Battery Charging with DC Power Supply

[Bill - K6WLM]

<I am using an Alinco DM-330M power supply. Across the output of the <power supply I have a 26 AH battery. If the AC power quits I have <many hours to shut down the K3.
 
Charging a battery with a DC supply not meant for that purpose is a very BAD idea.
 
In the case of Astron supplies it can damage parts of the DC regulator.  If there is a "Crow Bar" circuit that operates with a battery connected to the power supply output it will ruin your day or even burn your house down!
 
Bill - K6WLM


     
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[Matt Zilmer]

I just have to chime in on this one.

I run my K3/100-based station on solar photovoltaic power, with a 100
AH SLA battery for storage.  Quick description of this installation is
that I use a charge controller to regulate battery charging.  It's a
Micro M+ c/c and can put out 4A for a 12VDC system.
http://edge.rit.edu/content/P07308/public/Custom%20Charge%20controller
The article is from October, 2001 QST.

As others have stated, you should not charge *any* battery directly
from an uncontrolled source like a power supply.  If you want to use
the battery as the main power source and recharge it periodically (or
whenever the sun shines), you have to regulate the charge rate and
voltage level presented to the battery.  The Micro M+ does a fine job
for smaller installations, and its max charge rate of 4A is adequate
for topping a battery in the 100AH class.  The Micro M+ uses pulse
width to control the charge rate, and this is suggested for FLA and
SLA battery types - others work with this method too (AGM, etc.).

You can use the Micro M+ or its equivalent for any type of source -
power supply, solar PV, bicycle generator, etc.  When the weather is
cloudy, I use a little Tektronics 3A AC/DC power supply and just run
it full bore into the c/c.  This works fine too.

<Details are below for those that are insomniacs>

Near the _big_ PV panels on the roof are the two Siemens SR50's, which
are rated 50W each, and they are in parallel for the 12VDC system. The
feed to the shack travels through a weatherproof enclosure that has a
10A fuse and GFP circuit breaker.  This might be overkill. Together
the two Siemens 50W panels are nameplate rated at around 6A. In
practice, maximum output is a little over 5A on a really good sun day.

The feed down to the shack is 8AWG THHN wire, about 30 feet of it, in
flexible NMT.  The 8AWG is to minimize the voltage drop to the charge
circuitry.

Both the battery and charge controller are here in the shack.

73,
matt zilmer W6NIA
K3 #24, K2 #2810


On Sun, 07 Jun 2009 21:17:17 -0700 (PDT), you wrote:

><I am using an Alinco DM-330M power supply. Across the output of the <power supply I have a 26 AH battery. If the AC power quits I have <many hours to shut down the K3.
> 
>Charging a battery with a DC supply not meant for that purpose is a very BAD idea.
> 
>In the case of Astron supplies it can damage parts of the DC regulator.  If there is a "Crow Bar" circuit that operates with a battery connected to the power supply output it will ruin your day or even burn your house down!
> 
>Bill - K6WLM
>
>
>      
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[dave-281]

I'm not quite sure what is meant by the term 'uncontrolled source'. A
regulated power supply makes a fine battery charger. Review the
charging recommendations at the various battery manufacturer sites
such as here:

<http://www.power-sonic.com/index.php?doc_id=116>

or here:

<http://www.powerstream.com/SLA.htm>

and you will see that constant voltage charging is one of several
recommended charging methods.

The charge voltage needs to be carefully regulated, which Aston and
other power supplies should do, and it is certainly a very good idea
to put a fuse in line with each battery to protect against the unknown.

But there is absolutely nothing wrong with constant voltage float
charging. At the phone co. we kept batteries on float charge for 20 to
25 years and they were instantly ready, indeed constantly on line, and
fully charged.

Keep the charge voltage set correctly, use proper safety precautions,
follow the battery manufacturer's recommendations, and you should be fine.

The recommended charge voltage varies by the type of battery. Flooded
batteries require a somewhat lower voltage than do SLA or AGM types.
For flooded cells the usual recommendation is about 13.5 to 13.6, but
some manufacturers are lower than this, and for AGM it is usually a
bit higher at 13.6 to 13.8. Check with the battery manufacturer to be
sure.

What you are trying to do is keep the battery fully charged but yet
not burn off the water nor damage the plates.


