[Elecraft] K2 Internal Battery Option

[Dave G4AON]

Jim

I've had the internal battery pack in my K2 almost since day one (back 
in 2001). The whole package feels like it's filled with bricks once you 
put the battery in, it certainly stays where it's placed on the shack 
bench. I've operated QRP CW for a day on the internal pack without 
issues, however gel cells will become downgraded if deeply discharged on 
a regular basis... The good news is they aren't very costly items to 
replace every couple of years or so. With the internal pack you need 
more than the normal 13 to 13.8 Volts from your bench power supply to 
charge it, I tweaked the output voltage on my 3 Amp bench power supply 
to 14.2 Volts. If you use the DSP, SSB and other additions to the K2, 
these will erode the endurance while operating from the internal battery 
pack. The operating time in the KBT2 manual is based on the K2 drawing 
150 mA on receive, mine is reading 200 mA more than that (it includes 
SSB, ATU, 160m and DSP).

An external gel cell would need a dedicated sealed lead acid battery 
charger, they are available from many hobby electronic shops, or there 
was an article in the ARRL hand books showing how to make one.

73 Dave, G4AON