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Good Battery for K3 Portable Ops

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Paul Grigorieff

Good Battery for K3 Portable Ops

I would appreciate knowing the experiences of folks who have run their K3 on battery power for several (4-8?) hrs., with perhaps a 20% TX duty cycle. What types and sizes of batteries seem to be the best balance of staying power and portability?

-Paul Grigorieff, N1HEL
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Bruce Beford-2

Re: Good Battery for K3 Portable Ops

Paul,
you will get more meaningful replies if you state what power level for TX.
Are you asking about a 10W K3, or 100W version?

73
Bruce
N1RX

> I would appreciate knowing the experiences of folks who have run their K3
> on battery power for several (4-8?) hrs., with perhaps a 20% TX duty
> cycle. What types and sizes of batteries seem to be the best balance of
> staying power and portability?

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Don Wilhelm-4

Re: Good Battery for K3 Portable Ops

In reply to this post by Paul Grigorieff

Paul,

You did not say whether that is a K3/10 or K3/100 and whether you have
the extra current draw of the subRX, nor what your transmit power level
would be, so we cannot give you a realistic answer.
If you are backpacking, you will want the least weight, but if you are
going to a picnic table from your vehicle and have a hand-truck to carry
the battery, I use a 75 ampere-hr AGM battery. If I have to carry the
batteries in my hand, I operate at 10 watts or less and use a couple of
7AH Gel Cells (SLA). I like the reliability and safety of SLA
technology despite its heaver weight than more modern battery technologies.

73,
Don W3FPR

On 8/12/2013 5:36 PM, PGrig wrote:

> I would appreciate knowing the experiences of folks who have run their K3 on battery power for several (4-8?) hrs., with perhaps a 20% TX duty cycle. What types and sizes of batteries seem to be the best balance of staying power and portability?
>
> -Paul Grigorieff, N1HEL
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W6ODJ

Re: Good Battery for K3 Portable Ops

In reply to this post by Paul Grigorieff

Hi Paul,

I run my K3 at 100 watts out using a 35 Ah SLA battery. (Powersonic PS-12350NB) I chose that size because it is about the heaviest one I can lift easily. I have run it for hours, in fact have never been able to run it down. Good idea to get a Powersonic charger that matches the battery, too. The service life of the battery is extended if you keep it topped up. Another nifty accessory is an N8XJK Marine Booster that goes between your battery and your rig. It outputs 14.1 V so long as the battery voltage is above some preset value --- I use 11 V.

--Oliver
W6ODJ

On 12 Jan. 2013, at 14:36 PM, PGrig <[hidden email]> wrote:

W4SK

Re: Good Battery for K3 Portable Ops

Strictly depends on the power level you intend to run. I ran my KX3 at 5w
for all of Field Day, and for a two-day camping trip last weekend without
charging in between. It's a "K2 Energy" lithium ion and weighs just a few
ounces. Couldnt be happier with it. After 4 days of off-on operating,
still produces 12.4 volts.

YMMV.

-73- de W4SK

>
>> I would appreciate knowing the experiences of folks who have run their K3
>> on battery power for several (4-8?) hrs., with perhaps a 20% TX duty
>> cycle. What types and sizes of batteries seem to be the best balance of
>> staying power and portability?
>>
>> -Paul Grigorieff, N1HEL
>> ______________________________________________________________
>> 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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RobertG

Re: Good Battery for K3 Portable Ops

I'm curious what you mean by a "K2 energy" lithium ion [battery]. Please
elaborate.

...robert

On 8/12/2013 22:12, W4SK wrote:

> Strictly depends on the power level you intend to run. I ran my KX3 at
> 5w for all of Field Day, and for a two-day camping trip last weekend
> without charging in between. It's a "K2 Energy" lithium ion and weighs
> just a few ounces. Couldnt be happier with it. After 4 days of off-on
> operating, still produces 12.4 volts.
>
> YMMV.
>
> -73- de W4SK
>

--
Robert G Strickland, PhD ABPH - KE2WY
[hidden email]
Syracuse, New York, USA
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W4SK

Re: Good Battery for K3 Portable Ops

http://www.rakuten.com/prod/k2-energy-k2b12v10e-12v-10ah-lithium-iron-phosphate-battery/251299102.html?listingId=292990708

________________________________
John T. Gwin
[hidden email]
[hidden email]
----- Original Message -----
From: "Robert G Strickland" <[hidden email]>
To: <[hidden email]>
Sent: Monday, August 12, 2013 5:41 PM
Subject: Re: [Elecraft] Good Battery for K3 Portable Ops

> I'm curious what you mean by a "K2 energy" lithium ion [battery]. Please
> elaborate.
>
> ...robert
>
> On 8/12/2013 22:12, W4SK wrote:
>> Strictly depends on the power level you intend to run. I ran my KX3 at
>> 5w for all of Field Day, and for a two-day camping trip last weekend
>> without charging in between. It's a "K2 Energy" lithium ion and weighs
>> just a few ounces. Couldnt be happier with it. After 4 days of off-on
>> operating, still produces 12.4 volts.
>>
>> YMMV.
>>
>> -73- de W4SK
>>
>
> --
> Robert G Strickland, PhD ABPH - KE2WY
> [hidden email]
> Syracuse, New York, USA
> ______________________________________________________________
> Elecraft mailing list
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> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2013.0.3392 / Virus Database: 3211/6571 - Release Date: 08/12/13
>

