Rapid Vampire Drain - 20km range lost in 3 hours!

[randvegeta]

I have a Model S 60. Today I was driving back home, starting with a around 205km (rated) range. My journey was only 140km and I figured I had plenty of range.

After 120km of fast driving in rainy 5 degree (celcius) weather, we arrived in our city (20km from home) with around 70km of range left. So we used around 135km of our rated range. We stopped to meet some friends and grab a bite to eat, leaving the car parked outside for around 3-4 hours.

When we got back to the car to head home, we only had 50km of range left. 20km seems to have magically disappeared. Luckily we only needed 20km of range, but even though I drove home slowly i relatively flat conditions, by the time we arrived back home we had consumed another 30km of range.

Okay there are many things that can affect actual range, but what the hell happened to that 20km of range in the 3 hours while parked? It's not like there was an extra 4kwh consumed, and yet it was no longer there.

Is it the cold weather perhaps? Would the warm battery show greater range and as the battery cooled over that 3-4 hours, there was less accessible energy, and therefore reducing available range?

Does this mean that Tesla's range estimates do actually take battery temperature into consideration?

It was very disconcerting. I'm only a new owner, so I haven't become accustom to these quirks yet. Is this normal? If yes, I need to plan better to ensure I have a sufficient buffer to reach the next charging point.

 

[jdw]

Rain and cold weather will use a significant amount of energy and, yes, a cold battery will not have the same range as a warm one.

At 5 degrees, sitting for a few hours and without range mode on, the car will also use a lot of power to try to warm the battery. Range mode is helpful in cold weather to reduce battery heating energy draw - particularly if you have a number of short trips to do.

A useful post on cold weather driving from Doug_G

 

[randvegeta]

Rain and cold weather will use a significant amount of energy and, yes, a cold battery will not have the same range as a warm one.

At 5 degrees, sitting for a few hours and without range mode on, the car will also use a lot of power to try to warm the battery. Range mode is helpful in cold weather to reduce battery heating energy draw - particularly if you have a number of short trips to do.

A useful post on cold weather driving from Doug_G

Interesting. But the battery doesnt try and stay warm if the car is just parked does it?

So you think the 20km lost may be simply because it was left cold for 3 hours? So that energy wasn't actually consumed... it was just inaccessible due to cold?

Is the opposite true? if you get into a cold car showing 100km of range, and then you put the same car in a heated garage, it would show more range after sitting in that heated garage for a few hours?

 

[scottm]

Did you pre-warm the car from the App before leaving? That would kill some range.
Next time, if you had plugg3d in for the visit at your friends, even at 120V you probably would have gained a bit instead of dropping.

 

[randvegeta]

Did you pre-warm the car from the App before leaving? That would kill some range.
Next time, if you had plugg3d in for the visit at your friends, even at 120V you probably would have gained a bit instead of dropping.

I havent got the app working yet so no. There shouldn't have been any pre-heating. I parked on the street in public, not at a friend's house so there was no where to charge to top-up.

Maybe the 20km range loss is normal?

 

[jdw]

Interesting. But the battery doesnt try and stay warm if the car is just parked does it?

So you think the 20km lost may be simply because it was left cold for 3 hours? So that energy wasn't actually consumed... it was just inaccessible due to cold?

Is the opposite true? if you get into a cold car showing 100km of range, and then you put the same car in a heated garage, it would show more range after sitting in that heated garage for a few hours?

In extreme cold with range mode off , the battery may use some energy warming itself, but normally no, it just shows as temporarily reduced range. The battery will show greater range at higher temperatures in general.