I know this question has probably been beaten to death, nevertheless I hope
you will still indulge me.

During a power outage, which occurs frequently in Florida, I would like to
use a battery to power some communication gear. Although the battery is 12v
and not 13.8v, I think that the gear will still work OK (hopefully).

Question 1. I believe that car batteries have a low internal resistance
because their primary function is to provide a lot of current for a short
time. There are other 12v large battery types that will last as long as a
typical car battery. They are designed not to provide peak current, but to
supply steady state current for a long time.
For the life of me, I can't remember the name of those type batteries so I
can't do a google to find a supplier. I hope this is making some sense.

Question 2. Where can I find articles & schematics for a solar cell to
provide a trickle charge for the aforementioned battery?

Thank you very much.

Cordially,
west

For solar cell recharging systems check out boating suppliers BoatUS or West
Marine. They are commonly used to keep boat batteries topped up. Since main
cost is the cell there is little reason to try build your own circuit

Car Batteries should work ok for what you want to do.

Dan

--
Dan Hollands
1120 S Creek Dr
Webster NY 14580
585-872-2606

www.QuickScoreRace.com
"west" wrote in message
...
I know this question has probably been beaten to death, nevertheless I hope
you will still indulge me.

During a power outage, which occurs frequently in Florida, I would like to
use a battery to power some communication gear. Although the battery is
12v
and not 13.8v, I think that the gear will still work OK (hopefully).

Question 1. I believe that car batteries have a low internal resistance
because their primary function is to provide a lot of current for a short
time. There are other 12v large battery types that will last as long as a
typical car battery. They are designed not to provide peak current, but to
supply steady state current for a long time.
For the life of me, I can't remember the name of those type batteries so I
can't do a google to find a supplier. I hope this is making some sense.

Question 2. Where can I find articles & schematics for a solar cell to
provide a trickle charge for the aforementioned battery?

Thank you very much.

Cordially,
west

"west" wrote in message
...
|I know this question has probably been beaten to death, nevertheless I hope
| you will still indulge me.
|
| During a power outage, which occurs frequently in Florida, I would like to
| use a battery to power some communication gear. Although the battery is
12v
| and not 13.8v, I think that the gear will still work OK (hopefully).
|
| Question 1. I believe that car batteries have a low internal resistance
| because their primary function is to provide a lot of current for a short
| time. There are other 12v large battery types that will last as long as a
| typical car battery. They are designed not to provide peak current, but to
| supply steady state current for a long time.
| For the life of me, I can't remember the name of those type batteries so I
| can't do a google to find a supplier. I hope this is making some sense.
|
| Question 2. Where can I find articles & schematics for a solar cell to
| provide a trickle charge for the aforementioned battery?
|
| Thank you very much.
|
| Cordially,
| west
|
|
On question 1: could you be referring to "Deep Cycle" batteries?

On 2005-11-18, west wrote:

I know this question has probably been beaten to death, nevertheless I hope
you will still indulge me.

During a power outage, which occurs frequently in Florida, I would like to
use a battery to power some communication gear. Although the battery is 12v
and not 13.8v, I think that the gear will still work OK (hopefully).

a typical 12V lead-acid battery is often 13.8v in practice.

Question 1. I believe that car batteries have a low internal resistance
because their primary function is to provide a lot of current for a short
time. There are other 12v large battery types that will last as long as a
typical car battery. They are designed not to provide peak current, but to
supply steady state current for a long time.
For the life of me, I can't remember the name of those type batteries so I
can't do a google to find a supplier. I hope this is making some sense.

"deep cycle"

Question 2. Where can I find articles & schematics for a solar cell to
provide a trickle charge for the aforementioned battery?

If you only want to trickle charge you can get pre-built solar trickle
chargers at many auto accessories stores. I see no reason why they would be
unsuitable for deep cycle batteries. OTOH it may be cheaper to trickle
charge from the mains.

Bye.
Jasen

On Sat, 19 Nov 2005 00:55:28 GMT, "west"
wrote:

I don't think so. They're the same large 12 batteries that have a steady
charge which lasts longer than a car battery. It's not designed to give a
huge initial surge current (to start a car or ?). More like regular
batteries that can take a charge. I wish I knew their name. I guess that's
why I posted in the first place.

west

You are describing a deep cycle battery. Designed to provide a lot of
amp hours of capacity, but not constructed to start a motor (although
they do that too - and can outlast regular car batteries)

I'm using a pair of Eagle Picher"Carefree" batteries (sealed
lead-acid) I've had since 1992 for hurricanes. They were made for
Minn Kota trolling motors and were sold as surplus. A pair of old 1
amp solar panels and a charge controller that was in the Amateur Radio
Handbook (shunt regulator built around a LM723).

