[Elecraft] KX1 on AAAs or Lithium Polymer?

[Leigh L Klotz, Jr.]

Wayne,

I operate almost exclusively with 10 NiMH AA's and would like an 
alternate bottom that holds that, if it fits in your production plans.

I would also like an 8 cell holder for the Lithium cells.  I keep the 
Lithium primary cells in place but use them only for RX or for when I am 
using the HFPacker amp to keep from overdriving the amp.

I have Lithium Poly rechargeables I got on sale at Halted and might hook 
them up using the Batteryspace protection board, but the 11.1v is not 
atractive.  A 14.8v with a dropping diode might; I know Oliver KB6BA has 
been active in this area.

Leigh / WA5ZNU

On Fri, 25 Nov 2005 9:40 am, wayne burdick wrote:
> We've located a 4-AAA cell battery holder that would fit inside the KX1 
> (one at each end of the bottom cover, as with the present AA holders). 
> 8 cells would provide 10 or 12 volts, giving you significantly more 
> power output than 6 of the same cells (as much as 4 watts). The 
> tradeoff would be in battery life. AAA-size NiMH, alkaline and lithium 
> cells provide around 1000 to 1250 mA-hours, or around half as much as 
> similar high-capacity AA cells.
>
> Another option would be to use a small lithium polymer battery. 11 
> volts at up to 1450 mA-hours or so might be possible, although these 
> batteries are very expensive. AAAs might be preferable in a pinch 
> because you can buy them anywhere. In the field, you can borrow 
> triple-As from flashlights or other portable electronic devices. The 
> difference in weight between 8 triple As and a LiPo battery is probably 
> only couple of ounces, so weight is not likely to be the primary 
> criteria.
>
> You'd probably get five to eight hours of casual operation with NiMH, 
> LiPo, or lithium cells, which are preferable to alkalines because of 
> their flat discharge curve. Of course you could recharge NiMH or LiPo 
> cells in the field with a small solar panel. (Has anyone tried using 8 
> AAA cells with the KX1?)
>
> We could (in theory) create a new bottom cover option for the KX1 that 
> would include two 4-cell AAA holders or a LiPo battery, plus a charge 
> controller that would run from the KX1's DC input jack. The battery 
> holders and charge controller components could be soldered to a thin 
> PCB module that runs the full length of the bottom cover. In the case 
> of AAAs, we'd include a switch to select rechargeable or 
> non-rechargeable batteries. You might be able to recharge while 
> operating, although this would have to be tested, since some charge 
> controller generate significant noise.
>
> Any input on such a product would be appreciated. If there were 
> significant interest, we'd try to have it ready early next year.
>
> 73,
> Wayne
> N6KR