Lots of speculation here, so some clarity.
The Lighting is not a "bleeding edge tech" vehicle, in fact it is pretty dated tech (I, for one, like this about the vehicle... tried & true stuff). Most, if not all of the following will apply to the Lightning.
The 12v battery is responsible for most of the standard vehicle electrical operations we are used to in vehicles. Lights, gages, climate control, stereo etc. Unlike an ICE, an EV has no alternator to maintain the 12v system. A simple DC to DC converter is used in its place taking 400v (nom) from the traction pack and stepping it down to 14.4v (ish) to run the 12v systems and charge the 12v battery.
An EV will not "start" if the 12v battery is dead. Even if your traction pack is charged.
Because the DC to DC converter is a very robust and efficient way to get a lot of 12v power, the 12v "accessory" battery in EVs is often smaller than what you would find in an ICE (plus, it does not have to start an engine). This battery is smaller and less expensive, but unfortunately more prone to failure; much like a motorcycle battery.
The DC/DC converter is always on when the vehicle is on. Otherwise, the vehicles lights and systems would quickly drain the small 12v battery. Want to charge your 12v battery? Turn your vehicle on. NOTE: Tesla drivers who travel know that they should turn on the climate control via the phone app once a month to "wake the car up" while it is stored so the 12v battery does not die. This does not work with all EVs, but hopefully it does with the Lighting.
Most EVs do not run the DC/DC converter with the vehicle off. It would cause too high of a parasitic draw (there are losses involved) on the traction pack.
It is my opinion that EVs should trigger the DC/DC converter when plugged in, to also keep the 12v battery topped off. MOST DO NOT. I travel, and both the GM EV and my Teslas will suffer 12v death if left long enough without being "awakened" as per above.
"12v death" in an EV is much more common than it should be. Fortunately, it is very easy to fix.
A final note for those wanting to do testing on your own DC/DC converters. The big wires are the low voltage side. Seems counter-intuitive, but lower volts = higher amps.
The Lighting is not a "bleeding edge tech" vehicle, in fact it is pretty dated tech (I, for one, like this about the vehicle... tried & true stuff). Most, if not all of the following will apply to the Lightning.
The 12v battery is responsible for most of the standard vehicle electrical operations we are used to in vehicles. Lights, gages, climate control, stereo etc. Unlike an ICE, an EV has no alternator to maintain the 12v system. A simple DC to DC converter is used in its place taking 400v (nom) from the traction pack and stepping it down to 14.4v (ish) to run the 12v systems and charge the 12v battery.
An EV will not "start" if the 12v battery is dead. Even if your traction pack is charged.
Because the DC to DC converter is a very robust and efficient way to get a lot of 12v power, the 12v "accessory" battery in EVs is often smaller than what you would find in an ICE (plus, it does not have to start an engine). This battery is smaller and less expensive, but unfortunately more prone to failure; much like a motorcycle battery.
The DC/DC converter is always on when the vehicle is on. Otherwise, the vehicles lights and systems would quickly drain the small 12v battery. Want to charge your 12v battery? Turn your vehicle on. NOTE: Tesla drivers who travel know that they should turn on the climate control via the phone app once a month to "wake the car up" while it is stored so the 12v battery does not die. This does not work with all EVs, but hopefully it does with the Lighting.
Most EVs do not run the DC/DC converter with the vehicle off. It would cause too high of a parasitic draw (there are losses involved) on the traction pack.
It is my opinion that EVs should trigger the DC/DC converter when plugged in, to also keep the 12v battery topped off. MOST DO NOT. I travel, and both the GM EV and my Teslas will suffer 12v death if left long enough without being "awakened" as per above.
"12v death" in an EV is much more common than it should be. Fortunately, it is very easy to fix.
A final note for those wanting to do testing on your own DC/DC converters. The big wires are the low voltage side. Seems counter-intuitive, but lower volts = higher amps.
