Electric cars and cooling drag

[aerohead]

I reverse-engineered the values from the numbers you provided in your book. Some, who may choose to play around with these sorts of things will have a higher degree of resolution with the given decimal places.
I'd rather fail on the side of anal retentiveness, than publish so gross values, that they're of little value to users. 4- place accuracy is seen across the literature. Five doesn't hurt anything. Bankers take it out to 13- decimal places every day.

[aerohead]

Well, I won't bother you anymore with facts, and just leave you to go down in flames on your own. Pitiful. Just pitiful.

[JulianEdgar]

Originally Posted by aerohead

I reverse-engineered the values from the numbers you provided in your book. Some, who may choose to play around with these sorts of things will have a higher degree of resolution with the given decimal places.
I'd rather fail on the side of anal retentiveness, than publish so gross values, that they're of little value to users. 4- place accuracy is seen across the literature. Five doesn't hurt anything. Bankers take it out to 13- decimal places every day.

If you don't see any problem in expanding the number of decimal places from an original measurement, maybe you'd better check some basic engineering textbooks?

[Cd]

Can either of you supply a link to the source of your data ?
- thanks !

I found this article on how the Lucid Aid handles cooling drag, but there are no solid numbers :https://www.wired.com/story/lucid-ai...nt-powertrain/

I'd actually like to ask about how to properly install bellypans and such on EVs with battery cooling in mind.
I assume that having ducting around a battery to cool it would be far more straight through ( literally !) than on an ICE car, with it's many odd shaped parts sticking out.

[JulianEdgar]

Originally Posted by Cd

Can either of you supply a link to the source of your data ?
- thanks !

I did in post 4 in the thread.

[JulianEdgar]

Originally Posted by Cd

Can either of you supply a link to the source of your data ?
- thanks !

I found this article on how the Lucid Aid handles cooling drag, but there are no solid numbers :https://www.wired.com/story/lucid-ai...nt-powertrain/

I'd actually like to ask about how to properly install bellypans and such on EVs with battery cooling in mind.
I assume that having ducting around a battery to cool it would be far more straight through ( literally !) than on an ICE car, with it's many odd shaped parts sticking out.

Not just battery cooling though. Also air conditioning heat exchanger (of whatever type), motor driver controller, motor itself. The Porsche Taycan has radiators much the same size as any other powerful Porsche (going on appearance, anyway).

[freebeard]

I did in post 4 in the thread.

I didn't say that a battery electric vehicle needs to dissipate as much heat as a internal combustion engine car.

I said that the proportional drag of the cooling system appears to be at least as high, if not higher, in battery electric cars as it is with internal combustion engine cars.

Less thermal load, but equal or higher proportion? Given an equal mechanism, perhaps.

Simply put, the amount of drive power available from the HV battery and whether it can be charged quickly depends on the charge level (SoC) and the cell temperature. This results in different temperature targets for the battery, depending on the initial state and the desired final state. The selected driving mode also plays a key role here. In Range mode, the drive, HV battery and minimal on-board power consumption are operated with the best possible efficiency (e.g. the speed of the coolant pumps is reduced). In contrast, in the Sport or Sport Plus modes the corresponding temperature targets for the coolant flow are selected for maximum performance of the electric machines and pulsecontrolled inverters.

The control range is considerably broader than for a conventional combustion engine vehicle, for example. The circuits used in the thermal management of the overall vehicle alone add up to more than 300 states in the Taycan. The optimum energy state at a particular moment is always calculated and adjusted from this. High availability targets, for example for Launch Control, are made possible by a significant and rapid decrease in the coolant temperature. Thermal pre-conditioning for extra quick charging at the calculated place of arrival or pre-calculated arrival time is also possible.

https://e-performance.io/en/article/...mal-management

Without going into the differences between 400V and 800V systems; do the ICE systems control power output based on thermal load?

At least the ICE doesn't require cooling for onboarding fuel.

[JulianEdgar]

Originally Posted by freebeard

I did in post 4 in the thread.


Less thermal load, but equal or higher proportion? Given an equal mechanism, perhaps.


https://e-performance.io/en/article/...mal-management

Without going into the differences between 400V and 800V systems; do the ICE systems control power output based on thermal load?

At least the ICE doesn't require cooling for onboarding fuel.

Interesting stuff from Porsche.

ICE cars can reduce power with excessive thermal load - but nothing like the complexity possible in the Taycan.

[freebeard]

What stood out to me was the cooling during charging. Nothing comparable in the ICE,

[Isaac Zachary]

I think it's going to be hard to quantify the future of BEV cooling when it's still in it's early stages.

• BEV's are more efficient so produce less heat
• But unlike ICEV's they don't have half or more of that heat leaving via the exhaust.
• BEV's also don't have the large temperature differential that ICEV's have, which means that BEV temps necesitate a bigger radiator to remove the same amount of heat.

In most ICEV's you can cool the engine to acceptable temperatures even under full load in 110⁰F/43⁰C dry weather at high altitude with the stock radiator. But put a BEV under the same condition and what kind of cooling system with how much energy loss is going to be needed to keep the battery and inverter at acceptable temperatures?

Just like ICEV's you need a cooling system that can work in pretty much any part of the world. Otherwise you end up with the Nissan Leaf problem. But how small and efficient can that cooling system be made?

You could argue that on most places you don't need a huge radiator to cool a BEV and that the bay could be cooled by a hat pump or flaps that open up more radiator in hot weather. Of course the same technologies could be applied to ICEV's as well.