Saw this over CleanMPG Freescale Introduces Intelligent Sensor for Car Battery Monitoring - CleanMPG Forums Anyone interested in making a few using this chip? Winston
For gen2 Prius from the OBD port we can get the 12V battery voltage, the HV battery temperature and outside air temperature. The latter two give a rough estimate of the 12V battery temperature. The chip above adds the capability to measure 12V battery current which I don't know whether we can get from the OBD port or not. What I do is periodically, maybe twice a month, put the battery under some load by turning on headlights and rear defogger and look at the battery voltage. This establishes a baseline. I posted some data here: http://priuschat.com/forums/gen-ii-...-trip-record-fun-early-problem-detection.html If I start to see the voltage under load to drop significantly then I know the battery may be sick.
What I was hoping for was a package that I would install and forget ...until it sounds a Klaxon warning of impending death of the 12V battery a couple of weeks before the actual event. A day downcount on a LCD counting down the days to battery failure is good.
