14 volt batteries?

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14 volt batteries?

Robert Sands
Why are we stuck with 12 volt batteries of all types when the rigs are
optimal at 13.6 or 14 volts? Anyone know of a 14 volt battery mfg? My
search yields zero.
Bob K7VO
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Robert Sands
K7VO
Olympia, WA
Tox
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Re: 14 volt batteries?

Tox
Many "12v" batteries are actually 13.2-13.8 when fully charged

On Sunday, August 20, 2017, Robert Sands <[hidden email]> wrote:

> Why are we stuck with 12 volt batteries of all types when the rigs are
> optimal at 13.6 or 14 volts? Anyone know of a 14 volt battery mfg? My
> search yields zero.
> Bob K7VO
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--
Scott Small
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Re: 14 volt batteries?

Chris Parfitt
I agree, LiFePO4 4S batteries should be charged to around 13.2, with 12.6 volts being nominal. LiPo 4S batteries have a nominal voltage of 14.8, but are fully charged at 16.8—too high for most transceivers. I have seen examples of people using various methods to decrease the voltage under 16.

Although not exactly cheap, the LiFePO4 4S batteries work well with my KX3. I also have some smaller and more portable LiPo 3S batteries, which I use from 12.6 down to around 10.8 volts.

Chris, AC4MP


> On Aug 20, 2017, at 8:21 PM, Tox <[hidden email]> wrote:
>
> Many "12v" batteries are actually 13.2-13.8 when fully charged
>
> On Sunday, August 20, 2017, Robert Sands <[hidden email]> wrote:
>
>> Why are we stuck with 12 volt batteries of all types when the rigs are
>> optimal at 13.6 or 14 volts? Anyone know of a 14 volt battery mfg? My
>> search yields zero.
>> Bob K7VO
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
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>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email] <javascript:;>
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>
>
> --
> Scott Small
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Re: 14 volt batteries?

Rick WA6NHC-2
In reply to this post by Robert Sands
Look at LiFePO batteries.  The charging needs are specific (meaning
you'll have to make an investment), but they'll maintain voltage (13v+)
until they can't, a very sharp knee.

Rick nhc


On 8/20/2017 5:19 PM, Robert Sands wrote:
> Why are we stuck with 12 volt batteries of all types when the rigs are
> optimal at 13.6 or 14 volts? Anyone know of a 14 volt battery mfg? My
> search yields zero.
> Bob K7VO

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Re: 14 volt batteries?

Don Wilhelm
In reply to this post by Robert Sands
Bob,

For a long time, rigs were designed for the nominal voltage obtained
from a fully charged Lead Acid battery which is 13.6 to 13.8 volts when
fully charged.  Think automotive batteries and mobile operation - that
has been the design point for transceivers in the 100 watt and under class.

More recent battery technology have produced a number of batteries with
different voltages, but most ham gear has stayed with the voltage
commonly available in a vehicular mobile environment.  That is just "the
fact of the matter".

73,
Don W3FPR

On 8/20/2017 8:19 PM, Robert Sands wrote:
> Why are we stuck with 12 volt batteries of all types when the rigs are
> optimal at 13.6 or 14 volts? Anyone know of a 14 volt battery mfg? My
> search yields zero.
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Re: 14 volt batteries?

Jim Brown-10
In reply to this post by Rick WA6NHC-2
Right on!  For about a year, I've been running the radios in my shack
from a 10Ah LiFePO4 battery from Bioenne Power.  I never see the voltage
drop below 13V on the K3 voltmeter.

73, Jim K9YC

On 8/20/2017 6:08 PM, Rick WA6NHC wrote:
> Look at LiFePO batteries.  The charging needs are specific (meaning
> you'll have to make an investment), but they'll maintain voltage
> (13v+) until they can't, a very sharp knee.


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Re: 14 volt batteries?

Jim Brown-10
In reply to this post by Tox
On 8/20/2017 5:21 PM, Tox wrote:
> Many "12v" batteries are actually 13.2-13.8 when fully charged

Not after you've disconnected the charger. And the voltage drops VERY
quickly as they discharge. With 90% charge remaining, they're close to 12V!

73, Jim K9YC

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Re: 14 volt batteries?

Jim Brown-10
In reply to this post by Chris Parfitt
On 8/20/2017 5:46 PM, Chris Parfitt wrote:
> I agree, LiFePO4 4S batteries should be charged to around 13.2, with 12.6 volts being nominal.

14.2V for full charge is more like it. And you're right that they should
NOT be charged much above that, which is why chargers specifically
designed for that battery chemistry must be used. And as Don notes, the
design voltage for most ham gear is 13.8 VDC, which is the voltage to
which an alternator regulates. When the alternator stops, the voltage
drops to about 12.6 at full charge.

73, Jim K9YC

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Re: 14 volt batteries?

Ignacy
Most rigs are designed for a range (13.8V +- 15%). IMD3 are better at higher voltage, but excellent IMD3 with predistortion can make this point moot.

Many computer chips operate at 1.5V, and conversion from 12V is normal. Expert amp 1.3k operates at full power from 90 to 270V.  Apache 8000 has 12V/50V conversion inside.  

With newer generation and predistortion + more intelligent design, radios may limit themselves to max power at given voltage, all with excellent IMD and high efficiency.  Say 80W at 10V to 150W at 16V.

