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Li-ion batteries for KX1 ??

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Phil Hystad-3

Li-ion batteries for KX1 ??

I have two questions regarding batteries used with KX1 in the internal battery pack.

1...has anyone used the 3.6 volt AA sized Li-ion battery in the KX1. I am thinking of a bank of six comprised of two strings in parallel. Each string is three 3.6 volt batteries in series. This gives approximately 11.4 volts or a little more (peak voltage of these cells are 4.2 volts). I presume that the battery pack might need to be reconfigured.

2...is there a consensus on the best, cost optimum versus performance, type of battery for the KX1? That is, alkaline versus, lithium (1.5 volt AA) versus anything else?

Currently I used a smallish sealed lead acid battery. But it is a little bulky.

73, phil, K7PEH

Sent from my iPad
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Chip Stratton

Re: Li-ion batteries for KX1 ??

Phil -

Someone has blogged using these cells in their KX1, if you search you should
be able to find it.

My solution has involved using LiFePO4 batteries, which are safer than the
more common LiPoly technology. Two 700 mAh 6.6 volt batteries (two 3.3v
cells in each battery) wired in series fit well within the volume occupied
otherwise by the AA battery holders. Putting the KX1 in automatic repeating
CQ mode, they give a good three hours of continuous transmitting before they
need to be recharged. A plus is that these are lighter than AA cells with
their holders, and the batteries were pretty cheap, a negative is that you
should use a balance charger to recharge them, and availability is variable.
A Cellpro Multi4 will fully recharge the pack at a 3.8 amp rate in about 25
minutes.

If this solution interests you, I posted specifics about the batteries to
the listserve last month. If you have other questions feel free to email me.

Chip

On Thu, Apr 21, 2011 at 4:40 PM, Phil Hystad <[hidden email]> wrote:

> I have two questions regarding batteries used with KX1 in the internal
> battery pack.
>
> 1...has anyone used the 3.6 volt AA sized Li-ion battery in the KX1. I am
> thinking of a bank of six comprised of two strings in parallel. Each string
> is three 3.6 volt batteries in series. This gives approximately 11.4 volts
> or a little more (peak voltage of these cells are 4.2 volts). I presume
> that the battery pack might need to be reconfigured.
>
> 2...is there a consensus on the best, cost optimum versus performance, type
> of battery for the KX1? That is, alkaline versus, lithium (1.5 volt AA)
> versus anything else?
>
> Currently I used a smallish sealed lead acid battery. But it is a little
> bulky.
>
> 73, phil, K7PEH
>
> Sent from my iPad
> ______________________________________________________________
> 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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Raymond Sills

Re: Li-ion batteries for KX1 ??

In reply to this post by Phil Hystad-3

Hi Phil:

WA3WSJ has a nice page about the KX1, and has done just what you have
in mind.

See: <http://www.wa3wsj.org/WA3WSJQRP.html>

73 de Ray
K2ULR
FN20kg
Warrington, PA

On Apr 21, 2011, at 5:40 PM, Phil Hystad wrote:

> I have two questions regarding batteries used with KX1 in the
> internal battery pack.
>
> 1...has anyone used the 3.6 volt AA sized Li-ion battery in the
> KX1. I am thinking of a bank of six comprised of two strings in
> parallel. Each string is three 3.6 volt batteries in series. This
> gives approximately 11.4 volts or a little more (peak voltage of
> these cells are 4.2 volts). I presume that the battery pack might
> need to be reconfigured.
>
> 2...is there a consensus on the best, cost optimum versus
> performance, type of battery for the KX1? That is, alkaline
> versus, lithium (1.5 volt AA) versus anything else?
>
> Currently I used a smallish sealed lead acid battery. But it is a
> little bulky.
>
> 73, phil, K7PEH
>
> Sent from my iPad
> ______________________________________________________________
> 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

Phil Hystad-3

Re: Li-ion batteries for KX1 ??

Thanks for the pointer -- I will look it up.

phil

On Apr 21, 2011, at 5:57 PM, Ray Sills wrote:

> Hi Phil:
>
> WA3WSJ has a nice page about the KX1, and has done just what you have in mind.
>
> See: <http://www.wa3wsj.org/WA3WSJQRP.html>
>
> 73 de Ray
> K2ULR
> FN20kg
> Warrington, PA
>
>
> On Apr 21, 2011, at 5:40 PM, Phil Hystad wrote:
>
>> I have two questions regarding batteries used with KX1 in the internal battery pack.
>>
>> 1...has anyone used the 3.6 volt AA sized Li-ion battery in the KX1. I am thinking of a bank of six comprised of two strings in parallel. Each string is three 3.6 volt batteries in series. This gives approximately 11.4 volts or a little more (peak voltage of these cells are 4.2 volts). I presume that the battery pack might need to be reconfigured.
>>
>> 2...is there a consensus on the best, cost optimum versus performance, type of battery for the KX1? That is, alkaline versus, lithium (1.5 volt AA) versus anything else?
>>
>> Currently I used a smallish sealed lead acid battery. But it is a little bulky.
>>
>> 73, phil, K7PEH
>>
>> Sent from my iPad
>> ______________________________________________________________
>> 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
>

WA6L

Re: Li-ion batteries for KX1 ??

In reply to this post by Chip Stratton

Hi, Phil,

I remember posting this information some time back but can't find it. So here is a summary:

I found the best solution to portable operation with the KX-1 is to use rechargeable 3.7 VDC Li Ion AA cells. You have to rewire the battery holders so that they are in parallel rather than in series. That gives you three cells in each holder at about 11.1 VDC. The power output when operating portable then approaches the same levels as when operating from a power supply.

One source of the cells is at http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=1336 . There are many other places to get them as well. You also need a charger that will accommodate the Li Ion. I did find that these cells are minutely smaller than standard AA cells. You can get them to fit snugly into the holder by putting a small blob of solder on the contacts in the battery holders (not on the batteries!).

Some KX-1 users have built charging circuitry into the KX-1, but I elected not to do so as it really complicates things. So the batteries have to be removed from the rig for recharging. But there is information on incorporating a built-in charger on the web.

Let me know if you have any questions . . .

73,

John, WA6L