[[email protected]]

We are getting what was an intermittent message that our 12V battery is low, and the car will not switch out of PARK. Now it is permanent. Car was towed to the dealership today. Anyone else seeing this?

In the not so distant past we have had issues with the radio not working. The radio arbitrarily switching to the phone instead of Sirius. The Infotainment system locking up and not having any display. The GPS display being lost when Android Auto decides not to stay sync'ed with the phone. Blind spot indicators light when nobody is there and will not go off. The Fan going full blast with no control (often). The heater would not turn off, it would turn itself back on. You have to expect some bugs with a very 1st edition, but this software has stayed glitchy.

We like our Bolt even though it does not have a pocket for my sunglasses, it does not have the built in 3 garage door openers (other car is a Camry Hybrid, not a high end luxury car and it has both of those). No power seats? Just GM being ridiculously cheap. But I do like the rear-view camera.

 

[TFPDrive]

Your car told you exactly what was wrong. Things on your 12v system were acting weird and then you got a warning that your 12v battery was low. Your battery died.

Not sure what the last paragraph has to do with it. I don't think the lack of power seats caused your battery to die. A 12v battery swap will likely solve all of the issues in your second paragraph.

 

[MichBolt]

Electric vehicles like the Bolt actually have 2 battery systems - a "traction battery" that moves the vehicle (~400V nominal), and a regular 12V battery that operates "typical" car electrical systems like your radio, headlights, windshield wipers, etc. Furthermore, the 12V battery is used to start the vehicle's computers (for safety reasons). Therefore, a dead 12V battery will result in the car not being able to start.

12v Battery Charging

How is the 12v battery maintained under normal operating conditions ? Is the main battery always connected or only when the car is 'ON' ?

www.chevybolt.org

 

[[email protected]]

Electric vehicles like the Bolt actually have 2 battery systems - a "traction battery" that moves the vehicle (~400V nominal), and a regular 12V battery that operates "typical" car electrical systems like your radio, headlights, windshield wipers, etc. Furthermore, the 12V battery is used to start the vehicle's computers (for safety reasons). Therefore, a dead 12V battery will result in the car not being able to start.

12v Battery Charging

How is the 12v battery maintained under normal operating conditions ? Is the main battery always connected or only when the car is 'ON' ?

www.chevybolt.org

I am an Electrical Engineer. I clearly understand the 2 different battery systems and what they do, just like the car has multiple cooling systems. The 12V was not dead, or the problem would not have gone away so quickly before. It might be now, but I do not live in a zone that changes temps much during the year. This car has never seen freezing weather and nothing over the upper 90's and it is used at least 6 days a week. Strange that the battery would die so soon. All of the issues we have seen with this car so far are software related. Sad.

 

[GregBrew]

In my 20+ years of experience with EVs, the vast majority of times that they have had any "weird" behaviors was because of a weak 12V aux battery. I have a "smart" multi-stage charger/maintainer for AGMs that I regularly (every 60 days, or so) put on their 12V aux batteries. I haven't had any "weird" behavior since I started doing this. The charger/maintainer also indicates when the battery has reached its end-of-life.

 

[Dark-Fx]

Keypass with approach detection turned on ran my 12V battery down to about 7V when I had parked in my attached garage. I had just finally enabled it the day prior. Apparently the keys were close enough in the house that it was constantly cycling it. That was like a year and a half ago, have never changed the battery out since then and turned that **** off once I had the battery recharged.

 

[MichBolt]

I am an Electrical Engineer. I clearly understand the 2 different battery systems and what they do, just like the car has multiple cooling systems. The 12V was not dead, or the problem would not have gone away so quickly before. It might be now, but I do not live in a zone that changes temps much during the year. This car has never seen freezing weather and nothing over the upper 90's and it is used at least 6 days a week. Strange that the battery would die so soon. All of the issues we have seen with this car so far are software related. Sad.

Apologies - one never knows the background of Internet posters, so we can't assume any background knowledge.

Having said that, as an electrical engineer, I'm sure you understand that you cannot say for certain if the 12V battery was or was not dying unless you had actually tested it. As for "the problem would not have gone away so quickly before" - can you be more descriptive? Do you mean you received the error upon startup, then the error message disappeared quickly after startup? That could be explained by the fact that after startup, the 12V system draws power from the traction battery via voltage inverter / 12V bus rather than drawing down the 12V battery itself.

The Bolt will also check and charge the 12V battery with some frequency, at different intervals depending on whether the Bolt is plugged in. If you happened to start the car shortly after such a charging session, you may not see the problem.

You posted a concern on a forum, and we're just trying to help you diagnose possible causes. Based on the information you have provided thus far, it remains possible that the behavior you see is consistent with the 12V battery "dying."

 

[BillG49]

Did you tell us the model year of your Bolt, or how long you've had it?

 

[Sean Nelson]

The 12V was not dead, or the problem would not have gone away so quickly before.

Every time you turn the car on the Accessory Power Module fires up and supplies 14V power to all of the low voltage systems in the car. This also charges the 12V battery. If the 12V battery is weak, it may well cause weird behaviour that goes away temporarily after it's been charged - but then returns if the car has been left turned off for a while.

There is a rich history of weak 12V batteries causing one or more of the car's myriad sensors to spew garbage as input to the control computers and resulting strange and inexplicable behaviour. Thus, when weird things happen the advice is always to do a load test of the 12V battery (merely measuring the no-load voltage isn't a very good test).

So when we hear that the car actually told you that it had a 12V battery problem the natural reaction is to believe it.

12V batteries can have a history of abuse if the car sat around on the dealers lot for an extended period of time. Some of the car's systems are always "on" and they will drain the 12V battery if it's left off long enough (i.e., a few to several months). If the abuse is severe it will show up right away, but it could also take a year or two to make itself known.

The problems you were experiencing with the radio may or may not be related to this. The infotainment system is known to have its share of glitches even at the best of times. A quick way to reset it is to hold the "Home" and "Next" keys (beside the volume knob) down for 10 seconds, which causes it to reboot. If that solves the problem then it's likely just a software hiccup.

 

[WJRegen]

12v battery died on our 2019 Premier within two weeks of driving it off the dealer lot. I was traveling for work and my wife called me in a panic.She was running errands. I had to resolve all that by phone. Not a good intro to the EV life for her, but now she's a bigger fan of the Bolt than even I am.