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
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