I only run a TV, Radio, some lighting, and aquarium pumps with it.
--

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On 19 Nov 2005 12:03:33 -0800, wrote:

Greetings:
Yes, I think "Deep Cycle" or "Marine" type storage lead acid batteries
are what you are asking about. These batteries are not usualy intended
for starting, as mentioned before, although most can do so. They are
indeed better for constant current aplications.

---
Being voltage sources, I would have thought that they would be be
better suited to feed loads which relied on a constant-voltage,
variable current source.
---

(But so are 'regular car' batteries!) However, the real difference is this:
They are not distroyed by deep discharge like automotive starting batteries are.
(Leave your headlights on all day a few times, and you'll soon be
buying a new battery. Just ask my wife! )

---
Hogwash. If you grossly deplete the capacity of a lead-acid or
calcium-lead-acid battery by _any_ means, the battery will be
damaged. In order to keep that from happening, if your wife's
ignorance is the culprit, you need to train her up on the proper
operation of a motor vehicle.

That is, assuming you have a clue.
---

Thicker plates, along with a
few other minor tweeks, make them more RESISTANT to damage from deep
discharge. (NOT, totally indistructable!) The real difference, however,
is really one of degree... All the same 'rules' for one type apply to
the other. For example, leaving a storage battery of any kind in a
discharged condition for a long period of time is a killer. Keeping
either kind 'topped off' will drasticly improve life span. Discharge
RATE is also most important. Lower rates mean longer overall run time,
and less damage to battery. Also, there are so-called 'Dual Purpose'
types now being sold. Supposed to be good for starting, (Huge current
draw) AND for deep cycle (Deep discharge). Avoid these. Like anything
else, they are not really all that great at EITHER job. (Jack of all
trades, master of none)

---
Got data?
---

They are a compromise, and in some cases, they
are the EXACT same battery being sold by same company, but with a
different lable! (And warranty, usually)

---
Your point being...?
---

As for using HAM or similiar type mobile gear with a nominal 12 volt
battery, no problems. All modern gear is designed to be able to work
with the engine OFF, and anyways, a fully charged lead acid battery
dosen't actually measure out at 12 volts. Try this: Get a digital volt
meter, check a 12 volt battery that has a good level of charge still in
it. You will find that it more likely will measure 12.7 or so,
unloaded. Possibly more. (Depends on many variables, like state of
charge, age, temp, ect) Your 13.8 volt gear will never notice the
difference, trust me.

---
Trust you?

**** you.

So far you haven't demonstrated that you know what you're talking
about.
---

The 13.8 volts was orginally mandated by the FCC,
back before PLL and microcontroler radios. Reason was, the older types
of radios were sensitive to voltage differences, and frequency and/or
power output could drift or vary out of specs.

---
I guess you've never heard of a voltage regulator...
---

This is largely a moot
point now-a-days. Equipment had to be 'type certified" by the FCC at
13.8 volts, and all techs working on them had to use 13.8 volts when
making any adjustments or repairs, to avoid the above mentioned
problems. (Anyone remember "crystal ovens" ? They heated the 'rock' to
a specific temp, to avoid drift due to heat build-up) Who uses crystals
anymore? (OK, I know, we are still using them... But modern circuits
can compensate easily for temp rise/drift)

