[Elecraft] KX3 Power Sense

[N4CW at aol.com]

It's my understanding that the KX3 will "sense" the input voltage and  
adjust power output correspondingly.
That is, if I'm using internal NiMH batteries, power output will be limited 
 to 5 Watts, and if I'm powering the
KX3 from a 13.8 Volt source, power output will be allowed to go all the way 
 to 12 Watts. Right?
 
Well, here's what I'm experiencing: Let's say I've got my power set to 10  
Watts using a 13.8 Volt source and my KX3 display indicates 10W output. If I 
 turn off the KX3, unplug the 13.8 Volt source and run off batteries, my  
power out (as indicated by the KX3 display) is 5 Watts...fine! Now, if I turn 
 off the KX3, plug in the 13.8 Volt source back into the KX3, and then 
power on,  output is still at 5 Watts. I have to readjust PWR to 10 Watts to get 
10 Watts  out.
 
Is that the way it's supposed to work, or am I missing a setting somewhere? 
 
Bert, N4CW/K1IMI