KX1 and K1 Battery Notes

[WD6DBM]

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 

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[Leigh L. Klotz Jr WA5ZNU]

I have had good luck lately with AA cells from PowerGenix.
They are Nickel-Zinc, and start at 1.83 volts fully charged and are
discharged at 1.8v.

With 6 of them in my KX1, the internal voltage was about 10.8 volts.

They don't have as good self discharge (about 10%/month) as the Lithium
primary cells, Eneloop or LiFePO4/Nano-phosphate, nor as good energy
density (about half at 1200mAH), but they can't be beat for internal
batteries and voltage.

They are available through Amazon, Fry's, and other such stores and
sites.  I bought two packs of 4, each of which came with a wall charger.

Leigh/WA5ZNU


On 11/02/2010 03:05 AM, eric norris wrote:

> 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
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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[AD6XY]

Thanks for this. I must get a battery pack kit for my K1. It seems a pity to have to use a PSU or external battery with it.

My K2 had the lead acid cell in it but I found that it was rather heavy. When I bought one of Roses' excellent cases for my K2 for a holiday to the US,  I replaced the battery with 10AA cells of 2500mAhr. This is much lighter and it has worked very well.with 5W output. 10W is possible but it drains the cells too fast. I did intend to use a LiPo cell but balked at the danger of charging them inside the K2. I do use the LiPo cells, but keep them outside the K2 - in one of the side pockets of the case. These have amazing performance for their weight and cost.

Mike