[Elecraft] KX1 and K1 Battery Notes

[eric norris]

Dear Gang:

I've been playing with different battery packs for my KX1 and K1 lately, and I 
thought I would share these observations--if only for a brief break in the K3 
APF action.  


KX1:

I tested my KX1 key down with various battery packs and noted the output.  This 
was into an OHR QRP wattmeter and a dummy load.  Here are the results, in 
descending order of output:

Lithium-Ion Nanophosphate pack (4.6 AH) from Buddipole        4.3W

12v Pb Gel Cell 
5AH                                                             4.0W

Fresh Alkaline 8-cell AA 
pack                                                   3.3W

8 C Cell NiMH in spring-clip holder 5000mAH                              2.8W

Mid-life alkaline 8-cell AA pack 
spring                                      2.7W

8 cell AA NiMH spring Eneloop 2000mAH                                2.7W

8 cell AA NiMH 2650 mAH in spring loaded pack                        2.6W

Internal 6-cell pack with Lithium AA                                            
1.5 W

K1:

I originally squeezed the 2650 mAH NiMH batteries into my K1's internal holder.  
But they were always dead when I got a sudden schedule opening and good weather 
for a little QRP portable.  I replaced these with the lower-capacity 2000 mAH 
Eneloop batteries that are supposed to retain 80% of their charge for an entire 
year.  Then I attached a wattmeter and dummyload to the K1, and let it call CQ 
for two hours.  At then end of this it was still putting out 5 watts and I 
stopped the test--a couple hours of QRP portable is usually all I do.

Your mileage may vary, of course.  While looking for battery articles online I 
ran across one by a regular contributor to this list, who warned of the rather 
substantial I**2R losses from spring-loaded battery holders.  Also, I just 
received the nanphosphate pack so I haven't used it in the field.  I will report 
back later after I have some experience with it.   

72..74

Eric WD6DBM

KX1 K1 K2/10 K3/100 P3 XV144 XV432 W2x2 nearly all mini-modules and foaming for 
a KPA500.  Email me if you are looking to buy a pristine pre-MFJ AL-1200