73 de dave
ab9ca/4





Matt Zilmer wrote:

> I just have to chime in on this one.
>
> I run my K3/100-based station on solar photovoltaic power, with a 100
> AH SLA battery for storage.  Quick description of this installation is
> that I use a charge controller to regulate battery charging.  It's a
> Micro M+ c/c and can put out 4A for a 12VDC system.
> http://edge.rit.edu/content/P07308/public/Custom%20Charge%20controller
> The article is from October, 2001 QST.
>
> As others have stated, you should not charge *any* battery directly
> from an uncontrolled source like a power supply.  If you want to use
> the battery as the main power source and recharge it periodically (or
> whenever the sun shines), you have to regulate the charge rate and
> voltage level presented to the battery.  The Micro M+ does a fine job
> for smaller installations, and its max charge rate of 4A is adequate
> for topping a battery in the 100AH class.  The Micro M+ uses pulse
> width to control the charge rate, and this is suggested for FLA and
> SLA battery types - others work with this method too (AGM, etc.).
>
> You can use the Micro M+ or its equivalent for any type of source -
> power supply, solar PV, bicycle generator, etc.  When the weather is
> cloudy, I use a little Tektronics 3A AC/DC power supply and just run
> it full bore into the c/c.  This works fine too.
>
> <Details are below for those that are insomniacs>
>
> Near the _big_ PV panels on the roof are the two Siemens SR50's, which
> are rated 50W each, and they are in parallel for the 12VDC system. The
> feed to the shack travels through a weatherproof enclosure that has a
> 10A fuse and GFP circuit breaker.  This might be overkill. Together
> the two Siemens 50W panels are nameplate rated at around 6A. In
> practice, maximum output is a little over 5A on a really good sun day.
>
> The feed down to the shack is 8AWG THHN wire, about 30 feet of it, in
> flexible NMT.  The 8AWG is to minimize the voltage drop to the charge
> circuitry.
>
> Both the battery and charge controller are here in the shack.
>
> 73,
> matt zilmer W6NIA
> K3 #24, K2 #2810
>
>
> On Sun, 07 Jun 2009 21:17:17 -0700 (PDT), you wrote:
>
>> <I am using an Alinco DM-330M power supply. Across the output of the <power supply I have a 26 AH battery. If the AC power quits I have <many hours to shut down the K3.
>>  
>> Charging a battery with a DC supply not meant for that purpose is a very BAD idea.
>>  
>> In the case of Astron supplies it can damage parts of the DC regulator.  If there is a "Crow Bar" circuit that operates with a battery connected to the power supply output it will ruin your day or even burn your house down!
>>  
>> Bill - K6WLM
>>
>>
>>      
>> ______________________________________________________________
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>

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[AC7AC]

CONTENTS DELETED

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[n7ws]

Since Astron has been mentioned in this thread, I'll use that as an example.

The SCR that is part of the crowbar is connected directly across the output terminals of the supply.  When used normally, the firing of the SCR shorts the output and the supply goes into current limit, if still functional, or hopefully blows the primary fuse if not.

With a battery across the output, if the SCR fires, something is going to fuse.  It will be either a user-installed external fuse or something else.  It would probably not be a good idea to rely on the something else.

Wes  N7WS

--- On Mon, 6/8/09, Ron D'Eau Claire <[hidden email]> wrote:

From: Ron D'Eau Claire <[hidden email]>
Subject: Re: [Elecraft] Battery Charging with DC Power Supply
To: "'Bill Miner'" <[hidden email]>, [hidden email]
Date: Monday, June 8, 2009, 8:15 AM

Bill - K6WLM wrote:

In the case of Astron supplies it can damage parts of the DC regulator.  If
there is a "Crow Bar" circuit that operates with a battery connected to the
power supply output it will ruin your day or even burn your house down.

---------------------------

How can that produce damage or a fire hazard?

A "crowbar" shuts off the power supply so it produces no output if too much
current is drawn from it specifically to protect the regulator.

That might happen if the power supply is turned on when the battery is
discharged enough it demands more than the crowbar current limit, but the
crowbar is designed to avoid any dangerous or damaging operation.

Typically, the supply remains *off* until the power switch is operated
manually, off then on, so it won't keep trying to feed current into a short
circuit somewhere. I know that's how the Astrons I've used work.

