I did a search and it actually raised more questions in my mind. Here they are. 1. Is it a good idea to trickle charge the 12v starting battery every so often to ensure it is staying fully charged? One thread led me to believe it might not be necessary since the Prius battery gets charged so much by running the motor. 2. If yes, is the best way to do this via the electrical box in the engine compartment? I have a conventional charger, I assume I hook the negative to the frame? 3. One post I read said to limit the trickle charge to 4amps or less, is that true? 4. Anything else I am not asking about this? Thanks in advance for any help. Kirk
The 12 volt battery does not start the engine, Motor Generator 1 draws from the high voltage battery to start the engine. The 12 volt battery powers the accessories, including the computers. As such, it is smaller (both physically and electrically) than a normal car battery. If you were not running the Prius for over 2 weeks, trickle charge it.
The 12V battery is not charged by running the motor. The 12V battery is charged by a DC to DC converter from the HV battery. Trickle charging the 12V battery with a conventional dumb charger will lead to an early death. If you park your Prius for extended periods you may want to use a smart battery charger to maintain the 12V battery. The jump point under the hood is the most convenient spot. Attach the negative to a grounding stud. Some PC members have installed a connector for a battery minder. This is a very small battery. Use a smart charger and you won't have to worry about amperage. No. Tom
