[boba]

Got into my Bolt this morning and the screen behind the wheel in big red letters said that charging
was not possible (can't remember the exact words). Pressing the on button resulted in a normal startup and
trip. At home I plugged in power and the car is now charging normally. Anyone know what happened and if there is
anything to worry about?

 

[GJETSON]

Since the message cleared itself, I would not be worried. If it comes back, especially if it doesn't clear after restarting, I would see the dealer. Lots and lots of little computer modules in these cars. Even if something is a millisecond slow responding, it will show a fault.

Many fault messages end up being caused by a low 12 volt accessory battery.

 

[GregBrew]

What he said ^^^^.

A weak and/or failing 12V Auxiliary Battery is the bane of EVs. It's been the cause of the vast majority (90%+?) of odd behaviors in the more than half-dozen EVs I've driven since 1997. Hooking up a high-quality, multi-stage battery tender/charger (that's AGM compatible) periodically, greatly reduces said behavior.

 

[p7wang]

The Bolt 12v battery is AGM?

 

[wesley]

The Bolt 12v battery is AGM?

Yes.

 

[boba]

So far the can't charge message has not come back after 250 miles of travel.
Just got around to measuring the voltage of the 12 volt battery:
Motor off = 12.8. Motor on = 14.5. I assume that is normal.

 

[GJETSON]

So far the can't charge message has not come back after 250 miles of travel.
Just got around to measuring the voltage of the 12 volt battery:
Motor off = 12.8. Motor on = 14.5. I assume that is normal.

Yes. That is in the range I normally see on Torque Pro. But rarely (hardware or software glick?) will see it below 12.5 volts.

 

[brulaz]

What he said ^^^^.

A weak and/or failing 12V Auxiliary Battery is the bane of EVs. It's been the cause of the vast majority (90%+?) of odd behaviors in the more than half-dozen EVs I've driven since 1997. Hooking up a high-quality, multi-stage battery tender/charger (that's AGM compatible) periodically, greatly reduces said behavior.

Not just EVs I think. All modern vehicles with extensive computer and electronic systems. They run down the battery fast when stored, and give a raft of errors when the battery is low. I have to keep a charger on my truck's batteries when stored for the same reason.

Have wondered before why EVs have a separate 12V lead acid battery. Would have thought a DC-DC converter would be fine to provide 12V for accessories. But have been told that it's not simply a second accessory battery, but a separate (fail-safe?) electrical system that runs most electronics/computers and tests the main drive battery before and during operation.