DanAR
Senior Member
This question is not about a problem but just to satisfy my curiosity about the e-torque system on my 23 Limited. I’ve noticed that sometimes when I come to a stop light and the engine shuts down, the voltage gage continues to show a steady 13.7 to 13.8 volts. Other times when I stop for a light the voltage drops from the 13.8 range to 12.8 volts and then recovers as the engine starts.
Now the 12.8 volt would seem to be correct for a battery at rest or not being charged. As I understand e-torque the generator produces 48+ volts when turning to charge the e-torque 48 volt battery. And the generator (or 48 volt battery) powers an inverter to charge the 12 volt accessory battery with what I assume is 13.8 volts system voltage.
Obviously, the generator, when the engine is stopped, can’t be powering the inverter output of 13.8 volts. So I’m guessing the inverter is powered directly off the 48 volt battery and not directly from the generator output. But that still leaves me a bit mystified why 12.8 volts sometimes with the engine shut down and 13.8 volts other times? I thought it might have something to do with cold engine startup but further observation seemed to dispel that.
We are in the mild season now - maybe something to do with air conditioning & heating fan function? Or maybe it’s just the computer evaluating accessory electrical loads and making a decision to disengage the inverter during engine shutoff or to leave it engaged and charging the 12 V battery from the 48 V battery?
Just curious
Now the 12.8 volt would seem to be correct for a battery at rest or not being charged. As I understand e-torque the generator produces 48+ volts when turning to charge the e-torque 48 volt battery. And the generator (or 48 volt battery) powers an inverter to charge the 12 volt accessory battery with what I assume is 13.8 volts system voltage.
Obviously, the generator, when the engine is stopped, can’t be powering the inverter output of 13.8 volts. So I’m guessing the inverter is powered directly off the 48 volt battery and not directly from the generator output. But that still leaves me a bit mystified why 12.8 volts sometimes with the engine shut down and 13.8 volts other times? I thought it might have something to do with cold engine startup but further observation seemed to dispel that.
We are in the mild season now - maybe something to do with air conditioning & heating fan function? Or maybe it’s just the computer evaluating accessory electrical loads and making a decision to disengage the inverter during engine shutoff or to leave it engaged and charging the 12 V battery from the 48 V battery?
Just curious
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