[Elecraft] KX1 External LiIon Battery

[W0rw at aol.com]

KX1 Battery Pack.
   i also have an external 4 cell LiIon battery pack for my KX1. You could 
just use 3 cells to get 12.4V, which is more than the internal primary Lithium's 
normally provide. The radio has power diode inputs so it will draw current 
from which ever battery has the higher voltage (internal or external).
   i wanted more power for /pm operation so i built a LiIon pack with 4 Sony 
18650's (1.5 AH) cells to give me 16.7 V, (do this at your own risk, it voids 
the warranty). Then i use 2 diodes to drop the voltage down to 14V (which is 
the maximum rating for the KX1) and this gives full output on transmit. The 
voltage goes up to 15V on receive but there is apparently no damage. i switch the 
diodes out of the circuit as the battery voltage and my power output drops. 
The transmit voltage is down to about 14.0V after a few hours. The controller 
for these cells disconnects at 10.0V.
This 4 cell LiIon battery pack weighs 7 ounces. 10 AA NiCad's weigh about the 
same but have 1/3 the capacity.

Paul  w0rw