Everything dead after “stop vehicle check brakes” warning

[Quasar]

I have a 2017 Soul EV I’ve had for one year. Not a single problem until today. I drove somewhere to pick some thing up and when I got there, I turned the car off and then pushed the start button again so that I could have some air running for my teenager in the car while I was out of the car. I expected to be only out of the car for two minutes, but ran into someone and was probably about 10 minutes instead. When I went to start the car when I got in, it put up a warning that said “stop vehicle check brakes”
and I couldn’t shift into reverse. I tried cycling through, and then I got a new warning that I needed to push the start button with my key fob, which I guess is what happens when a key fob battery dies. Started again when I did that, but still the check brake warning. I went through a few iterations of trying to make things work before turning it off and starting to look up the warnings I was getting online. When I went back to try one more time, I got nothing at all, as if the entire vehicle is dead.

I think it seems likely that I accidentally discharged my 12 V battery by leaving the air running when the vehicle was not fully on. (I still have trouble knowing when the car is in which mode.) but would that explain the check brake warning? I had to get a ride home and leave my car behind and I’m trying to decide if I need to have roadside assistance tow it to the nearest dealership, which is 20 miles away, or if I should start by jumping the 12 V battery. I certainly don’t want to drive it if there’s something actually wrong with the brakes, though.

 

[Quasar]

Jumped the battery and all is well. Now I know I need to have the green car light with the arrows underneath in order to run ac and such off the main battery. Should the 12v battery be fine with me just hooking up to our home charging station? Will that charge the 12v as well?

 

[IanL]

Yes, the auxiliary battery will be charged during the charging of the propulsion battery, but it sounds like the aux is on it's last legs if it died after only 10 minutes of running the aircon. I would have it tested with a view to replacement if necessary.

As you have to leave the vehicle with the "ignition on" to run the aircon, do brief your teenager not to touch the shifter.

 

[notfred]

I agree that the 12V needs testing to die so quickly.

Also note that while it is charged from the main battery, it's only the equivalent of driving around in an ICE car. So if the 12V is fully discharged it's better to initially charge it while disconnected from the car with a separate battery charger.

I should also add that you get no warning if the 12V is almost dead. In an ICE car you would hear the engine cranking slower when you start it, realise that the 12V is getting weak and replace it before it leaves you stranded somewhere. In the Soul EV there is no engine to crank, so the 12V tends to die without warning.

 

[invader166]

Just a quick fyi in case noone stopped to explain this.
The reason why you got a “stop vehicle check brakes” notification, is because the power brakes motor used to create the vacuum is powered by your 12 volt battery.
Basicly the car is warning you that you don't have power brakes anymore.