---
Got an example?
---

OK, having explained all that, as for the question of keeping your
stand by battery charged up and healthy, you could indeed do as
mentioned before by others, and that would be an easy way to go. Better
yet, buy a "Smart charger" to keep a float charge on the battery. It
won't over charge, and can be left on 24/7 without worry. (And will
cost pennies a month to run) However, here in the midwest, where I
live, power outtages are also common. (We get ice and snow storms as
well as tornadoes, thunderstorms, etc!) So MY solution was this: I had
a APC brand UPS in which the gel cell batteries died. I have found that
many people/companies throw these away when this happens, and they can
often be had for the hauling! (The new batteries would have cost me
over $150.00!)
What I did was this: My particular UPS used TWO batteries in series,
for 24 volts. It outputs a VERY clean sine waveform at 125 VAC. More to
the point, is ALSO keeps a trickle charge on the batteries. And being
"smart", it won't over charge. In a power outtage, this particular
model can keep any device plugged into it running without any hickup.
It's 'always on', no switching lag. So, you have two options here, one
is to power radios normally, via 125 vac, if you have that option, or
to use one or both backup batteries. You can either remove the backup
batteries from hookup to UPS, and use them stand alone, in parallel, or
single, one after the other. OR, just do as I do, and using a diode for
isolation, I use the 12 volts from one battery while it is still hooked
up to the UPS, while keeping the ability to have 125 vac available too.
(A heavy duty, fast recovery diode can do the job nicely, without much
forward drop, for free* (*Just canabalize an old computer power supply
for them. They come in "pairs" in a large transistor type package, are
VARY closely matched, being on one chip, and with the also included
heat sink, many can handle upwards of 20 to 40 amps EACH)
There you have it. Total standby solution. I bought TWO pairs of 12
volt deep cycle batteries, (About $60.00 each, for good ones) and,
along with the aforementioned UPS, I have 125 vac ready fulltime, as
well as plenty of 12 volt power. IF power outtage lasts a really long
time, I can recharge one set of batteries via automobile, if it comes
to that, while using the other set. Meantime, while NO power outtage
exists, one set is on the UPS, the other set is on 'smart chargers". I
also have 'regular' types of inverters, which use one battery, for
smaller tasks, like running a sawzall for cutting away downed tree
limbs. (These cheaper 'inverters' don't usally have a good sine
waveform, though) With 3 vehicles in the driveway, I have three more
batteries available for the inverter, and/or three more re-chargers.
Just be sure to run the engine from time to time. The inverter will
shut off before discharging battery too far.
(Our weather, and the remoteness of my location, has taught me valuable
lessons about being self reliant!)
One last thing: By re-cycling these UPS' rather than letting them go
into a landfill, you are helping the envioment. There are substances in
those devices, (And a lot of related gear too) that I'd rather NOT have
in my drinking water.

---
Like what, for instance?
---

Many locations reguard UPS' as hazardous waste,
even if old batteries have been removed.

---
Really?

Why would that be true? That is, if the UPS dies and its batteries
are removed and it's sent to the landfill, what would be hazardous
about its disposal?
---

(Take or send the old
batteries to a recycling station, or APC will accept them free, for
re-cycling, and/or proper disposal)
So you can help yourself, while helping everyone else too.
If you, or anyone reading this, has specific questions on this subject,
feel free to email, I'll try to help.

---
Your "help" will certainly be self-serving and email will only lock
the unsuspecting ignoranti into your line of reasoning without
exposing them to the truth.

Any questions should be sent to the newsgroup, where they can be
examined and debated, as opposed to being sent directly to you,
where you can use subterfuge to try to bend the querants' wills to
your own.


--
John Fields
Professional Circuit Designer

"default" wrote in message
...
On Sat, 19 Nov 2005 00:55:28 GMT, "west"
wrote:

I don't think so. They're the same large 12 batteries that have a steady
charge which lasts longer than a car battery. It's not designed to give a
huge initial surge current (to start a car or ?). More like regular
batteries that can take a charge. I wish I knew their name. I guess
that's
why I posted in the first place.

west

You are describing a deep cycle battery. Designed to provide a lot of
amp hours of capacity, but not constructed to start a motor (although
they do that too - and can outlast regular car batteries)

I'm using a pair of Eagle Picher"Carefree" batteries (sealed
lead-acid) I've had since 1992 for hurricanes. They were made for
Minn Kota trolling motors and were sold as surplus. A pair of old 1
amp solar panels and a charge controller that was in the Amateur Radio
Handbook (shunt regulator built around a LM723).

I only run a TV, Radio, some lighting, and aquarium pumps with it.
--

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That's what I'm looking for, Default. Do you have your panels in parallel?
What kind are they (voltage, name, etc.)? Also, would you happen to remember
the Amateur Handbook's year? Thank you.

west

On Sun, 20 Nov 2005 18:45:18 GMT, "west"
wrote:

That's what I'm looking for, Default. Do you have your panels in parallel?
What kind are they (voltage, name, etc.)? Also, would you happen to remember
the Amateur Handbook's year? Thank you.

west

My current copy 1990 doesn't show it so it must predate that.

It does show a typical linear shunt regulator sans parts values.

