Car modes and batteries - when are the batteries charging and draining

[kishdude]

I wanted to create a thread to discuss the various modes the car may be in and what the batteries are doing during these modes. There are 2 batteries - the traction battery and the 12v battery and it is somewhat of a mystery what is happening to them in the various modes the car can be in so I'm starting this thread to try to nail this down. Here are the mode I can identify and what I think is happening to the batteries:

1) Car off - The mode when the car is off and locked and not plugged in. Traction battery - slowly discharging (I've seen reports of about 1% per day). 12v battery - ? slowly discharging - I know that the 12v is required to turn the car on so I'm guessing that it is slowly discharging during this mode.

2) Acc Mode - There are two ways I've seen that the car can get into this mode - 1) unlock the car and sit in the driver's seat with the key fob but don't press the brake pedal. 2) Park the car and remain in the car in the driver's seat and after a while the car will turn "off" but still be in acc mode. In this mode the radio, HVAC, screen, and seat heater still work. One question is how long the car will stay in this mode as long as you are still in the car - my guess is indefinitely. Traction battery - discharging (this is needed to run the HVAC and other functions), 12v battery - ? I don't really know what is happening to the 12v battery here. I'm hoping that it is not discharging, but I'm not sure.

3) Drive Mode - The car is on and you are able to drive. Traction battery discharging. 12v battery charging? I'm assuming that this is one of the mode when the 12v battery charges, but I'm not sure.

4) Car charging - The car is plugged in and is charging. Traction battery charging. 12v battery charging? Don't know for sure what the 12v is doing here as well but I'm guessing that it is charging.

5) Charging finished - The car is plugged in and has finished its charge. After the car has finished a charge, it seems to go into car off mode and never goes back to charging mode but I'm not sure. I'm guessing here that the batteries are doing the same as car off where both batteries are slowly discharging, but I'm not sure.

Again, these are my guesses as to what is happening and I'd love some input from others who have more definitive answers. As we have seen from other threads, the 12v battery is critical to get the car to unlock and turn on. I really want to get a good handle as to what causes the 12v to discharge and charge.

 

[mnx]

Did you read this thread already? Traction Battery, 12 volt battery and Vampire Load... How does this work??

I would think that whenever the car is "on" modes 2-5 (ie. main contractor closed). The car is monitoring the 12V battery and charging it accordingly.

 

[FlasherZ]

This probably should be combined in some sort of a thread that includes the information from the two threads.

There are likely 2 submodes of #1 - there's "deep sleep", which powers off the two display/management systems, and "standby", where those systems are running (but remain dark). I wouldn't call it "car off" because it can be confused with the "Car Off" message on the dash which is your "acc mode" above.

 

[widodh]

Did you read this thread already? Traction Battery, 12 volt battery and Vampire Load... How does this work??

I would think that whenever the car is "on" modes 2-5 (ie. main contractor closed). The car is monitoring the 12V battery and charging it accordingly.

I agree, that topic seems to be the right location for this discussion.

We are really seeing a huge growth in new topics every day.

Please keep the discussion to existing topics

 

[kishdude]

Did you read this thread already? Traction Battery, 12 volt battery and Vampire Load... How does this work??

I would think that whenever the car is "on" modes 2-5 (ie. main contractor closed). The car is monitoring the 12V battery and charging it accordingly.

I did read the other thread, but I'm not entirely convinced that in mode 5 - the car is plugged in and finished charging, that the main contractor is closed. There have been many reports of dead 12v batteries in this situation that renders the car inoperable since the 12v battery is needed to close the main contractor.