Changes to umbilical function

[TrevTremaine]

I'm just noticing a difference in the "umbilical" functions between old and new Teslas. On my Model S, when the car is fully charged and I go to heat up the car, it'll draw power from the charger in order to keep the battery at a full charge. On my Model Y, even though it's on the charger it'll draw from the battery first, then recharge as the state of charge drops down a bit.

The situation with the Model Y could potentially shorten your effective range when you go to leave.

Is this something across the board, or solely on the 3/Y?

 

[Watts_Up]

Are you using the App Scan My Tesla to detect this behaviour?

You should review some recent YouTube video from Bjorn Nyland.

One difference between the S/X and 3/Y is the use of heater devices instead of using the motors to get some heat to warm the habitacle and the battery.

For the 3/Y if you only want to heat the habitacle use the Camp Mode, but this is not available using the remote.

If you want to warm only the battery use the Heating Control, but keep the habitacle temperature at the current ambient temperature.

 

[TrevTremaine]

Are you using the App Scan My Tesla to detect this behaviour?

You should review some recent YouTube video from Bjorn Nyland.

One difference between the S/X and 3/Y is the use of heater devices instead of using the motors to get some heat to warm the habitacle and the battery.

For the 3/Y if you only want to heat the habitacle use the Camp Mode, but this is not available using the remote.

If you want to warm only the battery use the Heating Control, but keep the habitacle temperature at the current ambient temperature.

No, I'm not using an app to detect it - it's obvious from observation. While I understand the different methodologies of heating implementation, its the functional differences that are interesting to note. In essence, while one will draw power directly from the charger to heat and prep the car, the other uses the battery to do it then will charge the battery once the level of charge has depleted a bit. Why do I ask? Simple. If you're concerned with the number of cycles a battery can recharge, then the situation with the 3/Y will exacerbate it. In the older cars, it bypasses the batteries entirely and preserves the state of charge as well as reduces the number of charging cycles the battery endures.

 

[rypalmer]

In the older cars, it bypasses the batteries entirely

This is not quite accurate to say - I think it's more correct to say that on older cars, with full batteries, the charging input was regulated to cancel out the load on the HV battery from the PTC heater or other onboard equipment. So hopefully it's as simple as a software fix for newer cars.

 

[Watts_Up]

No, I'm not using an app to detect it - it's obvious from observation.
While I understand the different methodologies of heating implementation,
its the functional differences that are interesting to note.

In essence, while one will draw power directly from the charger to heat and prep the car,
the other uses the battery to do it then will charge the battery once the level of charge has depleted a bit.
Why do I ask? Simple. If you're concerned with the number of cycles a battery can recharge,
then the situation with the 3/Y will exacerbate it.

In the older cars, it bypasses the batteries entirely and preserves the state of charge
as well as reduces the number of charging cycles the battery endures.

I noticed in Canada that cars have an electrical plug connected to a resistive heater
located in the oil pan to keep the oil warm overnight.

When an EV is connected to an L2 plug, it would be very simple and not very expensive to have a resistive heater
keeping the battery warm instead of using the energy stored in the battery to keep the battery warm.
This could both save energy and increase battery life.

Adding a resistive heater could be an option for cars, sold in countries with harsh weather conditions,
whose battery capacity and longevity are already badly affected by the cold weather.

 

[TrevTremaine]

I noticed in Canada that cars have an electrical plug connected to a resistive heater
located in the oil pan to keep the oil warm overnight.

When an EV is connected to an L2 plug, it would be very simple and not very expensive to have a resistive heater
keeping the battery warm instead of using the energy stored in the battery to keep the battery warm.
This could both save energy and increase battery life.

Adding a resistive heater could be an option for cars, sold in countries with harsh weather conditions,
whose battery capacity and longevity are already badly affected by the cold weather.

Well, if the old one already had resistive heaters, does the new one automatically mean that the resistive heaters are gone completely or supplemented with the heat pump? I'm noticing that as the temperature drops right now, the Y consumes a lot more energy than when it was warmer. I'm not going to get into a full analysis, but based on what I'm seeing I don't see the supposed winter time improvements being as dramatic as suggested.

 

[rypalmer]

When an EV is connected to an L2 plug, it would be very simple and not very expensive to have a resistive heater keeping the battery warm instead of using the energy stored in the battery to keep the battery warm.

Perhaps, but its current drawn would have to be deducted from the available current the onboard charger can draw. And it would only provide inefficient resistant heat. I think it's a better plan just to account for this in the use of existing heat sources and the onboard charger, which already has the ability to throttle its output based on J1772 signalling.