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KX1 on AAAs or Lithium Polymer?

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wayne burdick

KX1 on AAAs or Lithium Polymer?

Administrator

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

---

http://www.elecraft.com

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Simon (HB9DRV)

Re: KX1 on AAAs or Lithium Polymer?

Think about a portable battery pack which the sub-zero operator can keep in
an inside pocket. This pack supports 8 or (better) 10 x AA Ni-MH. This gives
us 2800 mAH @ 12v. The case should be rugged. You could add a battery status
indicator - the Elecraft junkies would then have another kit they can buy
(the BAT1 kit)!

Then of course there's solar inputs to run in parallel - would be very
handy!

Simon Brown
---
www.hb9drv.ch www.laax.ch

----- Original Message -----
From: "wayne burdick" <[hidden email]>

> Any input on such a product would be appreciated. If there were
> significant interest, we'd try to have it ready early next year.

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W0rw

Re: KX1 on AAAs or Lithium Polymer?

In reply to this post by wayne burdick

i am still using NiCad's...in my KX1.
KX1 - 1/2AA NiCad Battery Modification...Rev. D.

Originally i had 6 'AA' NiCad batteries in the KX1 but i needed more power
for pedestrian mobile operation.
i removed 4 of the 'AA' NiCad batteries and added 8 - 1/2'AA'-250's (short
type AA) to boost the voltage to 14 VDC. That raises the output power to 3 Watts.
The operating time is about 3 hours on a full charge (depending on your code
speed and number of "Q's)..
These batteries are available from Batteries Plus.
(After these batteries age, they will have slightly lower terminal voltage,
then you can add 2 additional 1/2 AA batteries; i started with 8 and now i am
using 10 - 1/2 AA-250's and one full sized AA NiCad, still keeping the voltage
at or below the KX1 maximum of 14V. So be sure to buy a few extra 1/2 AA's).
The 1/2 AA's have flat contacts so they need to have a little solder blob
added to the + terminal so they will touch each other when in series in the
battery holder.
These 1/2 AA 'short' batteries (250 mAH) are 7/8 inch long. (There is a lon
ger 1/2 'AA' battery that is 1.2 inches long but it won't fit the battery
holder).
Note: These NiCad batteries weigh 4 oz and the Enegerizer L91's also weigh 4
oz. The capacity of the Energizer L91 non-rechargeable battery is 2.9 AH (at
1.0V discharge voltage) and the Rechargeable NiCad gives 0.25 AH, thats only
about 9% of the L91 capacity, but it's still very practical.
Pictures of the NiCad batteries are on the HFPack2 Yahoogroup web site.

See: http://photos.groups.yahoo.com/group/hfpack2

You will have to log in to see the pictures..

Look in the 'Photos' area, Page 2, and in the 'W0RW-Paul' folder.
ps: If you make any modification to your KX1 it will void the warranty...
---------------
Here is a how you can charge the internal NiCad's without taking the KX1
cover off.
(This is not suggested if you are going to use only the primary L91 Li
batteries).

i installed a small 2.5 mm mono phone jack with a NC switch to the lower
corner of the battery chassis. You have to drill hole in the chassis.
The jack goes right below the auxiliary DC connector J1.

Note: For the J1 power switching modification to work correctly this
jack must be isolated from the chassis. That requires a few mica or thin
fiber washers and a small piece of tubing, or a flanged insulating washer.
This jack has a NC switch built into it so when you plug in the charging plug
the internal NiCad batteries are disconnected from the radio and the charging
voltage is applied to the batteries even if the radio is turned on.
The battery pack wiring connection changes are: black wire to the new
charging jack ground pin, red wire to the jack center pin and the normally closed
switch wire goes to the red wire of J5-1.

Now you can operate the KX1 from the auxiliary DC connector while
simultaneously charging the internal NiCad batteries through the new charging jack.

