[Ovmsdev] Nissan Leaf Updates

[Tom Parker]

Hi,

I've made a few changes to the Nissan Leaf support.

Configurable battery sizes to support 30kWh batteries. Parameter 21 is 
now initialized to 281 gids if it doesn't contain a string that parses 
to an integer. Change this parameter to change how many gids represents 
100%. If you have a 30kWh battery you probably want to set it to 363. I 
discussed options to change the SOC calculation when I first started 
working on OVMS and Tom Saxton made a convincing argument that OVMS 
should display the amount of energy remaining in the battery, not how 
full it is. I'm not planning to push the other options I discussed back 
then as it turns out he's right, you want to know that when it tells you 
60% you have 60% of some fixed amount of energy, not 60% of whatever the 
car thinks it can do today.

You'll have to restart the OVMS after changing this parameter for it to 
take effect.

Ambient temperature. The value I'm getting isn't quite right, but it's 
close to the eyebrow dashboard display. Leaf Spy mentions something 
about a correction in it's change log but I haven't tried to track it down.

Battery temperature. The BMS sends the battery temperature in a 
multiplexed field on a regular basis, so no polling is required. I've 
had battery temperature via polling in my development branch for a while 
but, on my car at least, this causes a relay to click during charging so 
I didn't merged it upstream. I did some reverse engineering with a CAN 
bus man in the middle and discovered how the battery temperature on the 
dashboard works.

Remote Climate Control switch off. It turns out at least some Gen 2 cars 
don't turn off their climate control after you remote start it. They 
even continue remote climate control after driving the car and then 
turning it off. Now I send the off command after 15 minutes on battery 
power and 30 minutes on grid power, or if the car turns on. I've 
discovered that on Gen 2 and later cars the plugged in detection doesn't 
work. This isn't hugely surprising because they changed the battery 
charger between Gen 1 and 2.

This last change hasn't been merged yet because I only just now sent the 
pull request.

I've also found that remote climate control doesn't work at all on 2016 
models -- Nissan moved the TCU to the Car CAN bus (it was on the EV CAN 
bus) and changed the messages.

Expect an update for 2016 remote climate control and Gen 2 plugged in 
detection soonish.