Got the following voltage data. The car has been sitting for approx 18 hours: 12.3 - accessory mode (nothing on) 11.7- lights on 11.4- rear window heater on 11.1- lights & rear window heater on together Was reading the voltage should be between 12.6 and 11.9, so at 12.3 I guess I'm doing OK. Right?
It's not in terrible shape. Did you drive short trips or long ones before your Prius sat idle? If short trips, then your 12v just is not fully charged. If long trips, keep an eye on the battery as it is showing some weakness. JeffD
I just got back from a 330 mile trip without stopping. Will charging my cellphone while driving shorten the life of the 12V?
So just keep an eye on the battery. No, the charging system can supply up to about 100 amps for accessories without problems (except for a drop in MPG to supply the energy, about 1 MPG lost for each 10 amp of current load). JeffD
Quick question, where did you measure the voltage? If by chance you read this on the screen in Service Mode, I would recommend reading it with a DVM right at the battery terminals or at least on the jump terminals in the engine fuse box. I read a difference of -0.7V on the Service Screen versus with a DVM right at the battery terminals.
The best way is to have the vehicle shut down for 6+hours then use a digital volt meter to measure voltage at the battery terminals.
