More discussion on this here:
https://github.com/openvehicles/Open-Ve ... issues/311
"Now when we are approaching the really cold months, it would be extremely beneficial for a Nissan Leaf to have more control for the battery heating. As you northern Leaf drivers might know, if the temperature of the battery drops below freezing, the Leaf will not fast-charge. What if we could control the heating of the battery like on a Tesla? This would be a game changer!
First of all, to see if your Leaf is equipped with DC heating elements inside the battery, there is a signal in the 0x5C0 frame that has 0/1 if pads are present or not. Frame4 bit0
In 0x5C0 frame 0 bit 5, there is a heating start send request and in bit4 there is a stop heating request.
The theory is that to start heating, you write bit5 to 1. BUT there is also a send request bit that might be necessary to write also. It's in frame 1 bit 0 (Batt_Heater_Mail_Send_Request)
Anyone got a Leaf equipped with heater pads?
This message does not appear to have CRC or PRUN protection. Also this should only be possible on AZE0 Leaf!"