So, as far as I can see, the worse that could happen is you end up with a
dead battery if you have a discharge path with the supply off.


Ron AC7AC

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[n7ws]

Finally, a voice of reason.

--- On Sun, 6/7/09, dave <[hidden email]> wrote:

From: dave <[hidden email]>
Subject: Re: [Elecraft] Battery Charging with DC Power Supply
To: [hidden email]
Cc: [hidden email], "Bill Miner" <[hidden email]>
Date: Sunday, June 7, 2009, 11:36 PM


I'm not quite sure what is meant by the term 'uncontrolled source'. A
regulated power supply makes a fine battery charger. Review the
charging recommendations at the various battery manufacturer sites
such as here:

<http://www.power-sonic.com/index.php?doc_id=116>

or here:

<http://www.powerstream.com/SLA.htm>

and you will see that constant voltage charging is one of several
recommended charging methods.

The charge voltage needs to be carefully regulated, which Aston and
other power supplies should do, and it is certainly a very good idea
to put a fuse in line with each battery to protect against the unknown.

But there is absolutely nothing wrong with constant voltage float
charging. At the phone co. we kept batteries on float charge for 20 to
25 years and they were instantly ready, indeed constantly on line, and
fully charged.

Keep the charge voltage set correctly, use proper safety precautions,
follow the battery manufacturer's recommendations, and you should be fine.

The recommended charge voltage varies by the type of battery. Flooded
batteries require a somewhat lower voltage than do SLA or AGM types.
For flooded cells the usual recommendation is about 13.5 to 13.6, but
some manufacturers are lower than this, and for AGM it is usually a
bit higher at 13.6 to 13.8. Check with the battery manufacturer to be
sure.

What you are trying to do is keep the battery fully charged but yet
not burn off the water nor damage the plates.


73 de dave
ab9ca/4





     
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[WILLIS COOKE]

Be careful.  There is a voltage that is safe for trickle charging a battery, but it is not the same voltage that is optimum for powering a transceiver.  Most if not all transceivers are built for optimum operation at about 13.8 volts which is also the optimum charging voltage for a short term charge of your car battery.  They also work well at 12 volts or a little less so that you can use a car battery when you are not running the engine.  Most of us keep our power supply adjusted to about 13.8V which is a good voltage for battery charging, but not so good for continuous charge.  You will ruin a battery if you keep the voltage that high for long periods.  I don't have the battery specs on hand at the moment but something like 12.3 to 12.5V would be a good continuous voltage.  Also, you have the challenge of connecting at least two large wires to the output terminals of the charger which is difficult on some chargers.  The Astron supply that I have has
 some nice large bolts for connectors, but others have binding posts that are more difficult.

A better solution is to have a separate power supply output for the battery charger and a variable charge circuit to restore the charge after use then reduce the charging voltage for maintenance.  Such a supply is made by JetStream, Model JTPS35BCM and probably others.  I am in the process of installing one in my shack at the moment.  It is reasonably priced and seems a good idea,  I will let you know later how well it works.

Willis 'Cookie' Cooke
K5EWJ


--- On Mon, 6/8/09, Wes Stewart <[hidden email]> wrote:

> From: Wes Stewart <[hidden email]>
> Subject: Re: [Elecraft] Battery Charging with DC Power Supply
> To: [hidden email]
> Date: Monday, June 8, 2009, 7:40 AM
> Finally, a voice of reason.
>

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[w4nhj]

I believe I read somwhere that you can do a mod to Astron power supplies to
make the float chargable.  They sell supplies that say they are for battery
back-up, I suspect they are already modified for float charge.

Frank - W4NHJ

----- Original Message -----
From: "Ron D'Eau Claire" <[hidden email]>
To: "'Bill Miner'" <[hidden email]>; <[hidden email]>
Sent: Monday, June 08, 2009 10:15 AM
Subject: Re: [Elecraft] Battery Charging with DC Power Supply

