I want to spend 15 or 20 minutes learning the various screens on the 7inch display. While doing that I would like to use as little energy from the battery as possible. Should I pull into a parking spot set to P and put on the foot parking brake and leaving the car on go about going through the various options on the screen? Or, should I turn the car completely off then use the accessory mod by just pushing the start button without depressing the brake peddle? Or does it make any difference with either way being about the same drain on the bettery?
i think acc mode will use less juice. and now having a bigger battery, you probably don't have to worry about the 12v as in the past.
I drained the 12 volt battery on my Gen 2 listening to the radio while waiting for my wife. I have been wary ever since, but this larger battery does seem to have more life to it - especially because it is new. I hate it when I park in "ready" mode and the engine cycles on to charge the traction battery - so I continue to be an "ACC" user and so far, no problem.
The first option you described , with the car in "READY" mode, takes power from the large traction battery. If that battery starts reasonably well charged and the engine is still warm, you have a reasonably long time to study the various screens before the engine comes on to restore charge. Your other option takes energy from the much less powerful 12-volt battery. If it's like the 3rd-generation, you'll have to use the "ON" mode (two presses of POWER button with brake not depressed), which sucks charge out of the 12-volt even faster than "ACC" mode does.