W4SK

Re: Good Battery for K3 Portable Ops

In reply to this post by RobertG

http://www.amazon.com/Energy-K2B12V7EB-Lithium-Phosphate-Battery/dp/B0056BXE6A/ref=sr_1_2?ie=UTF8&qid=1376347621&sr=8-2&keywords=K2+Energy

________________________________
John T. Gwin
[hidden email]
[hidden email]
----- Original Message -----
From: "Robert G Strickland" <[hidden email]>
To: <[hidden email]>
Sent: Monday, August 12, 2013 5:41 PM
Subject: Re: [Elecraft] Good Battery for K3 Portable Ops

RobertG

Re: Good Battery for K3 Portable Ops

In reply to this post by RobertG

Thanks for all replies.
I'm looking for a lithium iron [etc] battery that will fit inside my K2.
I have found some that will fit - or so it seems - but none of them use
all the available space, and as a result, are less powerful than might
be had if all the space is used. Of course, external batteries are no
problem. Some comment, as do I, that I'd like a battery to fit inside
the K2 for grab and run applications. The Elecraft SLA is nice, but as
I'm sure the top honchos would admit, battery technology has moved on. I
think that 10ah can fit if the form factor is right. I've thought of
buying individual cells and assembling something, but at this point in
my much-reduced-parts-bin life, I'd just as soon buy something. Does
anyone have any experience with installing a LiPoFe "in" the K2? That
would be interesting.

...robert

On 8/12/2013 22:41, Robert G Strickland wrote:

k6dgw

Re: Good Battery for K3 Portable Ops

On 8/12/2013 4:25 PM, Robert G Strickland wrote:
> Thanks for all replies.
> I'm looking for a lithium iron [etc] battery that will fit inside my K2.

Lots of lithium battery chemistries out there. I strongly recommend NOT
putting an Li Polymer battery inside anything that costs multi-hundreds
of dollars. To begin with, they take specialized chargers, and they're
not the stablest of batteries.

Just one opinion, supported by some experience. :-)

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2013 Cal QSO Party 5-6 Oct 2013
- www.cqp.org

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Dominic Baines-3

Re: Good Battery for K3 Portable Ops

In reply to this post by Paul Grigorieff

On 12/08/13 22:36, PGrig wrote:

Largest charge 12V (13.8V normally) lead acid battery you can carry :-)

If you are running 100W then anything less than a 75-80 AH will run flat
very fast and even they will only last about 2-3 hours if fully charged
and when you drain them to <50% the power will out will not be stable
towards the end and the battery voltage might drop and you might damage
the battery so do not work expecting to get the whole charge from a battery.

I run KX3 off a 7AH at 5W out for about 3.5 hours without any issue. K3
current draw will be a bit more than that whilst qrp. This is SSB mostly
and about 40% TX duty. If I can get a car battery 75AH it will last all
day and well into the night.

Best option really is figure out what YOU need, everyone going to try /P
should really do this anyway ... monitor your current draw into the rig
(your K3) and anything else 12V you use when you want to operate and
then calculate what the charge needed for the operating session was, as
opposed to what you thought it might be (surprise differences are
interesting) will be and you'll be able to calculate what battery charge
you need. Then work out what battery/batteries will provide it.

You can expensive Li batteries but you need expensive chargers and you
will NOT be able to fly anywhere with them (legally anyway).

If you are trying to do this with a rucksack and lightweight then get a
smaller radio :-) If you have a vehicle, and no limits then get as large
a battery as you can recharge (jump leads between the vehicle and the
battery will recharge it cheaply and that is why I would not suggest
expensive Li batteries. If you want you can 'float the battery' between
the vehicle (or a generator) and the rig as well.

72

Dom
M1KTA

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Ignacy

Re: Good Battery for K3 Portable Ops

In reply to this post by Paul Grigorieff

batteryspace.com has a 20A LiFEPO3 battery for $120 and weighs 7lb, half of what lead acid does. Good for a couple of hrs at 100W level. This battery charges real fast.

Ignacy, NO9E

WB4SON

Re: Good Battery for K3 Portable Ops

I ran my club's FD GOTA station off battery/solar power this year. The
GOTA station was in heavy use for about half the 24 hour period, and
lighter use for the rest.

Over that contest and several others, I've developed the following
guidelines for my K3:

1) Casual operation is about 2 AH per hour (a few Qs an hour)
2) GOTA operation is about 3 AH per hour (a dozen Qs an hour)
3) Full run mode high Q rate (200 Qs an hour), takes 9.5 AH per hour

LiFePO4 batteries are great for this purpose and available in many sizes.
Higher voltage, more usable power, smaller size and weight are all
improvements over SLA batteries.

I have used a 10 AH LiFePO4 battery with my K3 for 4 hour periods MANY
times. We ran a K3 in full contest run mode for a solid hour off the same
battery.

Some brands to consider: K2 Energy, Tenergy, Bioenno.

They all sell "SLA Drop-in Replacement" batteries that have built-in
battery management electronics that protect from over-charge,
over-discharge, and keep the internal cells balanced. Expect the life to be
at least 5 times that of a SLA, and the weight to be 1/4th (if comparing
identical usable capacity -- you need a 20AH SLA to equal the usable
capacity of a 10AH LiFePO4). Only thing to watch for is to make sure the
battery management system is compatible with a 20 amp load.

73, Bob, WB4SON
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73, Bob, WB4SON