I don't know what the trip voltage is, but the under voltage light on
the panel of the C182 I fly comes on below 800 RPM with only the
avionics and rotating beacon.

Nathan Young wrote:
: I would be very surprised if that is normal behavior. What kind of
: loads does the ammeter indicate? (With the landing light on/off).

wrote:
If there's a voltmeter (built-in), chances are there *isn't* an ammeter.
Also, alternators do not put out their full rated current capacity until somewhere
above idle. The will put out *something*, but won't be able to regulate beyond full
field current. Also, the regulators in alternators are typically proportional
control, so by definition they have a steady-state error that's proportional to the
load being drawn.