Alternator/Battery ???

July 23, 2012, 11:28:36 am

Not sure where my problems is.........or if I even have a serious problem just about to happen. So I need a little advice please.
While driving, at the beginning of the drive, my analog battery gauge reads about 12.5-12.75V then a couple hours later it reads just under 12 to 12.25V while my digital readout registers from 12.6V up to 12.8V. At the end of the trip when I shut down, the inverter/charger gauge reads about 12.4V on the engine batteries before plugging into shore power.
While parked and not connected to shore power, I set the engine to run at high idle --- 900-1000 rpm and put my volt meter on the engine battery terminals and they registered 13.27V. So I believe that the alternator has not died. I thought that the alternator should be putting out a slightly higher voltage, but I'm not sure.
The batteries are just under 5 years old, so that may the problem. I've checked the water lever and it is just fine.

Any recommendations would be appreciated.
Thanks

Denny Zarnt CC -- 2001 42' Affinity, Bed and Breakfast # 5972

Re: Alternator/Battery ???

Reply #1 – July 24, 2012, 12:37:31 am

Yahoo Message Number: 81098

I wouldn't rule out a bad alternator - with the voltage only reading 13.2 volts, I would suspect that one part of the diode stack has failed - you should be getting closer to 14.5 volts out of the alternator (at least immediately after starting the engine when the alternator is trying to replace the heavy starting discharge of the batttery).

John

'06 Inspire DaVinci #51905

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