You can also monitor the battery voltage through this connector or
when not charging the battery, The battery voltage can be displayed by
pressing "RIT" and "Band" simultaneously, Twice.
The charger can be made from any wall transformer that puts out about 18VDC
open circuit.
The charging current for the 1/2AA NiCad batteries should be set for 50 ma
for 5 hours. You can add a switch to the charger and add an additional resistor
to give 10ma for trickle charging. If you leave the KX1 NiCads on trickle
charge it will always be ready to go.
You will need to insert an appropriate resistor in series with the
transformer to limit the charging current. (If you change the number of batteries in the
unit you will have to re-adjust the charging current).
---------
Here is the KX1 Battery Switching Modification:
The original power distribution design "AND's" the internal battery and
external battery sources together using 2 diodes.
If your external battery voltage goes below the internal battery
voltage, the internal batteries will start draining.
i left my KX1 on for a few days and after i ran down the external battery and
the internal batteries took over and became discharged.
These were the expensive Lithium "AA" Primary batteries (L91's).
i wanted to save the use of these Li batteries for special uses
like Pedestrian Mobiling: See the w0rw/pm KX1 report on the Adventure Radio
Society web site at:
http://www.arsqrp.com/ars/pages/back_issues/2004_text/0204_text/W0RW.html

Here are the details of the DC J1 switching Modification:
The Elecraft DC Power connector has an unused (normally closed) switch.
This modification will use that switch so that when an external power source
is connected the internal batteries will be disconnected, and conversely when
the DC power plug is removed the internal batteries will be reconnected.
Open the unit on an ESD grounded work station.
Separate the battery compartment by pulling the battery connector (J1) out.
Cut the 2 traces that ground P1-2 "-" (getting scary now)...Top Side..
Now add an insulated jumper wire from P1-2 "-" to the side contact of J1 (J1
is the power connector), The unused switch contact is soldered to an isolated
pad just the left of the marking 'Z2'...
That's it....
Now you can protect those internal batteries.
One other thing that you can do is to set the LED Display Control to "INF"
then the LED display will act as a pilot light.
72 de w0rw
Paul [hidden email]

Paul Signorelli [hidden email]
P.O. Box 6069
Colorado Springs, CO 80934

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Leigh L. Klotz Jr WA5ZNU

Re: KX1 on AAAs or Lithium Polymer?

Administrator

In reply to this post by wayne burdick

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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Andrea Borgia

Re: KX1 on AAAs or Lithium Polymer?

In reply to this post by wayne burdick

wayne burdick wrote:

> Any input on such a product would be appreciated. If there were
> significant interest, we'd try to have it ready early next year.

LiPo would be nice, for me: I am already using NiMH in the standard
cover and given my typical operating situation having 8 cells instead of
6 isn't worth the expense.

This assuming I manage to save something to buy it, of course ;-)

B73,
Andrea.

--
Homepage: http://andrea.borgia.bo.it / Amateur radio: IZ4FHT
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Darrell Bellerive

Re: KX1 on AAAs or Lithium Polymer?

In reply to this post by wayne burdick

A rechargeable battery system with a built in charger would have it's appeal
especially if it can be charged from many different sources such as 110/120
VAC 60Hz, 220/240 VAC 50 Hz, 12 or 24 volt automobile cigarette lighter
sockets, solar power, etc. If Braun can do it with a razor, just think how
much better Elecraft could design it.

While your updating the KX1 how about adding receive capability down to to 3.2
Mhz. This would allow listening to the 60, 75, and 90 meter shortwave
broadcast bands as well as the 80 and 60 meter amateur bands. :-)

Darrell
VA7TO

On November 25, 2005 09:41 am, wayne burdick wrote:

> 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
>

--
Darrell Bellerive
Amateur Radio Stations VA7TO and VE7CLA
Grand Forks, British Columbia, Canada
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PA0NCV

Re: KX1 on AAAs or Lithium Polymer?

In reply to this post by wayne burdick

I would be really interested in the 8 triple A's NiMH with a charge
controller.
This with a an extra backpanel would make it easy to choose between time and
power.

73
Nick
PAØNCV

> 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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Gil Stacy

Re: KX1 on AAAs or Lithium Polymer?

LiPoly batteries are expensive, lightweight and very dangerous if improperly
charged. When things go bad with LiPolies, things can go very bad. I have
started using them on my ATS3. Here's a list of do's and don'ts regarding
LiPolies and a photo of what happens when the dont's are violated.
http://www.rcgroups.com/forums/showthread.php?t=209187 Can you imagine this
happening in your KX1? ;)

73, Gil NN4CW
K2 3104; KX1 53

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Michael Bower N4NMR

RE: KX1 on AAAs or Lithium Polymer?

Wow, from what I (briefly) saw at that link, why would anyone want to use
LiPos? Yes, they may provide some advantages but the disadvantages/risks
would certainly (in my mind) overwhelm the advantages.

Just my .02.

