Advice: Headed to mountains, no garage

[Lhshockey24]

We will be taking the S 100D to a cabin in Tahoe this January. Most nights are between 10-20*F. I understand it’s best when really cold to leave the car plugged in overnight so the battery can manage its temperature better. Will the people whose cabin I’m using see a huge spike in their electric bill during these nights? I don’t want to charge, there’s a supercharger nearby, but just stay plugged in to keep the battery from getting too cold.

Any other advice on a trip like this, staying in a rental cabin and driving a few miles around town each day, would be helpful. Thanks!

 

[Tam]

...I don’t want to charge...

As long as you've got more than enough range, I don't think you need to plug in if you don't want to cause an electrical expense to your host.

If you do plug in, I think the car would use shore power first if it needs to warm up its battery.

Thus, when battery gauge says 80% remains, and you set charging limit way below that at 50%,..., the car won't charge but when it needs to to warm up its battery, it doesn't use the energy from the battery first because you are now plugged in which will incur expenses to your host.

Let's calculate your consumption so you can pay your host:

120V x 12A then your car would consume 1,400 watts or 1.4 kiloWatts which is about the same as a hot electric iron for your clothes.

PG&E rate is about 17 cents to 40 cents for each kiloWatts.

Let's use the highest rate to compensate your host.

If your battery heater runs 8 hours then:

1.4 kiloWatts x $0.40 x 8 hours = $4.48 total!


If you use 240V then just use the same formula to figure out the cost.

 

[Evoforce]

Your car uses a very little amount of electricity especially to just maintain it's temps. This should be of zero concern. At our home, we charge two electrics every night at EV .04 cents a KW rate and it costs less than $50-$60 a month total for all night time house loads and charging two cars to 90%.

Tesla has a range chart and how much it will cost to charge that is available on their new car buying website. Click on Model S and scroll down to Charging Estimator. Plus, if you lose (for example)10 miles of range because of maintaining, it is also easy to figure it using their new car buying Charging Estimator. Using 10 miles as an example would equal 40 cents.

 

[Tam]

By the way, you should plan to Supercharge while the battery is still warm. That means Supercharge at the last station before give your car a rest.

If go to sleep first then charge it in the morning and if the battery is now cold (the battery heater has its own mind and it only turns on by itself if it wants to), it would take a very long, long time to Supercharge.

If that's the case, pre-warm your car with your phone app when you wake up in the morning to hope that it would wake up the battery heater to keep the battery warm for Supercharger.

 

[Lhshockey24]

By the way, you should plan to Supercharge while the battery is still warm. That means Supercharge at the last station before give your car a rest.

If go to sleep first then charge it in the morning and if the battery is now cold (the battery heater has its own mind and it only turns on by itself if it wants to), it would take a very long, long time to Supercharge.

If that's the case, pre-warm your car with your phone app when you wake up in the morning to hope that it would wake up the battery heater to keep the battery warm for Supercharger.

I remember reading this elsewhere so we plan on charging on the way up and then I’ll precondition the car before heading down the hill for a supercharge on our way out. Thanks for verifying this again!

 

[Rocky_H]

Most nights are between 10-20*F. I understand it’s best when really cold to leave the car plugged in overnight so the battery can manage its temperature better.

That's not even close to the range of what is too cold. Look through the manual, and you'll see that the warning is related to if the car is going to be in -22F temperatures for more than 24 hours at a time. Above 0F like you're talking about isn't any concern.