Precondition Battery

[stromb0li]

Hey TMC,

I'm in the process of transferring ownership of my "new" used Model S to me and unfortunately don't have access to the mobile app for my phone (10 days into the transfer process with no update from them ). Living in a cold climate, is there anyway to precondition the battery without the phone/app? Luckily, I do have a heated garage, but I'm concerned leaving it outside for a few hours when traveling.

Similarly, is there a specific temp at which you should heat/precondition the vehicle up?

Last, I've seen many individuals recommend charging their vehicle every night. For winter, is it recommended to always stay near the 80% charge or can I drive a few days until it gets near the 20-30% charge mark and then begin charging again?

Thanks in advance for any tips or tricks!

 

[SSedan]

Preheating interior from the app will preheat the battery.
Keep it plugged in and recharge daily when possible but it is ok to skip a few days so long as you don't risk running out of juice.
What do you consider cold? Sitting outside with intermittent ise in say single digits weather is going to be g to be very hard on range. You will get a feel for it not preaching doom and gloom but if you see temps below freezing and particularly below zero expect daily energy use to spike dramatically. The longer the drive the less the impact of initial warmup.
I like near Green Bay with a 7 miles each way commute. In winter I can see energy use more than double due to a near constant state of warmup when driving, but on longer trips range is impacted less, hear to Eau Claire is no problem.
If you know you will be away from charging for a few days go to 90% or even time it for 100% just before leaving.

 

[P85_DA]

is there anyway to precondition the battery without the phone/ap

If the car is on your account yes u can use TeslaFi to precondition without having mobile app

 

[Tam]

...near the 20-30% charge mark and then begin charging again?

In any weather, generically, you should not wait to wear down the battery if you can charge before you get to a lower level.

That means: if you drive 10% a day, from 80% to 70%, keep the car plugged-in as much as you can and don't wait if you don't have to.

So it's better if you can charge at work from 75% to 80%, if not go back home and charge from 70% to 80% every day.

It's worse if you drive 10% a day and wait for 6 days from 80% to 20% then plug it in.

...specific temp at which you should heat/precondition the vehicle up?..

I have no experience with freezing Tesla winter but my understanding is:

There's no need to pre-heat if you know what it means:

1) Decreased regen brake until the battery is warmed up: That means you need to adjust your driving: lifting off the accelerator now wouldn't slow down the car while in impaired-regen mode.


2) Range is decreased when the battery is cold. It's not a problem if you charge your car at home at night.

However, if your Supercharger is 50 miles away and you are tired and want to sleep in your hotel because your car still has about 70 miles left which should easily cover 50 miles in summer.

But this is now sub-freezing winter and when you wake up in the morning, the battery is no longer warm so the gauge may say you have only 50 miles left.

The car might automatically turn its own heater on to warm its battery up and suddenly your gauge says you have only 30 miles left (because it costs lots of energy to warm up battery heater).

In that case, it is more prudent to drive to Supercharger first before sleeping in a hotel!

3) Slow supercharge: If your battery is cold, supercharge is super slow while it tries to warm your battery up. You might think it's broken and call Road Assistance but it's not, it's just very very slow!

...precondition the battery without the phone/app...

From your car, you can turn on "Smart Preconditioning" if you have saved your home and work locations.

 

[stromb0li]

In any weather, generically, you should not wait to wear down the battery if you can charge before you get to a lower level.

That means: if you drive 10% a day, from 80% to 70%, keep the car plugged-in as much as you can and don't wait if you don't have to.

So it's better if you can charge at work from 75% to 80%, if not go back home and charge from 70% to 80% every day.

It's worse if you drive 10% a day and wait for 6 days from 80% to 20% then plug it in.



I have no experience with freezing Tesla winter but my understanding is:

There's no need to pre-heat if you know what it means:

1) Decreased regen brake until the battery is warmed up: That means you need to adjust your driving: lifting off the accelerator now wouldn't slow down the car while in impaired-regen mode.


2) Range is decreased when the battery is cold. It's not a problem if you charge your car at home at night.

