This question really goes beyond RX but since this is the forum I frequent, I hope a knowledgable person would reply.

For non-hybrids, the battery is charged by an alternator. Since alternators produce electricity by spinning conductors in changing magnetic field, during start --- the change in magnetic field spikes [from 0% to 100+%] and produces a sharp spike in generated voltage. Although the battery +12v acts as clamp but never the less the voltage spike is enough to fry any accessory connected to +12v wire. In order to prevent this, the ACC [accessories circuit] line is disconnected when the key is moved to 'start'.

With hybrid, how is the generator spike controlled? Is there an electronic isolator? How are accessories safely connected to the 12v?

Salim

 

There is no generator and starter connected to the 12V system so is not subject to anywhere near the same variability that results from starting a car or the greatly changing rpm of an alternator. When the hybrid system is on, the 12V system is supplied with a steady ~14.4V from the hybrid battery. I believe a transformer is built into the battery pack itself.

 

From what I understand there's a component sitting on top of the ecvt called a dc to dc converter which transforms the hybrid voltage to a much lower one to start the car. I suspect any "isolater" if any be contained within this unit. Good Question.