that you won't be heating the battery much. No real point in heating the battery for such a short drive. Turn on the seat heater and climate to keep yourself warm.
The only downside of this is you won't have much regen in cold weather so you'll need to adjust your driving to compensate.
You only risk damage to the battery when it is charged to a high percentage (>90%) or drained near 0%.

 

[Brian-MS90D]

I agree with @mspohr. The main reason to preheat the battery is when you are going to depart on a long trip because you want to minimize using your battery range for things like heating the cabin and battery. Thus, you preheat the car while plugged in.

The Tesla battery is great and you don't need to worry at all if you keep the battery between 90% and 10% (generally speaking). Many on here will obsess with perfection and go on and on about how to MAXIMIZE your battery life by keeping the charge level at around 50% (or other schemes), but why? They are arguing over the infinitesimal. It's not like we're driving Nissan Leafs people! Enjoy your awesome car and battery technology (and its ability to keep you toasty warm in the winter).

 

[pilotSteve]

This thread is awesome! Good (sometimes excellent) technical insights, decorum and pleasant exchanges of ideas. Wow, it feels like Christmas spirit here at TMC! Nice.

 

[DarkMatter]

I'm in a similar situation as the OP - bought S75 just recently and live in a cold climate for winter, daily commute very short distance. I commute to the train station which is only 6.5 miles one way. My car at home is parked in a garage. I live in Chicago and for the past few days the temps in the morning have been near 20 degrees. My car sits unprotected at the station lot for at least 12 hours. Snow, wind, ice, etc. can all occur. Yesterday I "lost" 4 miles of range while the car sat there. I'm trying to determine the best plan of attack for the winter given I can charge at the station and also at home (I'm getting a HPWC installed on the weekend). My charging at home won't cost too much since I pay a variable rate, and in the winter, that rate is close .02/kwh in the overnight hours. Sometimes it's a penny or zero. And, I can park in the charging stall at the train all day since I have a permit.

Please consider not using the train station charging unless you absolutely need it. You pay an incredibly low rate for electricity at home. Leaving the station charger available may encourage someone else to acquire a PHEV or a short range BEV, and do more miles on electrons. Once you are set up to charge at home, you'll be driving for almost zero energy cost, and you'll get all the advantages of preheating from shore power.

 

[Big Earl]

Please consider not using the train station charging unless you absolutely need it. You pay an incredibly low rate for electricity at home. Leaving the station charger available may encourage someone else to acquire a PHEV or a short range BEV, and do more miles on electrons. Once you are set up to charge at home, you'll be driving for almost zero energy cost, and you'll get all the advantages of preheating from shore power.

Agreed. Some of our commuter rail stations have EV chargers and it's difficult to actually charge because the spots usually have PHEVs in them that are fully charged by late morning. One day I had to double-park behind two fully charged cars so that I could get to where I was going.

Of course, the chargers are there for commuters, so my passing through and needing a charge wasn't a priority. But - if you don't need them to complete your round trip, they should be left open for people who do need them.

 

[isjka]

Great feedback here guys. Some very useful data points here. Last night was the first time I charged the car with the HPWC. I set it to charge to 90% starting at 1:45 am so that by 5:30 am, I would be at 90%. Boy oh boy did I notice a huge difference. Not only did regen work right out of the garage, but I felt "safer" knowing I had close to a full battery. On top of that, the price of electricity was very cheap during the charging time (look at time ending 4:00 am which was less than a penny) In addition, according to my consumption, it looked like I used significantly way less power this morning than the past two days. It even dipped below 300 for a minute or two.

I'll take the advice of @David29 and maybe drop the charge to 70% or so. I also won't use the train station for charging since most people here agree that's not cool. The only reason I asked about charging at the station was to help avoid the drain I get when the car sits there idle for 12 hours. Yesterday, I "lost" 6 miles of range while it sat in the cold, if that is to be expected, I understand and can live with it. Like others have stated here, I just need to adjust my driving to account for no regen. And, as you can see from the pictures, in the cold, the car uses over 600 kwh. for such a short trip. I didn't want that process to hurt the longevity of the battery if that makes sense.

 

[Big Earl]

That's a great report! I'm glad the tips worked well for you, and thank you for following up.

Did you have range mode on or off when you charged?

 

[YauKwan]

gregtopf

are you selling your Tesla because of the cold soak issue?