Ignacy, NO9E  
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Re: 14 volt batteries?

Nr4c
In reply to this post by Robert Sands
4S Lipos.

Lipo cells are 3.7 V nominal. So 4 in series would be 14.8 Volts.

Sent from my iPhone
...nr4c. bill


> On Aug 20, 2017, at 8:19 PM, Robert Sands <[hidden email]> wrote:
>
> Why are we stuck with 12 volt batteries of all types when the rigs are
> optimal at 13.6 or 14 volts? Anyone know of a 14 volt battery mfg? My
> search yields zero.
> Bob K7VO
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
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Re: 14 volt batteries?

Phil Kane-2
In reply to this post by Don Wilhelm
On 8/20/2017 7:10 PM, Don Wilhelm wrote:

> More recent battery technology have produced a number of batteries with
> different voltages, but most ham gear has stayed with the voltage
> commonly available in a vehicular mobile environment.  That is just "the
> fact of the matter".

Commercial "fixed station" equipment has largely migrated to 48V, the
historical "Bell System" standard.

73 de K2ASP - Phil Kane
Elecraft K2/100   s/n 5402

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon
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Re: 14 volt batteries?

Jim Brown-10
In reply to this post by Jim Brown-10
Hi Charlie,

Since your question is likely of interest to others, I'm responding to
the reflector.  My system is float charged using a Genasun MPPT solar
charge regulator designed for LiFePO4 batteries. My solar array is quite
small, composed of 4 panels gifted by a friend who recovered them from a
dumpster after they had been replaced in instrumentation setups. Because
I'm in a redwood forest, they get far less illumination than they would
in a more typical installation. During the summer months, they're
producing charging current from about 9:30 am to about 4:30 pm. From
early fall to late spring, they're barely illuminated at all.

When the sun is not enough, I disconnect the panels and use an old
computer laptop power supply to feed the charge regulator.  That's
enough to run a single K3 for contesting at full power, but not for two
K3s in heavy SO2R. It is enough to run SO2R at the much lower power
levels needed to drive my power amps.

I've done two things to address that. First, the LiFePO4 battery only
runs the radios. Other 12V gear in the shack runs from a big Costco deep
discharge battery, floated in the same manner from another old laptop
power supply. Second, for 100W contests, I reduce K3 output to what it
takes to get 100W from my power amps, which varies from 5-8W, depending
on which amp and which band.

You asked about a 10Ah battery. W6JTI used my KX3/KXPA100 for two
ridgetop expeditions (3 miles up a trail that climbs 2,000 ft) to
activate the rare CM79 grid on 6M. He was joined on one trip by K6EU,
and on a second by N6ZFO. The first trip was for two days, and they
carried three 20Ah batteries. On the second trip for only one day, they
carried two. On both trips, they got through most of the day with one of
those batteries. The first time around, they were not familiar with the
KX3 power hookup, and by accident ran the KX3 on the internal NiMH AA
pack. That also got through much of that first day. it was a CW-only
operation. To gauge operating time, they were set up and on the air by
about 8 am and shut down between 6 and 7 pm (on the second trip, in time
to make it down the trail before dark).

So -- I'd say a 10Ah pack would be good for nearly continuous CW with a
barefoot KX3 all day. And, of course, there's the internal pack, which
for my batteries, is about 2.7Ah.

73, Jim K9YC

On 8/21/2017 4:32 AM, Charlie T, K3ICH wrote:

> Interesting comment Jim.
>
> I would have suspected that a 10 Ah battery might not be big enough.
>
> Assuming you have the 100 W K3, can you run full power using the LiFePO4
> battery?
> How about operating time?  Again, assuming casual not full contest mode.
> Also, do you leave the charger connected at all times? I'm guessing it is
> designed to operate like this.
>
> Currently, I have an old 2' X 4' solar panel charging a regular 24 size car
> battery with a diode isolated 3 Amp power supply in case the sun doesn't
> cooperate, all feeding a home brew switching type charger.
> It DOES make some beeps and squeals on the six meter band, but just a couple
> obvious spikes in the panadapter that I've learned to live with.
>
> Ultimately, if I converted to the newer battery, I'd still want the ability
> to use the solar panel to charge. I'm thinking that would take quite a bit
> of extra circuitry to accomplish.
>
> I typically get around ten years of life to a car battery in this situation.
> I'm hoping the LiFePO4 battery would have better lifetime considering the
> cost.
> Of course, when I started this set-up years ago,  you could buy a Wal-Mart
> battery for $29.95.  They're not that far from a LiFePOP4 battery pricing
> now days, especially if I could get away with a considerably lower Ah
> rating.
>
> I'm hoping this goes to you directly since I don't want to prolong an OT
> thread.
>
> 73, Charlie k3ICH
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Jim Brown
> Sent: Monday, August 21, 2017 12:17 AM
> To: [hidden email]
> Subject: Re: [Elecraft] 14 volt batteries?
>
> Right on!  For about a year, I've been running the radios in my shack from a
> 10Ah LiFePO4 battery from Bioenne Power.  I never see the voltage drop below
> 13V on the K3 voltmeter.
>
> 73, Jim K9YC
>
>
>

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