However, if your Supercharger is 50 miles away and you are tired and want to sleep in your hotel because your car still has about 70 miles left which should easily cover 50 miles in summer.

But this is now sub-freezing winter and when you wake up in the morning, the battery is no longer warm so the gauge may say you have only 50 miles left.

The car might automatically turn its own heater on to warm its battery up and suddenly your gauge says you have only 30 miles left (because it costs lots of energy to warm up battery heater).

In that case, it is more prudent to drive to Supercharger first before sleeping in a hotel!

3) Slow supercharge: If your battery is cold, supercharge is super slow while it tries to warm your battery up. You might think it's broken and call Road Assistance but it's not, it's just very very slow!



From your car, you can turn on "Smart Preconditioning" if you have saved your home and work locations.

This is fantastic advice! Really appreciate it!

 

[xyeahtony]

Preconditioning is only really useful for subzero temperatures.

I highly doubt you live anywhere where the weather requires preconditioning yet, and by the time you do hopefully app access will be granted.

 

[jeffpaul]

Preconditioning is only really useful for subzero temperatures.

I highly doubt you live anywhere where the weather requires preconditioning yet, and by the time you do hopefully app access will be granted.

It's been getting down to the 40's (F) up here in PA at night and if I drive to work in the morning without preconditioning, I have reduced regen and increased energy usage, double whammy. So, even in above zero temps it can be helpful.

I don't blame you for not noticing this in your location though

 

[SSedan]

Preconditioning is only really useful for subzero temperatures.

I highly doubt you live anywhere where the weather requires preconditioning yet, and by the time you do hopefully app access will be granted.

Preconditioning is as noted above useful above freezing even not just sub-zero.

Also consider a rechargeable battery has a limited number of usable cycles in it's life, any energy we can use off of wall power is reduced cycling of the pack, this is I believe the reason Tesla says to keep them plugged in.

Last year when it first got cold I learned suddenly the extra planning and challenges of owning a Tesla in a cold climate, too many folks here are dismissive of the impact it has. Not saying it is bad, there are pros like INSTANT heat and defrost.

 

[stromb0li]

I highly doubt you live anywhere where the weather requires preconditioning yet, and by the time you do hopefully app access will be granted.

It's getting to upper 20s at night and lower 40s for a high... Unfortunately, it won't be uncommon to hit -20F, with extemes around -50F around February since I live in what many would consider the 9th layer of hell

 

[SSedan]

I don't remember if I saw a full 20below with mine but certainly spent time in the teens below. I got thru winter with a 30amp 240volt outlet but since installed a wall connector. For this extreme cold I would consider 40amps to be minimum charge rate.
On the 30amp outlet when I set the car to warm up it could consume a few miles even while plugged in. and warmup before charging could take awhile. I began charging soon as I got home while it was warm from driving and would set warmup 20minutes or so before I was leaving for work.

 

[Zooomer]

Use the scheduled charging to start charging the battery to reach set level upon leaving. Charging warms the battery a lot. So if you can charge 10KW and need to add 20%, schedule to start charging 2 hrs before leaving and the battery/car will be warm.
This is better for the battery too (assuming you charge higher than 80%. Batteries degen sitting at HSOC.

 

[SSedan]

If in a heated garage I can see scheduled charging working, mine is often even outside and the garage is as good as outside, with variable temps scheduled charging was wildly inconsistent, Depending on temp and daily mileage I would either find the battery cold again or still charging, never seemed to hit close to right. I have a 80amp connection instead of 24amps this year though so I may try again.

I do think the charging when I got home was an adaptation to marginal charging amperage.

Those with more than one winter under your belt and a wall connector does the extra amperage warm the battery to a higher temp or speed warmup by allowing charging to begin while still warming?

 

[xyeahtony]

Preconditioning is as noted above useful above freezing even not just sub-zero.

Also consider a rechargeable battery has a limited number of usable cycles in it's life, any energy we can use off of wall power is reduced cycling of the pack, this is I believe the reason Tesla says to keep them plugged in.

