Normal Voltage for 12V System

[mmarien]

My voltage regulator was set at +/-14.6V at the factory and it reads 14.4V. This is in the yellow range (13V-14.6V) on the Skyview display. I spoke with another homebuilt and his reads in the top 14V range. My old analog gauge green range was 12.5V-14V and it was above 14V when running. The place I bought my battery said 14.6V is too high and the voltage regulator should be set to 13V.

My electrics are a 12V battery, Crysler alternator, Skyview, GTX327 (11V-33V), iCOM A210 (13.8-27.5), PS1200 (13.8-27.5), MTV 12V electric CS prop, Whelen clearance and strobes (12V-15V).

Does anyone have an opinion to what the voltyage should be set at? Is there a reason for the voltage regulator to be set and 14.6V? If I turn the voltage down to 13V as suggested would the PS1200 and iCOM A210 still work? Where did the 12V-13.6V green range on Skyview come from?

 

[meljordan]

13.5 to 14.4 is the normal alternator system voltage to shoot for. 13V is too low to charge the battery in a reasonable time. My plane power alternator normally puts out between 14.2 and 14.4 volts and this has maintained my battery very well. Check the internet and you will see these are normal 12V system voltages.

It is up to you to set the ranges on your SkyView EMS. You can do this in the Sensor Setup menu. I would suggest a green range of 13.5 to 14.4 with yellow ranges of 13.0 to 13.5 and 14.4 to 14.6. Beyond those ranges you need red to set off alarms as you have a problem.

If you have an adjustable regulator, I would suggest setting it in the 13.8 to 14.2 range.

Most modern aircraft devices can handle voltages down to 10VDC and still function.

Regards,
Mel Jordan

 

[pbennett]

Typical sealed lead acid batteries have a recommended float charge voltage of 13.8V. This is where, like in a security system, you want to hold the battery fully charged but not drawing significant charging current for those long periods when it is not being called on to power the system. For automotive and aircraft use, the battery provides a huge current to the starter, then has to recharge in a relatively short time, like a one hour flight. Most sealed lead acid batteries specify about 14.2V for this application, limited by the temperature rise caused by the charging current still flowing when the battery is fully charged.
Bear in mind that the Skyview measures voltage at its input, not at the battery terminals. These can vary by fractions of a volt depending on current flowing, number of connections and length of wiring run.

Peter

 

[mmarien]

Thanks guys

I think I will turn down the regulator to 14V and adjust the Skyview ranges as suggested. I thought that maybe the Skyview ranges were standard.