DakotaHawk
Well Known Member
The no-load voltage on my PC680 has been trending down over the past year, and it's becoming noticeable when I attempt to start my engine on a cold day. The cold cranking amps just aren't what they used to be.
Another thread about voltage drop across diodes got me thinking about how my system is set up.
My electrical system is based on Nuckoll's electrical schematic for a single engine/single alternator/single battery system. In a nutshell, during normal ops, power goes from
the Battery
to the Battery Contactor
to the Main Bus
to a Diode
to the Essential Bus
During abnormal ops, power goes from
the Battery
through a "Essential Bus" Switch
to the Essential Bus
So here's the problem... Currently, I have my Alt Field Ckt Bkr and my Alternator Voltage Sense both come from my Essential Bus. But my Essential Bus voltage runs about 1.4volts lower than my Main Bus and my Battery voltage (due to the diode). So when the voltage regulator senses voltage, it's seeing a voltage that is 1.4 volts too low, and begins overcharging my battery in an attempt to get my Essential Bus up to 14.4 volts.
So now I'm wondering. Am I frying my battery? Should I swap the Alt Field and the Alternator Voltage Sense over to the Main Bus?
My electrical system is based on Nuckoll's electrical schematic for a single engine/single alternator/single battery system. In a nutshell, during normal ops, power goes from
the Battery
to the Battery Contactor
to the Main Bus
to a Diode
to the Essential Bus
During abnormal ops, power goes from
the Battery
through a "Essential Bus" Switch
to the Essential Bus
So here's the problem... Currently, I have my Alt Field Ckt Bkr and my Alternator Voltage Sense both come from my Essential Bus. But my Essential Bus voltage runs about 1.4volts lower than my Main Bus and my Battery voltage (due to the diode). So when the voltage regulator senses voltage, it's seeing a voltage that is 1.4 volts too low, and begins overcharging my battery in an attempt to get my Essential Bus up to 14.4 volts.
So now I'm wondering. Am I frying my battery? Should I swap the Alt Field and the Alternator Voltage Sense over to the Main Bus?