Plug-in Charging System Malfunction message

The battery is air cooled and with a 200W heater element to warm it up. Why does running the ICE help warm it up?

 

Ok, in very cold conditions heatpump struggles heating the cabin.....where the ICE comes to play...heating the cabin thus the traction battery.

 

Oh true, the battery vents are in the cabin so heating up the cabin helps heating up the battery.

 

Update on the MIL.
Toyota replaced the charger assembly and it has worked as it should for a month now. It has been cooler out so next summer should be the real test, when charging in the summer sunshine.

 

Whenever it was a sunny day and needed to charge, I opened the windows so the interior would not get too hot. Sending 50C air to the battery instead of cooling it down is not a good idea.