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Okay, not new to forums, but first time poster. I have something driving me nuts about my new 2013 Dodge Charger RT Plus. I love the car, I love the heated and cooled cupholder feature. But... Where can I find cups or travel mugs that aren't insulated or are only insulated above the cupholder line so I can properly use my heat/cool feature?

I feel like these things could be so much more effective if I could find a properly fitted container to go into them. (preferably dodge emblemed)

If anyone has suggestions please let me know.....
 

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I wonder if a stainless travel mug would work better with the heat/cool feature, compared to a plastic mug? :shrug03:

 

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This one is simple thermodynamics and perhaps I can clear up some misconceptions about heated cup holders.

The simple answer is that an insulated coffee mug works best in a heated cup holder.

I'll explain...

Heat transfer occurs when a hot object loses it's heat to another object. In general, the rate at which it loses the heat is determined by the barrier between the two not the temperature differential. In other words, a mass of coffee doesn't become colder faster on a winter day than on a summer day, it just becomes more cold at the end.

Wait! That doesn't sound right...

It's not...well, not exactly right anyway. I'm ignoring the heat capacity of the barrier for the moment but I'll explain why later.



The barrier properties determine the rate of heat loss. For example...

A paper cup loses about 3*F per minute and an insulated mug loses about 1*F per minute. That means a 130*F cup of coffee cools to 100*F in 10 minutes in a paper cup while it takes 30 minutes to cool to 100*F in an insulated mug.

The heated cup holder in the Charger heats to about 112*F, so why does it keep the coffee hotter longer?

Well it's because of the heat capacity of the barrier has changed (I said I would explain). The heat differenial effectively changes the heat capacity of the barrier (cup). As such, the heat transfer rate decreases as the cup holder temperature increases. The paper cup now has a slower heat transfer rate (maybe 2*F at this temperature).

But this is also true for the insulated mug. It has decreased from 1*F to (maybe) 0.5*F.

At the end of the day, the insulated mug will keep your coffee hotter longer than an uninsulated one no matter if the cup holder is heated or not. The heated cupholder just makes it take longer to cool regardless on the cup type.

The biggest thing to realize is that the heated cup holder is not designed to add heat to a hot beverage, just slow the rate at which it is removed.

The cooling feature works in much the same way but the heat flow is in the opposite direction. :)

Also, the next layer of the calculation of heat transfer is that the heat capacity of the cup holder also changes with temperature (but it doesn't change the conclusion, just the heat transfer rate independent of cup type)
 

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