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Lex
Member
But yes to coolant running through the motor shaft, no ? It's one of Tesla's patents... though I wonder how much it actually affects the coolant temp.
This is a big disappointment for me. I have had Range Mode enabled since delivery 3 years ago. I had no idea it affected battery temperature management at the high end. I am now at almost 40,000 miles and the degradation appears to be around 6%. I really wish Tesla documented their features better so customers can make appropriate decisions.
While I agree 6% is a lot I doubt very much that having Range Mode on caused any problems to your battery. My guess is you need to balance/calibrate to see what you really have in Rated Range.
Lex
Member
Yes, I was curious about just how much the coolant mass is affected by this part of the system and my guess is "not really enough to help warm the pack enough to matter much" but instead "plenty enough to help the motors last longer than 25,000 miles each."
Pretty much exactly the same amount removed from the motor/inverter goes into the battery pack. 30kW cruise with 95% (for example) efficiency? That 3*.05=1.5kW of excess heat going into the pack. Of course the efficiency is not fixed, I'm sure it's well under 95%, for example under hard acceleration.
Better avoid "Max battery power" then... I suppose that also causes degradation without Tesla warning owners?
There are PLENTY of Leaf owners, myself included, who would love to have 6% degradation after 3 yrs!
Bankroetlama
Member
Are these your personal assumptions or proven facts? Does Tesla heat up the battery, or simple stops with cooling it.
I think the general observation is that it doesn't cool it as much. But i could be wrong.
Bankroetlama
Member
It is a very important distinction!
If Tesla heats the battery, it would mean a warmer battery is better.
If they stop cooling the battery, it means that a warmer battery is worse, but that they don't want to use extra energy too cool it in range mode.
If Tesla heats the battery, it would mean a warmer battery is better.
If they stop cooling the battery, it means that a warmer battery is worse, but that they don't want to use extra energy too cool it in range mode.
Most Li-Ion batteries are happiest at 20C (68F). If temperature goes much above or below that, it can affect performance and even damage the batteries if the stress goes on too long. They can't keep them that cool most of the time without some kind of refrigerant, but with range mode off the system does as much as it can to regulate the temperature.
In the winter selecting range mode reduces the amount of pack heating by quite a lot. The heaters don't come on unless needed to protect the battery. It's easy to see this behaviour as you can start one morning in range mode and one without range mode and watch what the Wh/mil do. In summer it's harder to see what happens, but I suspect it's the inverse of winter. e.g. the battery is allowed to get to the maximum allowable temperature before the compressor is turned on. In summer I've never found range mode to do all that much, so I don't bother with it.
Lex
Member
But for those of us with D model it seems to do more with the front motor... only adding to the votes for "sure wish we knew exactly what these buttons do".
And yes I know it says torque sleep or some other specifics is in the manual or guides or on screen etc.
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