> Bill - K6WLM wrote:
>
> In the case of Astron supplies it can damage parts of the DC regulator.
> If
> there is a "Crow Bar" circuit that operates with a battery connected to
> the
> power supply output it will ruin your day or even burn your house down.
>
> ---------------------------
>
> How can that produce damage or a fire hazard?
>
> A "crowbar" shuts off the power supply so it produces no output if too
> much
> current is drawn from it specifically to protect the regulator.
>
> That might happen if the power supply is turned on when the battery is
> discharged enough it demands more than the crowbar current limit, but the
> crowbar is designed to avoid any dangerous or damaging operation.
>
> Typically, the supply remains *off* until the power switch is operated
> manually, off then on, so it won't keep trying to feed current into a
> short
> circuit somewhere. I know that's how the Astrons I've used work.
>
> So, as far as I can see, the worse that could happen is you end up with a
> dead battery if you have a discharge path with the supply off.
>
>
> Ron AC7AC
>
> ______________________________________________________________
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[AC7AC]

CONTENTS DELETED

The author has deleted this message.

[Doug Faunt N6TQS [phone]]

There was an article in QST a good while back about this.  Theer were
two things that needed to be done, one of which was a fuse between the
battery and the power supply so if the crowbar triggered, the PS
wouldn't burn up, and the other was a resistor added so the 723
regulator would be protected against the reverse voltage condition
when the AC power side is off.  I can't spot the article in the ARRL
QST index, but may be able to locate information later.

And the Astron supplies with the battery backup option will cheerfully
fry a battery in a pretty short time.

73, doug

   From: "Frank Ross W4NHJ" <[hidden email]>
   Date: Mon, 8 Jun 2009 11:21:03 -0400

   I believe I read somwhere that you can do a mod to Astron power supplies to
   make the float chargable.  They sell supplies that say they are for battery
   back-up, I suspect they are already modified for float charge.

   Frank - W4NHJ

   ----- Original Message -----
   From: "Ron D'Eau Claire" <[hidden email]>
   To: "'Bill Miner'" <[hidden email]>; <[hidden email]>
   Sent: Monday, June 08, 2009 10:15 AM
   Subject: Re: [Elecraft] Battery Charging with DC Power Supply


   > Bill - K6WLM wrote:
   >
   > In the case of Astron supplies it can damage parts of the DC regulator.
   > If
   > there is a "Crow Bar" circuit that operates with a battery connected to
   > the
   > power supply output it will ruin your day or even burn your house down.
   >
   > ---------------------------
   >
   > How can that produce damage or a fire hazard?
   >
   > A "crowbar" shuts off the power supply so it produces no output if too
   > much
   > current is drawn from it specifically to protect the regulator.
   >
   > That might happen if the power supply is turned on when the battery is
   > discharged enough it demands more than the crowbar current limit, but the
   > crowbar is designed to avoid any dangerous or damaging operation.
   >
   > Typically, the supply remains *off* until the power switch is operated
   > manually, off then on, so it won't keep trying to feed current into a
   > short
   > circuit somewhere. I know that's how the Astrons I've used work.
   >
   > So, as far as I can see, the worse that could happen is you end up with a
   > dead battery if you have a discharge path with the supply off.
   >
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[David Pratt]

In a recent message, Doug Faunt N6TQS [phone] <[hidden email]>
wrote ...
>
>There was an article in QST a good while back about this.  Theer were
>two things that needed to be done, one of which was a fuse between the
>battery and the power supply so if the crowbar triggered, the PS
>wouldn't burn up, and the other was a resistor added so the 723
>regulator would be protected against the reverse voltage condition
>when the AC power side is off.

The KBT2 option for the K2 is designed for the SLA battery to be charged
continuously while the K2 is run from an external 13.8V power supply. A
Shottky diode in parallel with a resistor is in series with the battery.
http://www.elecraft.com/manual/KBT2_manual_.pdf

My K2 has been run for many years under this condition and there is
plenty life still in the battery.  If the power is removed, the K2 keeps
on running.

73
--
David G4DMP
Leeds, England, UK
------


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[dave-281]

A voltage as low as 12.anything will result in a sulfated battery. The
lowest float voltage I am aware of is 13.02 (2.17 VPC) on the
Rolls/Surrette batteries. All other manufacturers (that I am aware of)
recommend something closer to 13.5 or so. Don't listen to me or anyone
else on here - check the manufacturer's recommendations!!

Yes, if you run your power supply at 13.5 or 13.4 to do a float charge
a battery you will likely lose a little maximum power out. But there
should be no harm to the rig. Instead of getting 100w out you may get
only 90 or so. But this is only about 0.5 dB and undetectable on the
RX end. A small price to pay for having continuous backup power, or so
it seems to me - YMMV. I think most rigs have an adjustment for the
power out - if you can find it!

