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Warming the Battery
- Thread starter Tonyz
- Start date
There is no function to "keep the battery warm" when plugged. You can either plan you charging so that it starts a bit before you leave (scheduled charging or scheduled departure) or you start the cabin heating some time before you leave. Charging will warm the battery in itself, and the car will heat the batteries before charging if they are too cold. heating the cabin also preconditions the battery up to ~20C. If during the heating your car falls below your set charge %, it will start charging if it's plugged in.
A post like this is a pretty sure sign that someone has "gone down the battery care rabbit hole". As @GtiMart says, this is something the car will do, or not do, as it needs to. Whether you have the car plugged in or not will not change the ultimate amount of power used. Either the car will "do what it needs to do (if anything at all) while plugged in, or if not plugged in, it will also "do what it needs to do" and possibly use more power (that would then be replenished the next time you charge).
TL ; DR - the car manages all that, and nothing you do will change how much effectively you pay for it. Plugging in and trying to "warm the battery" would be about winter range, not about cost of electricity.
TL ; DR - the car manages all that, and nothing you do will change how much effectively you pay for it. Plugging in and trying to "warm the battery" would be about winter range, not about cost of electricity.
Thanks for the info. I know there is an approximate number of charging cycles for a mo 3 l/r battery and I believe its 15,000. If you plug in each night in the winter (3 months), does each night count as a changing cycle? I only drive 50 miles round trip to work but have read the car should be plugged in each night in the winter. Sorry for all the questions.
when there are talks of number of cycles of a battery for lifetime calculation, it means a full 100-0% usage. Charging every day will not hurt. On the contrary, shallow discharge/charge cycles have been proven (in general, not specifically to the model 3 battery) to be better for battery health.
As jjrandorin says, you've gone down the battery rabbit hole. Don't worry so much about it.
As jjrandorin says, you've gone down the battery rabbit hole. Don't worry so much about it.
Tam
Well-Known Member
I agree with above answers.
Short answer for your question is "no" because the long answer is most people don't use one charging cycle per day.
A charging cycle is from 100% full to 0% empty but I hope you don't do that because those extremes shorten its longevity.
Thus, the below are all 1 charging cycle: You can add partial cycles to become 1 charging cycle.
1 x 100% to 0%
2 x 90% to 40%
4 x 90% to 65%
10 x 90% to 80%
Deeper discharges are not good. If you monitor your plugged in Model 3 and when it's all completed at 90%, you would see it trickle charge like from 90% to 90% (those are not actual 2 same 90%= one is the real 90%, the other is a fraction less than 90% but the battery gauge would round it up as 90%) and it doesn't wait for a deeper discharge like from 90% to 97% to start the trickle charge.
Since you use 50 miles per day, it's better to plug it in every night and don't wait till you drove 5 days x 50 miles = 250 miles to plug it in.
This is a helpful post. I get what you are saying about the battery rabbit hole, but I think it is a bit more important to understand how this works based on where you live. For example, I live in Minneapolis,MN and my garage is attached but unheated. It will get and stay below freezing in the garage multiple days per year. Coldest I've seen is 2F degrees. So in my case, I would expect it will be important to use the scheduled departure and preconditioning or my range may be limited. And I'm guessing I will use more energy just to get the battery up to a temperature where it will charge. Still waiting on the car.
Remember that the lower battery range will come back as it warms up, so even if you hop in a non-preconditioned car aside from the energy taken warming the cabin, you won't really see decreased range.
As far as "using more energy to get to a temperature where it will charge", just plug in when you get home and the battery will already been in the charging-zone and stay there because it is actually charging. If you then want to precondition the car in the morning, that's up to you. Note that the these cars take only tens of seconds before meaningful heat output(although on the new heat pump models that's probably slower unless they have resistive heat as an instant solution). For either heating or cooling, open the app and turn on the HVAC before you start walking to your car, and it'll be a fine temperature by the time you get there.
Just took delivery on a M3 LR and I have a basic question. I understand about scheduling charging, but do folks leave the car plugged in even after the car hits the set charging limit if the car is not going to be used for a bit. I thought I read in the manual that Tesla recommends that the car remain plugged in even if the car is not in use.
