I cannot comment on Mitsubishi Corporation responding to emails Phone calls or letter but can comment on the Battery Temperature increasing whole trickle charging.I am curious how you got a response from Mitsubishi. I have been trying and can't get anyone in USA to respond, I left email requests on their web site and tried calling their main line. This has been discouraging as I have had Mitsubishi products for over 20 years and they were all fantastic vehicles, all reliable and some living long ( more than 240K miles) lives.
I wonder what happens when the PHEV is plugged in outside in -30C ( -22F) temps? Could the trickle charge, assuming it is fully charged, be enough to raise the battery temperature?
Simple answer is NO.
We are presently getting temperatures of between -5 to -9'C and I have been checking the Battery Terature on the car Screen and when I compare tge Battery Terature prior to charging and 3/4 of full charge on Level 2, the Battery Temperature gauge only increase a small amount.
When driving and Heat Pump on, tgs Vattery Temperature does not increase at all.
I will try to post some photos tge next time I place car on charge.
Tge software upgrade will do nothing to allow warm up thd Battery.
The 2023 to 2025 PHEV may fail to start when Temperatures reach -30'C and lower because they do not have an Interior Main Battery Resistive Heater.