Remember what you are trying to do is keep the battery fully charged
without cooking the water out nor damaging the plates. If you watch
the water consumption you can tell if the float voltage is too high.
If you have to add water more than about once a year the voltage is
too high. I try to keep the float voltage about 13.5 or 13.6 and add
water only every couple of years to the ones here.

A voltage too low is much harder to detect. The only sign is loss of
capacity in the battery due to sulfation. The only valid test I know
of is to do a load test. So it is better to err a bit on the high side
and watch the water consumption then to sulfate the battery.

Re: the Jetstream switching supplies. A friend brought one by and we
took a look at it with the spectrum analyzer. That one was a horrible
noise producer. Lots of spurs well up into the VHF frequencies.


73 de dave
ab9ca/4




WILLIS COOKE wrote:

> Be careful.  There is a voltage that is safe for trickle charging a
> battery, but it is not the same voltage that is optimum for
> powering a transceiver.  Most if not all transceivers are built for
> optimum operation at about 13.8 volts which is also the optimum
> charging voltage for a short term charge of your car battery.  They
> also work well at 12 volts or a little less so that you can use a
> car battery when you are not running the engine.  Most of us keep
> our power supply adjusted to about 13.8V which is a good voltage
> for battery charging, but not so good for continuous charge.  You
> will ruin a battery if you keep the voltage that high for long
> periods.  I don't have the battery specs on hand at the moment but
> something like 12.3 to 12.5V would be a good continuous voltage.
> Also, you have the challenge of connecting at least two large wires
> to the output terminals of the charger which is difficult on some
> chargers.  The Astron supply that I have has some nice large bolts
> for connectors, but others have binding posts that are more
> difficult.
>
> A better solution is to have a separate power supply output for the
> battery charger and a variable charge circuit to restore the charge
> after use then reduce the charging voltage for maintenance.  Such a
> supply is made by JetStream, Model JTPS35BCM and probably others.
> I am in the process of installing one in my shack at the moment.
> It is reasonably priced and seems a good idea,  I will let you know
> later how well it works.
>
> Willis 'Cookie' Cooke K5EWJ
>
>
> --- On Mon, 6/8/09, Wes Stewart <[hidden email]> wrote:
>
>> From: Wes Stewart <[hidden email]> Subject: Re: [Elecraft]
>> Battery Charging with DC Power Supply To:
>> [hidden email] Date: Monday, June 8, 2009, 7:40 AM
>> Finally, a voice of reason.
>>
>
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[HowardZ]

http://www.eham.net/reviews/detail/4103

http://www.iotaengineering.com/iq.htm

[n7ws]

If still functional, the power supply regulator isn't "turned off", it still tries to supply some current* into the (nearly) short circuit SCR.  At the same time the battery supplies current limited only by its internal impedance and the resistance of the interconnect.

* If I'm not mistaken (always a good possibility) the Astrons use foldback current limiting to limit the dissipation of the pass transistors.


--- On Mon, 6/8/09, Ron D'Eau Claire <[hidden email]> wrote:

From: Ron D'Eau Claire <[hidden email]>
Subject: RE: [Elecraft] Battery Charging with DC Power Supply
To: "'Wes Stewart'" <[hidden email]>, "'Bill Miner'" <[hidden email]>, [hidden email]
Date: Monday, June 8, 2009, 9:23 AM




 
 






Tnx Wes!  

  

So the battery voltage across  the power supply terminals
keeps the SCR turned on, even though the supply voltage is turned off by the
crowbar.  

That would surely lead to a dead SCR without a suitable fuse in
the battery circuit.  

  

Ron AC7AC  

  

  

  


 
 
  Since Astron has been mentioned in this thread, I'll use
  that as an example.

 

  The SCR that is part of the crowbar is connected directly across the output
  terminals of the supply.  When used normally, the firing of the SCR
  shorts the output and the supply goes into current limit, if still
  functional, or hopefully blows the primary fuse if not.

 

  With a battery across the output, if the SCR fires, something is going to
  fuse.  It will be either a user-installed external fuse or something
  else.  It would probably not be a good idea to rely on the something
  else.