No, a battery cycle in the way you are talking about is one full drain of the battery from 100-0. If you only used 10% of your battery every day (as an example) it would take 10 days to = 1 battery cycle.
Tesla recommends plugging the car in every day, but thats mostly so people dont come back and say ""omg I forgot to plug in last night and i dont have enough range to XXXX ... ahhhhhhh!!!!!".
I keep mine plugged in when I am at home, several long time owners (much much longer than me, who have only had a tesla since 2018) do not. If you CAN plug it in at night, there isnt any reason at all not to, but if you cant or dont want to, its not that big a deal either, especially with a 50 mile a day commute.
At worst, that 50 mile a day commute could take 100 "tesla miles" off your range , but if you plug in every night it simply will not matter.
Candleflame
Active Member
The cold is actually good for battery longevity. What is bad is if the battery gets charged (bad) or discharged (worse) when its cold.
These things dont matter if you have the car plugged in into an outlet which can provide 4 to 5kw. You can just preheat the battery 20 to 15 min before you go.
These things dont matter if you have the car plugged in into an outlet which can provide 4 to 5kw. You can just preheat the battery 20 to 15 min before you go.
A frozen battery is a bad thing - thus, when the battery gets close, the car will wake up and automatically heat it.
A cold battery is an inconvenient thing - regen will be limited, performance will be limited, etc. People who live in Cold climates like MN have various techniques to warm up the battery before they leave in the morning - for example, using the Scheduled Departure feature will start charging such that the car is done just about the time you're ready to leave in the morning, thus the battery will be warm and everything will be good.
Heating the battery takes a bit of power - but it costs me only about $6 to put 300 miles worth of charge in my car. Adding $0.25 to heat the battery (which, by the way, isn't something I ever need to do...) would be a no-brainer.
There is no problem with leaving the car plugged in. Your car has the worlds most intelligent charger; it'll charge up to the level that you set, and stop charging. This isn't like battery operated tools from the 1990's, where leaving it plugged in for weeks would cause permanent battery damage. For a Tesla, you could leave it plugged in for years and it would be happy the whole time.
The cycle life for a Lithium-Ion battery, as others have noted, is based on a 100->0->100% charge cycle, and is normally given as the point where the battery is only capable of 80% of the capacity it had when it was new. 1000 cycles is a fairly normal specification for LiIon batteries - if you assume that a 100-0-100 cycle represents 310 miles (my 2018 LR RWD rated range), that's 310*1000 = 310,000 miles of travel. And at that point, the batteries should still be good, but you may only have (310*80%)=250 miles of range. Not really something to worry about, unless you routinely drive 100,000 miles a year...
A cold battery is an inconvenient thing - regen will be limited, performance will be limited, etc. People who live in Cold climates like MN have various techniques to warm up the battery before they leave in the morning - for example, using the Scheduled Departure feature will start charging such that the car is done just about the time you're ready to leave in the morning, thus the battery will be warm and everything will be good.
Heating the battery takes a bit of power - but it costs me only about $6 to put 300 miles worth of charge in my car. Adding $0.25 to heat the battery (which, by the way, isn't something I ever need to do...) would be a no-brainer.
There is no problem with leaving the car plugged in. Your car has the worlds most intelligent charger; it'll charge up to the level that you set, and stop charging. This isn't like battery operated tools from the 1990's, where leaving it plugged in for weeks would cause permanent battery damage. For a Tesla, you could leave it plugged in for years and it would be happy the whole time.
The cycle life for a Lithium-Ion battery, as others have noted, is based on a 100->0->100% charge cycle, and is normally given as the point where the battery is only capable of 80% of the capacity it had when it was new. 1000 cycles is a fairly normal specification for LiIon batteries - if you assume that a 100-0-100 cycle represents 310 miles (my 2018 LR RWD rated range), that's 310*1000 = 310,000 miles of travel. And at that point, the batteries should still be good, but you may only have (310*80%)=250 miles of range. Not really something to worry about, unless you routinely drive 100,000 miles a year...
Candleflame
Active Member
Unfortunatrly that is not true as over 10% degradation is completely normal after 15k miles.
Sadly for much of the country, we don't have some of the lowest electricity rates in the US. In MA, our electricity costs are triple those of AZ.
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