On 2/15/2010 3:28 PM, [email protected] wrote: > Thanks, it works on my 396 shows 7.4 volts on the internal battery. I > will se what it shows when hooked to the airplane cig lighter. (when I > get it back form my annual in March). You say it should be in excess > of 12 volts? > > A fully charged battery should read about 13 volts ( A lead acid cell is good for about 2.2 volts and there are 6 of them.) If the battery is under a load, it will read a little less. If the charging system is putting out more than the electrical system is drawing you will see a voltage higher than the battery voltage. 13.8 - 14.2 volts is typical.
Most mechanical regulators used in aircraft are not temperature compensated,so the output is somewhat of a compromise. Don't know about the solid state ones. The battery can take a higher charging voltage at lower temperatures without damage and will charge at a slower rate for a given voltage. When I was a kid we used to adjust the voltage regulators on our cars every spring and fall... John