Michael N4NMR

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Gil Stacy
> Sent: Saturday, November 26, 2005 8:26 AM
> To: [hidden email]; [hidden email]
> Subject: Re: [Elecraft] KX1 on AAAs or Lithium Polymer?
>
>
>
> LiPoly batteries are expensive, lightweight and very
> dangerous if improperly charged. When things go bad with
> LiPolies, things can go very bad. I have started using them
> on my ATS3. Here's a list of do's and don'ts regarding
> LiPolies and a photo of what happens when the dont's are violated.
> http://www.rcgroups.com/forums/showthread.php?t=209187 Can
> you imagine this happening in your KX1? ;)
>
> 73, Gil NN4CW
> K2 3104; KX1 53
>
>
> _______________________________________________
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>
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Gil Stacy

RE: KX1 on AAAs or Lithium Polymer?

Wow, from what I (briefly) saw at that link, why would anyone want to use
>LiPos? Yes, they may provide some advantages but the disadvantages/risks
>would certainly (in my mind) overwhelm the advantages.

LiPos are like gasoline, both can be very dangerous but with proper use and
caution, the risk is minimized.

73, Gil NN4CW

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W0rw

Re: KX1 on AAAs or Lithium Polymer?

In reply to this post by wayne burdick

Hi Michael.
i do have a LiIon Hard Carbon external battery pack but i would not
use Li Polymers in my pocket because of the fire hazards.
i use 10 1/2 "AA" (250mAH) plus one regular "AA" NiCad in my KX1.
Send me an email and i will send you the modification details.
The KX1 is usually hand held so the batteries stay warm.
Paul [hidden email]
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k6dgw

Re: KX1 on AAAs or Lithium Polymer?

In reply to this post by wayne burdick

One Ham's Experience: Good News: The LiPoly I got (local RC hobby
shop) was just great! I did not deplete it on our cruise thru the
Panama Canal, maybe 6 hours operating time (mostly listening and no
CQ's), but I did rag chew a bit with a number of SA stns. Ran a Spartan
Sprint after return without recharging just to see if I could. Voltage
stayed nearly constant until full discharge, at which point it dropped
quickly. As quickly, I recharged it on a MAHA 77.

Bad News: It worked again very well in the next Spartan. Then I got
busy, and didn't check it for perhaps 5 months. At N6A (Alpine County,
CQP), I tried it our before the contest, and it was toast. They are
extremely light (a factor in Spartan, but I wonder in a back pack), they
seem good, but they are expensive, and I've heard they die in a year or
so, regardless of how you use them.

WAYNE: To your basic questions -- I wouldn't spend much (or any) time
adapting the KX1 to LiPo. Mine came with tinned leads on which I put a
coax plug. The expense is a real downer. The difference in power
between 6 and 8 AA NiMH's seems minimal. Yes, Alkaline dry cells do
have a non-flat discharge curve, but you can get an bunch of them at
Costco or Sam's and they're what I generally use. I think the weight of
the additional batteries is overshadowed by the weight of the solar
panel and regulator for those who really do back-pack (I did but I don't
anymore -- too old).

I know you have to keep up with technology and the ever-increasing
demand for "one more feature," but I would caution against messing
around with a success, which my KX1 is right now. Besides, we're
"amateurs," and you have to leave us something to mess around with!

73,

Fred K6DGW
Auburn CA CM98lw

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

Jim Sheldon

RE: KX1 on AAAs or Lithium Polymer?

Another's experience.
I haven't tried the LiPoly batteries yet, but I did find a fairly decent
bargain on NiMH batteries & charger at one place. They are made in China,
but the quality seems okay. Got 20 (count 'em) 20 2300 MaH AA batteries and
a charger that holds 10 at a time for about 50 bucks. The charger is unique
in that it works off a 12 volt wall wart @ 800 ma, and the charger contains
microprocessor controllers for each slot so it will charge the cells in
multiples of one. That's right you can charge 1 or 2 or 3 or any number up
to 10 at a time, and the negative contact is spring loaded with a lot of
travel so it will charge either AA or AAA type batteries, and the charge
controller is smart enough (according to the very sketchy book) to handle
either type and either NiCD or NiMH batteries. Each slot has an LED
indicator that is red when charging and goes green when the cell is fully
charged.

I bought a flat 10 AA cell pack from Mouser for a couple of bucks and added
a coax power plug on a short lead to it. Gives me 12 volts @ 2.3AH in a
reasonably light package, not to mention it was pretty cheap as these things
go.

