Battery cooling while charging

I don't think you can default it to yes. I never turn it on, I simply lower the windows while charging.

 

The first time I got that message and I had DrPrius running the traction battery temps were reading 100 F
The second time I got the message and could also see the DrPrius temp reading they were 95 F.
Just to help you get a handle on when and why you'll see that message and be able to answer Yes before the message disappears. I've also missed answering the message at least a few times.
I agree it's not ideal to have that message and only give 5 seconds to find the steering wheel button(s) to make the selection.

 

I'm sure the battery charging ecu monitors the battery temperature while charging and can slow down/cut back the amperage applied; if the battery gets too hot.

 

which might be why the cooling feature is available to help slow the charge into the battery when the ECU's decide to switch on the battery cooling / pre-conditioning feature. It's not always switched on at the same time charging starts. Battery cooling may not be exactly the same as pre-conditioning when ambient temps are in the 90 F or above range, but they look identical to me from what is shown by the 3 LED's on the Gen 4 dash, the amount of time the cooling runs and the heat pump / ac unit as it spins up.

I've also been able to run pre-conditioning several times during one charging session when ambient temps are really high and I'd like to use cooling for more than the default 10 minutes per charge session.
Also, pre-conditioning is controlled the the ECU's and can only be used when the ECU's permit. So it's not always accessible when pushing the button on the fob.
Also pre-conditioning will run without the Prime being plugged in, if the ECU's determine the conditions for running it are met.