Need suggestion for K1 external rechargeable battery

[George Averill]

I have been powering my K1 with a 15 AH battery that I had on hand.  Much too heavy for a back pack HI!  I'm looking for a small, light weight, rechargeable battery.  What AH battery should I be looking for if operating at 5W?  Any suggestions?

George

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[k6dgw]

On 3/7/2012 6:52 PM, George Averill wrote:
> I have been powering my K1 with a 15 AH battery that I had on hand.
> Much too heavy for a back pack HI!  I'm looking for a small, light
> weight, rechargeable battery.  What AH battery should I be looking
> for if operating at 5W?  Any suggestions?

Hard to beat the LiFePO4 chemistry.  I use an A123 4S1P with my K2.
Upsides:  Very flat discharge curve, mine starts at about 14V, declines
to about 12.9 very quickly and pretty much stays there until it's dead,
at which point the voltage falls very quickly.  Small, mine measures
about 2 3/4" x 4 1/4" x 1" and weighs less than a pound.  On CW, at 5W,
with a reasonable duty cycle [calling CQ, tuning, answering] it powers
my K2 longer than I'm willing to sit on a SOTA summit [7-8 hours].  K2
RX drain is 280ma, it'll power it RX only for 15-20 hours easy.

Downsides:  They're not exactly cheap, and you need a cell balancing
charger for them.  I use a CellPro which has programs for every other
battery known to humankind too.  Be sure to fuse the + power to the
radio.  These batteries will deliver well over 15C into a short ...
things get real hot real fast.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2012 Cal QSO Party 6-7 Oct 2012
- www.cqp.org

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[Mike Morrow-3]

George wrote:

> I have been powering my K1 with a 15 AH battery that I had on hand...
> I'm looking for a small, light weight, rechargeable battery.  What
> AH battery should I be looking for if operating at 5W?

For more than ten years, I've used a sealed lead-acid battery of 4 to 5
Ah capacity.  It's low-cost, not too heavy, not too big, and has it
has plenty of capacity for several days operation.  For a backup/reserve
supply, I use a ten-cell AA-pack with NiMH cells.  The SLA battery is
far less problematic and much more reliable than the NiMH pack.

Here's a page full of the SLA batteries similar to what I use:

 http://www.atbatt.com/sealed-lead-acid-batteries/b/yuasa/m/12v-4ah.asp

73,
Mike / KK5F
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[Mike WA8BXN]

George,
 
I think more information is needed. How long do you want to be able to run
the K1 before recharging? What is your transmit to receive time ration? How
important is having a battery that fits in the radio? How many times per
year will you really be using the radio with the battery for power?
 
 
It could be that non-rechargeable batteries are your best choice.
 
73 - Mike WA8BXN
 
 
-------Original Message-------
From: George Averill
Date: 3/7/2012 10:05:39 PM
To: [hidden email]
Subject: [Elecraft] Need suggestion for K1 external rechargeable battery
 
I have been powering my K1 with a 15 AH battery that I had on hand. Much too
heavy for a back pack HI! I'm looking for a small, light weight,
rechargeable battery. What AH battery should I be looking for if operating
at 5W? Any suggestions?
 
George
 
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[Brian Hunt]

I've been using a Power Sonic PS-1229 2.9 Ah SLA.  It gives me plenty of
power for an afternoon of operating the K1 in a normal rag chew mode.  
The PS-1229 is a convenient shape: 7 x 1.3 x 2.5 inches and weighs about
half again more than the K1.  I bought mine used at a swap meet for a
few bucks.  You should be able to find a new one on the web for around $15.

Brian
K0DTJ

On 3/7/2012 6:52 PM, George Averill wrote:

> I have been powering my K1 with a 15 AH battery that I had on hand.  Much too heavy for a back pack HI!  I'm looking for a small, light weight, rechargeable battery.  What AH battery should I be looking for if operating at 5W?  Any suggestions?
>
> George
>
> ______________________________________________________________
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>

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[Richard-3]

If hiking is your issue, you might want to consider a LiPO battery like
ones used by model helecopter inthusiasts.  I've been using a 950 mAH
Blue LiPO for several months, once a week for a 1-1.5 hour morse code
practice.  I've been expecting it to run dry, but I have not recharged
it yet.  I have not had a timer on it, but would suspect I have at least
6 hours on the battery, running a K1 at 1W.

I went this route on advice from a SOTA operator who wants extreme low
weight.  Battery weighs about 65 grams.  You do need a special charger.  
Battery costs around $6-10.  Charger/balencers run $20-40.

OK, I also bought a 2200 mAH battery for a backup.

Rich
NU6T

On 3/8/2012 9:39 AM, B Hunt wrote:

> I've been using a Power Sonic PS-1229 2.9 Ah SLA.  It gives me plenty of
> power for an afternoon of operating the K1 in a normal rag chew mode.
> The PS-1229 is a convenient shape: 7 x 1.3 x 2.5 inches and weighs about
> half again more than the K1.  I bought mine used at a swap meet for a
> few bucks.  You should be able to find a new one on the web for around $15.
>
> Brian
> K0DTJ
>
> On 3/7/2012 6:52 PM, George Averill wrote:
>> I have been powering my K1 with a 15 AH battery that I had on hand.  Much too heavy for a back pack HI!  I'm looking for a small, light weight, rechargeable battery.  What AH battery should I be looking for if operating at 5W?  Any suggestions?
>>
>> George
>>
>> ______________________________________________________________
>> Elecraft mailing list
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>>
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>> Please help support this email list: http://www.qsl.net/donate.html
>>
>>
> ______________________________________________________________
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>
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>
>

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