 

  Wes  N7WS

 

 

   
 
 


  



 




     
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[HowardZ]

The power supply that is built to also be a battery charger
http://www.iotaengineering.com/dls45.htm


The reviews:
http://www.eham.net/reviews/detail/4103

Add an EXTERNAL IQ4 for better battery charging
http://www.iotaengineering.com/iq.htm

Do not buy the model with INTERNAL IQ4.

Howard

[n7ws]

I have a travel trailer that had a switch-mode charger that was so noisy that it interfered with (analog) TV reception in my house, when the trailer was next to the house on shore power.  Needless to say, radio operation was problematic.

So I built an analog smart charger using an Astron RS-35M for the case, raw DC and the pass transistors and an A&A Engineering board using the uC3906 IC.  I used this for a time externally, since it wouldn't fit and wasn't rugged enough to occupy the space in the trailer.  I now have this in the shack keeping a 95AH AGM battery charged for emergency use.

I replaced the trailer charger with the Iota DLS-45 (40 years ago I worked with some of the founders of this company).  It isn't totally electrically quiet, but for a switcher it isn't too bad.  Not good enough to go in my shack though.

Wes  N7WS



--- On Mon, 6/8/09, HowardZ <[hidden email]> wrote:

From: HowardZ <[hidden email]>
Subject: Re: [Elecraft] Battery Charging with DC Power Supply
To: [hidden email]
Date: Monday, June 8, 2009, 12:52 PM


http://www.eham.net/reviews/detail/4103

http://www.iotaengineering.com/iq.htm





     
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[list1]

Hi All,
Just a note on the Iota DLS-30/IQ4 that I have.  I originally purchased it
because I thought that I could also use it as a power supply as it is
advertised.  As it turns out I can not use my Elecraft K2 while it is
plugged in charging a battery.  The RFI is very great on 80 meters up to I
think 30 meters.  I don't believe that these are made for receivers as I do
not see any RFI suppression inside (I could be wrong).  I had emailed the
distributer to get a schmatic so I could try to add some RFI protection to
it inside the case but got nowhere.  So I use it to charge my 2 T-105s at
night when I'm not on the radio.

Steve, W2MY


-----Original Message-----
From: [hidden email]
[mailto:[hidden email]]On Behalf Of HowardZ

http://www.eham.net/reviews/detail/4103

http://www.iotaengineering.com/iq.htm

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[AC7AC]

CONTENTS DELETED

The author has deleted this message.

[list1]

Hi All,
I see that this was asked once before on the reflector but got no replies.

How well does the KAT3 work outside of the ham bands?  Are the settings
still stored for out-of-band frequencies like those which are used for MARS
operation?  My other choices are the LDG AT 200 Pro and one of the MFJ
units.

Steve, W2MY, AAR6CX

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[Matt Zilmer]

Sorry, guess that term wasn't real clear.

A power supply doesn't control the charge rate, it controls the output
voltage.  Most bulk storage batteries don't want to charge at high
rates, say over 0.5C, although you can probably get away with it for a
time.  Controlling the charge rate generally improves battery life,
although other things like equalization can help with this too (FLA's
only!).

For the SLA I have here, the recommended maximum continuous CV charge
rate is 0.3C.  In a way they're fairly picky when it comes to charging
rates.

Charging in a CV regime is fine as long as the rate is limited to
whatever is best for the battery.  But most power supplies that can
handle a 100W rig like the K3 can may output more than this
recommended charge rate, and unless you manually set the current limit
to the max rate, they're uncontrolled in this respect.

As with all things, YMMV applies.  If you have a mega-battery like
some 1200AH deep cycle home power type, then the max rate will be
different.  It's a guess, but I think most hams wouldn't be using that
type of Rolls or Surette battery for their stations.  I'd sure like to
have a set for the main PV system here though.

The home power batteries we use for the main PV system are 210 AH 6V
golf cart batteries, a series string of 8 of them.  The
charger/inverter is set up to charge them at a rate only as high as
0.2C in normal circumstances (this is Exide's recommendation for max
life).  However, if we're off grid for awhile, I set it up to run
0.35C for about 2 hours  to bulk them up.  In this system , it is
normal to pulse charge them.  Some people call this a float or trickle
charge.  Xantrex just calls it "normal" for some reason.