Last year when it first got cold I learned suddenly the extra planning and challenges of owning a Tesla in a cold climate, too many folks here are dismissive of the impact it has. Not saying it is bad, there are pros like INSTANT heat and defrost.

From what i've seen, even if you precondition your battery you only get 30kw regen anyways. At what temperature does regen get restricted below that?

 

[SSedan]

Preconditioning warms the interior mitigating the initial conditioning energy use. Any energy you can use from the wall is reduced pack cycling.

I don't have any way of monitoring pack temp and outside temp is not the same as pack temp. That said the car hasn't moved in a few days and it is low 40s and raining now so typically this would lead to a regen limit. Vampire drain has drained it enough that I think it will top up at 4am, I will see what kind of limit I have.

You do bring up a good point about pack heating being shut off once 30kw regen is available. I wonder if charging at high amperage will generate enough heat to get me even more than 30kw on initial drive. Wont find out tomorrow morning since the top up is going to be so small.

Car is a 2014 with dual chargers I have been keeping it set at 42 amps so it uses both chargers at about half capacity, I might have to try cranking it up in cold weather to see if it does some extra warming.

 

[Zooomer]

When I charge for a few hours car will full regen on initial drive telling me the battery is warm

 

[SSedan]

When I charge for a few hours car will full regen on initial drive telling me the battery is warm

How many amps do you feed it and what temp is the car exposed to?

 

[WannabeOwner]

, is there anyway to precondition the battery without the phone/app?

I would suggest:

Charge the battery for an hour just before you are ready to leave. If temperature is cold that will bring on the battery heater - which will mitigate, but not eliminate, initial regen reduced-limit. i.e. you'll get full regen sooner [than if you hadn't done that preconditioning], and there's a good chance that it will also be less severe - e.g. if it is cold enough that the battery would otherwise becomes cold-soaked. That will require that you had not fully charged the car earlier - e.g. using schedule. So that may well mean that you have to charge to, say, 70% on schedule and then an hour before departure manually increase the max charge to, say, 90% (and manually start a charge [i.e. if the location is set to only charge at TOU off-peak period]) ... all of which may well be a nuisance ...

I would also increase cabin temperature before departure (10 -15 minutes probably enough), and without a scheduler such as TeslaFi or Phone APP the only way to do that is to get in the car, turn up the temperature, and on the Climate Menu use the override option that leaves Climate on after you exit the car. That too may well be a nuisance ...

If Phone APP not yet working then presumably 3rd party APPs won't work either ...but iIf you are going to try TeslaFi then a referral code will increase the trial from 2 weeks to a month. If you need one mine is WannabeOwner

 

[Zooomer]

How many amps do you feed it and what temp is the car exposed to?

I charge at home at 48 amps with wall charger. It's in a condo garage which is normally about 10 deg over ambient in the winter.
Anything under 52F or so the car will limit regen some. The colder, the more/longer. I normally set charge limit to 90 and use scheduled charge so that I hit 80-85% when I leave. If the car charges for a few hours, it's normally plenty to warm the battery/car.

If I'm traveling I use the max battery performance thing (P100d) to preheat the battery a lot to hold more charge and get me significantly more range.

 

[milleron]

One other thing to remember is that Range Mode disables the battery heater.
My garage is not heated but almost never goes below 40°, even when the outside temp is in the teens or single digits. At 40° with Range Mode off, I've never been able to see the battery actively heating for more than a few minutes after starting to charge an hour before leaving. The phone app shows battery heat immediately after initiating the charge, but it continues for only a few minutes. Even with an hour of charging at 48 amps, regen will still be significantly reduced when leaving home and may not reach normal even after 18 miles on the freeway. I sure wish Tesla would modify firmware to provide more battery warming on shore power OR provide an explanation of why that can't be done.

 

[SSedan]

They have decided battery warming is not needed beyond a certain threshold, that is all. Likely decided that Regen and driving are a more efficient use of energy to warm the pack beyond that.