I think the name of the place I got the batteries/charger was
batteryspot.com or some such. I don't remember, for sure. The verdict is
still out on battery/charge life, but I'll report any further
positive/negative info when it happens here.

Jim - W0EB
KX1 #1268

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Fred Jensen
> Sent: Saturday, November 26, 2005 9:06 PM
> To: Elecraft Reflector
> Subject: Re: [Elecraft] KX1 on AAAs or Lithium Polymer?
>
>
> One Ham's Experience: Good News: The LiPoly I got (local RC hobby
> shop) was just great! I did not deplete it on our cruise thru the
> Panama Canal, maybe 6 hours operating time (mostly listening and no
> CQ's), but I did rag chew a bit with a number of SA stns.
> Ran a Spartan
> Sprint after return without recharging just to see if I
> could. Voltage
> stayed nearly constant until full discharge, at which point
> it dropped
> quickly. As quickly, I recharged it on a MAHA 77.
>
> Bad News: It worked again very well in the next Spartan. Then I got
> busy, and didn't check it for perhaps 5 months. At N6A
> (Alpine County,
> CQP), I tried it our before the contest, and it was toast. They are
> extremely light (a factor in Spartan, but I wonder in a back
> pack), they
> seem good, but they are expensive, and I've heard they die in
> a year or
> so, regardless of how you use them.
>
> WAYNE: To your basic questions -- I wouldn't spend much (or
> any) time
> adapting the KX1 to LiPo. Mine came with tinned leads on
> which I put a
> coax plug. The expense is a real downer. The difference in power
> between 6 and 8 AA NiMH's seems minimal. Yes, Alkaline dry cells do
> have a non-flat discharge curve, but you can get an bunch of them at
> Costco or Sam's and they're what I generally use. I think
> the weight of
> the additional batteries is overshadowed by the weight of the solar
> panel and regulator for those who really do back-pack (I did
> but I don't
> anymore -- too old).
>
> I know you have to keep up with technology and the ever-increasing
> demand for "one more feature," but I would caution against messing
> around with a success, which my KX1 is right now. Besides, we're
> "amateurs," and you have to leave us something to mess around with!
>
> 73,
>
> Fred K6DGW
> Auburn CA CM98lw
>
>
> 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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Jim Sheldon

RE: KX1 on AAAs or Lithium Polymer?

In reply to this post by k6dgw

Addition -- I had the battery vendor wrong - batteryspace.com not
batteryspot -- usual disclaimer, not connected to them in any way, just
reasonably satisified with their product. They have a bunch of different
battery/charger combo's.

W0EB

Another's experience.
I haven't tried the LiPoly batteries yet, but I did find a fairly decent
bargain on NiMH batteries & charger at one place. They are made in China,
but the quality seems okay. Got 20 (count 'em) 20 2300 MaH AA batteries and
a charger that holds 10 at a time for about 50 bucks. The charger is unique
in that it works off a 12 volt wall wart @ 800 ma, and the charger contains
microprocessor controllers for each slot so it will charge the cells in
multiples of one. That's right you can charge 1 or 2 or 3 or any number up
to 10 at a time, and the negative contact is spring loaded with a lot of
travel so it will charge either AA or AAA type batteries, and the charge
controller is smart enough (according to the very sketchy book) to handle
either type and either NiCD or NiMH batteries. Each slot has an LED
indicator that is red when charging and goes green when the cell is fully
charged.

I bought a flat 10 AA cell pack from Mouser for a couple of bucks and added
a coax power plug on a short lead to it. Gives me 12 volts @ 2.3AH in a
reasonably light package, not to mention it was pretty cheap as these things
go.

I think the name of the place I got the batteries/charger was
batteryspot.com or some such. I don't remember, for sure. The verdict is
still out on battery/charge life, but I'll report any further
positive/negative info when it happens here.

Jim - W0EB
KX1 #1268

Alan WB6ZQZ

Re: KX1 on AAAs or Lithium Polymer?

In reply to this post by wayne burdick

Lithium Polymer and Lithium Ion batteries are used in many millions of
cellphones, cameras, PDAs, laptops, etc., etc. every day. These batteries
MUST NOT be OVERCHARGED or OVERDISCHARGED. The proper charger will solve
this problem, and protection circuits also can even prevent overdischarge
by disconnecting the load. These circuits are common in industry with these
batteries.