73,
matt W6NIA








On Mon, 08 Jun 2009 00:36:13 -0500, you wrote:

>
>I'm not quite sure what is meant by the term 'uncontrolled source'. A
>regulated power supply makes a fine battery charger. Review the
>charging recommendations at the various battery manufacturer sites
>such as here:
>
><http://www.power-sonic.com/index.php?doc_id=116>
>
>or here:
>
><http://www.powerstream.com/SLA.htm>
>
>and you will see that constant voltage charging is one of several
>recommended charging methods.
>
>The charge voltage needs to be carefully regulated, which Aston and
>other power supplies should do, and it is certainly a very good idea
>to put a fuse in line with each battery to protect against the unknown.
>
>But there is absolutely nothing wrong with constant voltage float
>charging. At the phone co. we kept batteries on float charge for 20 to
>25 years and they were instantly ready, indeed constantly on line, and
>fully charged.
>
>Keep the charge voltage set correctly, use proper safety precautions,
>follow the battery manufacturer's recommendations, and you should be fine.
>
>The recommended charge voltage varies by the type of battery. Flooded
>batteries require a somewhat lower voltage than do SLA or AGM types.
>For flooded cells the usual recommendation is about 13.5 to 13.6, but
>some manufacturers are lower than this, and for AGM it is usually a
>bit higher at 13.6 to 13.8. Check with the battery manufacturer to be
>sure.
>
>What you are trying to do is keep the battery fully charged but yet
>not burn off the water nor damage the plates.
>
>
>73 de dave
>ab9ca/4
>
>
>
>
>
>Matt Zilmer wrote:
>> I just have to chime in on this one.
>>
>> I run my K3/100-based station on solar photovoltaic power, with a 100
>> AH SLA battery for storage.  Quick description of this installation is
>> that I use a charge controller to regulate battery charging.  It's a
>> Micro M+ c/c and can put out 4A for a 12VDC system.
>> http://edge.rit.edu/content/P07308/public/Custom%20Charge%20controller
>> The article is from October, 2001 QST.
>>
>> As others have stated, you should not charge *any* battery directly
>> from an uncontrolled source like a power supply.  If you want to use
>> the battery as the main power source and recharge it periodically (or
>> whenever the sun shines), you have to regulate the charge rate and
>> voltage level presented to the battery.  The Micro M+ does a fine job
>> for smaller installations, and its max charge rate of 4A is adequate
>> for topping a battery in the 100AH class.  The Micro M+ uses pulse
>> width to control the charge rate, and this is suggested for FLA and
>> SLA battery types - others work with this method too (AGM, etc.).
>>
>> You can use the Micro M+ or its equivalent for any type of source -
>> power supply, solar PV, bicycle generator, etc.  When the weather is
>> cloudy, I use a little Tektronics 3A AC/DC power supply and just run
>> it full bore into the c/c.  This works fine too.
>>
>> <Details are below for those that are insomniacs>
>>
>> Near the _big_ PV panels on the roof are the two Siemens SR50's, which
>> are rated 50W each, and they are in parallel for the 12VDC system. The
>> feed to the shack travels through a weatherproof enclosure that has a
>> 10A fuse and GFP circuit breaker.  This might be overkill. Together
>> the two Siemens 50W panels are nameplate rated at around 6A. In
>> practice, maximum output is a little over 5A on a really good sun day.
>>
>> The feed down to the shack is 8AWG THHN wire, about 30 feet of it, in
>> flexible NMT.  The 8AWG is to minimize the voltage drop to the charge
>> circuitry.
>>
>> Both the battery and charge controller are here in the shack.
>>
>> 73,
>> matt zilmer W6NIA
>> K3 #24, K2 #2810
>>
>>
>> On Sun, 07 Jun 2009 21:17:17 -0700 (PDT), you wrote:
>>
>>> <I am using an Alinco DM-330M power supply. Across the output of the <power supply I have a 26 AH battery. If the AC power quits I have <many hours to shut down the K3.
>>>  
>>> Charging a battery with a DC supply not meant for that purpose is a very BAD idea.
>>>  
>>> In the case of Astron supplies it can damage parts of the DC regulator.  If there is a "Crow Bar" circuit that operates with a battery connected to the power supply output it will ruin your day or even burn your house down!
>>>  
>>> Bill - K6WLM
>>>
>>>
>>>      
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>>

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