the Tesla battery pack heater well what does it do well as the name suggests it
heats the battery pack but why well two main reasons number one if lithium gets
down to a cold enough temperature it can be damaged or lithium batteries not the
metal itself and number two lithium elites the chemistry inside the Tesla
Model S X and three do not like to be charged at far below freezing as such
the battery pack warmer heats the pack up to a safe temperature to allow
charging and charging means actually plugging it in and also region this is
why if it's very cold out you might not have regen when you first get in your
car and it's been sitting singing overnight now the battery pack heater
uses a considerable amount of power it usually kicked in when you get in your
car or plug it in and the pack temperature is at or below freezing and
brings it up to a necessary temperature usually shuts off at around forty five
degrees Fahrenheit roughly I think that's seven point five degrees Celsius
roughly approximate and of course freezing would be zero Celsius
now in terms of using the battery pack heater to gain your region back personal
opinion it's not worth it why because the amount of power it consumes is going
to use more power than it would if you just used your friction brakes in the
car as such we have this nice feature on our model our Tesla vehicles called
range mode it does a couple of different things and it varies depending on which
type of Model S xr3 you have and features such as two wheel drive or
four-wheel drive but one big thing it does is it reduces the temperature that
the battery pack heater will turn on in most cases so if you turn on range mode
instead of that battery pack heater turning on at 32 degrees Fahrenheit or
zero degrees Celsius it won't turn on until about negative 5 to negative 10
degrees Fahrenheit hey Siri negative 10 degrees Fahrenheit to Celsius or
negative twenty three point three degrees Celsius
now that's Tesla's hard-coded cutoff limit we're below that they don't want
the vehicle to not heat the battery pack now if the vehicle is parked not
charging and just just parked that heater it's and this is a misconception
that heater is not going to turn on unless the battery pack gets to the
danger levels that Tesla has hard-coded now if you're not plugged in that
battery pack here will draw power from the natural traction pack and if you are
plugged in but not charging it will draw that power from the wall or the grid now
that is why Tesla says do not leave your vehicle unplugged in temperatures of
negative 20 degrees Fahrenheit or colder for periods of exceeding 24 hours
and me Hyneman is if it's a charged up battery pack and within 24 hours of it
keeping and this is self-preservation mode pretty much here that battery pack
is going to be dead and it will no longer be able to maintain the proper
temperatures to keep damage from happening to your traction pack now
anything can help and it could be as simple as a hundred and twenty Volt
15-amp outlet you're not probably at those temperatures you're probably not
going to gain any range but you're also not going to really lose too much and at
the very worst you might lose a little bit but the car will be able to pretty
much maintain its systems indefinitely as long as there's shore power even on
that 15-amp outlet consider it this way for every two minutes of power drawn
from a 15 amp 120 volt outlet that gives the car enough power to heat the battery
pack for one minute and it's not going to be continuous once the pack reaches a
safe temperature the pack heater will shut off and they'll continue to
hopefully charge the battery then and as it's needed turns on/off on/off just
like when you're heating your house and your furnace will turn on and off on and
off to keep the temperature set as required now another way to keep your
battery pack warm is the actual act of charging it so if yours is like mine and
plugged in outdoors in a driveway most of the time they're parked outside in
the driveway most of the time at night do these charging what you can do is
adjust the average of your charging so that way the the charging completes
shortly before you need to use your vehicle the next day
benefit of this number one you will have your full region right away when you're
driving without having to worry about the battery pack heater needing to keep
the battery pack to give your region and act of charging alone should provide in
most situations except the absolute most coats off your northern canada or alaska
you might have a little bit of issue there but in general it will provide
enough heat just from charging the battery to be able to keep the pack warm
enough to provide you at least some sort of regen windchill will be the the
quickest thing to cold plus the windchill will give me the quickest
thing to reduce that pack temperature so even if you have an unheated garage that
you could park in you're gonna be so far ahead in terms of how warm your pack
will stay then if you're parked outside now
just in terms of the car maintaining itself until it hits that magic
temperature where Tesla has determined yeah that's it which is probably gonna
be around I can't give you an exact number because we don't get those kind
of temperatures here in Wisconsin and if we do it's only for a few hours
overnight and by morning the Sun come enough that temperature is raising
anyways but I'd have to say it's gonna be right around negative 20 degrees
Fahrenheit hey Siri negative 20 degrees Fahrenheit to Celsius negative twenty
eight point nine degrees Celsius so since that's what Tesla States not to
leave your carpet unplugged in for more than 24 hours we'll say around negative
20 degrees Fahrenheit that's the only time in general that the pack will
heater will kick in when the car is not charging or not in operation so say your
car's plugged in outside overnight and charging completes within one hour so at
that point the car's not charging it's also not being used it's not gonna heat
the battery pack so you're not wasting power heating a battery pack it's not
like an internal combustion engines block heater or that suckers running all
night just to keep that block that that block warm so it starts to the next day
it doesn't work quite like that common misconception so it's not that you're
wasting power it's just that it's not being used and it only will kick in
again then once again if you have range mode off when you get in the next day so
you can start having your region now also not warming up the battery pack
not only provides you slower charging or no charging at all or / no region at all
you might also have lower power output when driving so if you watched my video
a couple days ago about I plugged in with a absolutely frozen battery pack
you can see my my energy graph and I had I was limited to about 75 kilowatt of
acceleration drawing a lot of power at colder temperatures there's also a lot
more resistance in the batteries and that resistance will prevent you from
being able to efficiently draw a lot of power out of them and which is why test
limits out the output net out for that output limit also limits the amount of
stress placed on those cells so I hope that answered some questions now if you
do have a little bit of regen now even if you have range mode on when you plug
the car in the car takes over everything battery management system controls
everything you have no way to disable that pack heater it's gonna draw Shore
power once you're plugged in - until it can start charging the battery and it
hits that magic limit around 45 degrees Fahrenheit and despite belief it does
not bring the battery pack up to full pop temperature it just gives you enough
so you get some region you can do your charging now with superchargers the
supercharger alone once that starts charging it it's able to dump so much
current and so much power and energy into your battery pack that it really
won't need the heater in the entire time it will once the heater shuts off just
the act of that charging is also going to continue to bring the temperature of
the pack up and you'll notice then as a pack warms the charging current from the
supercharger will go up and pretty much it's only a supercharger is going to be
able to output enough power or it will be limited on a colder
pack once the battery pack heater shuts off and I know I've seen some variations
over the versions my 90 D draws about 3 to 3.5 kilowatt for the battery pack
heater and on my old M s60 from 2013 I actually noticed it draw at one point at
least it appeared to approximately 6 kilowatt although it was a couple of
versions ago they might have found that they don't really need that much power
for charging or warming the battery pack so I hope you learned just a little bit
here if you want me to clarify something else or a little more please post in the
description box below and don't forget like and subscribe and stay tuned