Laptop, PDA, camera and cellphone batteries last a lot more than one year,
as an example. Life expectancy is more like 3 years or better. It depends
on many factors including the number of charge/discharge cycles.

Lithium chemistry batteries have very low self-discharge. If disconnected
from any loads they typically maintain most of their charge over many
years. For this reason they are far superior to other rechargeable
technologies when it comes to 'readiness' after sitting in storage. They
can also be maintained in standby charging mode, which often tends to kill
other battery technologies.

I put a set of LiPo batteries into my K2 over a year ago and they are still
charged and operating even though I've ignored them for almost a year. I
have not used them a great deal, but they do hold their charge very well if
disconnected. I always make sure I turn off the battery disconnect switch
at the rear of the K2 when shutting it down. Details of my installation
follow at the link below.

http://www.qsl.net/wb6zqz/k2/lipo_batteries.html

One day I had a discussion with Wayne (of Elecraft) regarding LiPo
batteries, and I don't expect to see anything like that from Elecraft
anytime soon.

The safest way to deal with Lithium Polymer batteries is to have a
protection circuit packaged with the battery pack. This circuit prevents
over and undercharging. These circuits are commercially available. They use
low-loss FETs rather than diodes. Make sure they allow the high current
drain required for your application.

-- Alan wb6zqz

At 07:06 PM 11/26/2005, Fred Jensen wrote:

>One Ham's Experience: Good News: The LiPoly I got (local RC hobby shop)
>was just great! I did not deplete it on our cruise thru the Panama Canal,
>maybe 6 hours operating time (mostly listening and no CQ's), but I did rag
>chew a bit with a number of SA stns. Ran a Spartan Sprint after return
>without recharging just to see if I could. Voltage stayed nearly constant
>until full discharge, at which point it dropped quickly. As quickly, I
>recharged it on a MAHA 77.
>
>Bad News: It worked again very well in the next Spartan. Then I got busy,
>and didn't check it for perhaps 5 months. At N6A (Alpine County, CQP), I
>tried it our before the contest, and it was toast. They are extremely
>light (a factor in Spartan, but I wonder in a back pack), they seem good,
>but they are expensive, and I've heard they die in a year or so,
>regardless of how you use them.
>
>WAYNE: To your basic questions -- I wouldn't spend much (or any) time
>adapting the KX1 to LiPo. Mine came with tinned leads on which I put a
>coax plug. The expense is a real downer. The difference in power between
>6 and 8 AA NiMH's seems minimal. Yes, Alkaline dry cells do have a
>non-flat discharge curve, but you can get an bunch of them at Costco or
>Sam's and they're what I generally use. I think the weight of the
>additional batteries is overshadowed by the weight of the solar panel and
>regulator for those who really do back-pack (I did but I don't anymore --
>too old).

K. Rice

Re: KX1 on AAAs or Lithium Polymer?

In reply to this post by wayne burdick

My experiences are with K1, not KX1 but may generalize if I can
manage to keep the form factor in mind. Also I use 18650 Li-Ion
cells but use figures for 14500 cells below, as 18650s are too
big for this application.

As others have mentioned, these cells require a specialized
charge-discharge regime. For that reason I don't put Li-Ion
cells inside radios, but I might if Wayne designed the charge
controller. :)

For the KX-1, 14500 series (AA-size) cylindrical Li-Ion cells should
work nicely in 3S2P configuration with a protection IC/PCB for
each of the two AA-size 3-packs to prevent overcharge/overdischarge
and non-uniform charge distribution across cells. (As others have
mentioned, the latter is a problem with Li-Ion cells that can
lead to catastrophic failure).

3S2P configuration gives 11.1 volt nominal at 1500 mAh. Peak
voltage is 12.3-12.6 volts depending on how they're charged,
and it stays above 11.1 volts for a good long time ... 3 hours,
say, with casual operating. The IC/PCB sheds the load when
per-cell voltage drops to 2V, insuring long life and long-term
rechargeability.

Weight is around 4.8 oz and the new pack wouldn't require more
and hence smaller cells (e.g. AAA-size) than the original design,
presumably reducing the cost of a redesign.

Cost is about 1/2 of equivalent Li-poly. Li-poly saves a little
over 2 oz in weight, but some of the saving will be offset by
the need for additional packaging to protect the fragile poly
flat-pack.

I fuse my pack at 2A and keep it in a plastic project box with
a panel-mount PowerPole connector.

I get this stuff from batteryspace.com - usual disclaimer applies.

73
Ken K3VV

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