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An EV has two power systems, 12V (typically) for the car accessories, and 120V for the drive motors. And if the 12V system is down, you can’t drive the car (ca
by falcolas 3y ago
An EV has two power systems, 12V (typically) for the car accessories, and 120V for the drive motors.
And if the 12V system is down, you can’t drive the car (can’t close the contactor that connects the 120V batteries to the system).
So, in theory, you could jump the 12V system so you can engage the 120V system.
- scotty79 3y agoThe design that allows 12V to completely discharge while there's charge in high voltage batteries is idiotic. I ran into that in Toyota hybrid. Why there's no manual override that enables charging of 12V battery? It could be under the hood and turn off automatically when the voltage in 12V battery is high enough.
- rnk 3y agoThis same problem happens in evs where due to some problem the 12v discharges. When everything is working the 12v is charged up from the main battery bank. Tesla in the early days sometimes ran down the 12v and it wasn't that uncommon, there were problems with runs of batteries yielding poor ones; I think they had messed up software that wasn't charging the 12v enough, but they made changes to address that long ago. On my second ev, a rivian, I just had to have my 12 battery replaced. They said sometimes the 12v batteries just die on them.
- sgerenser 3y agoSome Hyundai hybrids and PHEVs have this (I saw it in the original Ioniq). It's a button you press that temporarily charges the 12V battery through the high-voltage system rather than being always enabled, but it seems like a great idea.