Taking delivery of my Model S today! (12/2/12)

Great data. 475 Wh/mi in Jan, wow.

Heat sucks up the most energy. Did you use A/C in the summer? It does not look much impact on Wh/mi.

 

Absolutely, sorry, I should have been more clear.
The Wh/mile and such are measured per the dash. The costs I calculate from our electric meter which measures only EV charging.

It had been about 4kWh/day which would be roughly 12 miles/day. It is now about 2-3 miles per day.

No, no changes were made to the battery management. The power use of constantly on systems were optimized. In addition there are multiple levels of 'sleep' that power down more and more systems. For example, if the car sits for a long enough, it will no longer automatically extend the door handles as you approach. You need to gently press the handle and then it will extend. This is somewhere over 24 hours I think.

Our experience with the 60 supports that. Although there are a number of things that may make that difference look larger than it is. 21 inch performance tires will cut into the efficiency. I am not sure what options were on the 60 and 85 or 85p that were tested.

The lower power limit on the 60 is likely the biggest contributor of the better efficiency. Weight contributes some as well as lighter, lower rolling resistance tires.

I should add, this winter we put on winter tires which lower the efficiency a bit. That and the colder weather are the contributors, I have been able to identify, to the efficiency loss.

 

Yes, all of our driving has used the heat and AC as appropriate. No special measures and no hypermiling (except on one trip where I was testing the range).

AC takes up such a small amount of power compared to heating we really haven't noticed it at all. Of course, I am in MN where 100 degree highs are rare.

 

Wow, that's more electricity than it takes to fully charge PiP.

So, if you only drive 12 miles a day, Model S would consume 8 kWh?

 

Incorrect tense, but yes. It used to be that if you drove 12 miles the Model S would use an average of 8 kWh over a 24 hour period. Now it would be closer to 5.
Of course, if you drive 200 miles the Model S would use an average of 67 kWh while the PiP would use 4 kWh pluse a few gallons of gas:wink:

If you typically drive 12 miles a day I have no idea why you would buy an EV that goes 20 times that distance (if conservation is your goal).

The LEAF and other smaller, shorter ranged EVs are more efficient than the larger Model S.

It is, as always, about the right tool for the right job.

 

Ok, but you only drive 52 miles per day, on average. I guess 2-3 miles vampire loss per day is acceptable. Does vampire loss differ through out different seasons?

The point was, the bigger the battery pack (more range), the higher vampire loss.

 

I don't think you understand what is generally defined as "vampire losses".

Vampire loss refers to the amount of electricity used while the car is off. This is caused by devices in the car that continue to use power when the car is off.

Examples could be a cell data connection that stays active, the process that 'listens' for the fob to be nearby if active (total guess, I don't know if this really uses any when off or how much), any other battery monitoring systems.

It makes no difference what size battery pack is in place for the amount of battery loss.
When they went from 4kWh to 1kWh vampire losses it wasn't because they shrunk the battery.

The size of the battery pack certainly affects efficiency of the vehicle as a larger pack will weigh more and the additional weight requires more energy to move.

To your first question, vampire draw is not affected by season. Or if it is, it is by a negligible amount.

Season definitely affects the efficiency of the car due to battery HVAC, cabin HVAC, and chemistry of the batteries. This is shown in my drive efficiency numbers.

Charging will also be less efficient in cold or hot weather as the battery management system heats or cools the battery pack so it is in a safe range when the car is charged. This is reflected, along with the lower car efficiency, in the cost per mile variation between summer and winter (2 to 4 cents).

 

I did not know Model S lacks the active thermal management of the battery pack. Roadster had it as it uses the A/C to cool down the pack, even when the car is off.

Does Model S include the vampire loss to report kWh consumption on the dash?

 

So, the monitors for the electricity consumption can distinguish between power going into the battery and what doesn't while plugged in? Worded another way, maintenance charging isn't calculated amoung the 'vampire losses'?

Presumably, the vampires are part of the reason you shouldn't leave a Tesla unplugged for any extended length of time.

 

It has it. It just appears the energy used for it is counted in the energy to charge a battery. For accounting it makes sense. It is energy expended to protect the battery and allow efficient charging. Likely the same for maintenance charging. If the energy required for thermal management seems low, the mass of a larger battery could hold its heat level longer than a smaller one.

The vampire losses are power drains that apparently have no function in charging or protecting the battery. Like the SKS in the Prius. It's a system that has nothing to do with the car's improved efficiency and emissions, and in the gen2 could kill the 12volt battery if the car was parked for extended periods.