It also shows a more complicated solar charge controller that uses a
2N3055 in the negative leg of the panel to interrupt charging when
full charge is reached. Uses a 3 terminal regulator for a reference
and a 741 for a controller

The LM 723 has a reference and op amp in one package and Zener on the
output to compensate for the .6 volts out when the op amp is "off."
(Zener is on the 14 pin dip, the 10 pin TO5 doesn't have it)

http://www.jaycar.com.au/images_uploaded/LM723.PDF

Is the datasheet for the 723 and it shows a 5V regulator on page 10 -
you'd just have to change the reference.. That's the same circuit in
the handbook - but they used an adjustable setpoint, and an LED to
indicate when it was limiting the charge.

I have two 12 volt one amp panels in parallel. OC voltage is ~15
volts and it uses half circle cells ~18" X 20" I got them ages ago.
All it says on it is "sold as is" stamped into the silicon cladding on
the bottom. No idea of the manufacturer. The panels have a textured
heavy glass surface in a metal frame and appear to be something off a
really die- hard commercial application.

Download the data sheet. It is so simple . . . Only caveat - make
your heatsink up to the task of dissipating the heat. The LED is
handy too since you can set your charge with just a voltmeter on the
output - disconnect the battery you're charging and just set the
voltage to limit at.
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Well, you sure have a way with words, don't you? "**** you"? as a
reasoned response??

"Being voltage sources, I would have thought that they would be be
better suited to feed loads which relied on a constant-voltage,
variable current source"

It's fairly well known that any battery, any COMMON battery, will last
longer if the current demands on it are less that it's maximum possible
output. Period.

Hogwash. If you grossly deplete the capacity of a lead-acid or
calcium-lead-acid battery by _any_ means, the battery will be
damaged. In order to keep that from happening, if your wife's
ignorance is the culprit, you need to train her up on the proper
operation of a motor vehicle.

That is, assuming you have a clue.

The whole point of deep cycle batteries is that they can BETTER
withstand such treatment. I never claimed that it is GOOD for them.
(Now who dosen't have a clue?) As for my wife, I suppose YOUR superior
intelect has prevented you from EVER forgetting to turn off your
headlights. But the rest of us mere mortals have done it a time or two.
Watch what you say about peoples wives... Some people a touchy about
having jerks insult them.

"Got data? "

Sure, just go READ any manufacturer's data sheets.

"Your point being...?"

To give advice as to what to look for. The orginial poster was asking
about stand by power sources, and in my personal experience, that
advice was, and is, solid. I'll take experience over your snide flaming
anyday.

"Trust you?

**** you"

My my, for one with such an overblown vocabulary, such language.
Who the hell asked you for that, anyways? For that matter, who the
hell deserves that, from you, or anyone, when all they were trying to
do was to offer helpful advice? You apparently are intolerant of any
opinion other than your own. Must have had a bad day. By the way, I was
unaware that you personally owned this group.

"So far you haven't demonstrated that you know what you're talking
about. "

So, this is all about PROOF? I'm sure you are far more capable of
offering huge, scientific formulae than I am. I was offering advice,
not writing to a peer reviewed scientific journal.

"guess you've never heard of a voltage regulator... "

Sure I have. I said ORGINALLY... Back in the days of tubes. Voltage
regulators weren't so easy to come by. The days of one chip highly
accurate voltage regulators hadn't yet come.

"Got an example? "

Yea, look at the schematic of any modern gear... They have the
aforementioned voltage regulators in them. Guess you can't hold a
thought for more than one sentence.

"Really? "

Yes, really. They also often won't take computers, microwave ovens,
TVs, and a whole laundry list of other things.

"Why would that be true? That is, if the UPS dies and its batteries
are removed and it's sent to the landfill, what would be hazardous
about its disposal? "

Because they contain, among other things, lead, tin, copper, caustic
paste, (Capacitors) sometimes cadmium, nickel, and a lot of other
things that I wouldn't want in my drinking water. If you do, that's
fine with me. Around here, people are adverse to poisoning their
drinking water.

"Your "help" will certainly be self-serving and email will only lock
the unsuspecting ignoranti into your line of reasoning without
exposing them to the truth. "

You are out of your mind. How is anything I said "Self Serving"? I'm
not selling anything. Nor am I trying to convert anyone's "line of
reasoning" to anything. Exposing them to what TRUTH? (And what "THEM? I
was replying to ONE person!)
What I did was, I offered the benefit of my experience, nothing more or
less. Apparently, the only TRUTH you are concerned about is your own.
I'm not trying to PROVE anything. So, you calling me a liar or what?
Man, you are one paranoid son of a bitch.

"Any questions should be sent to the newsgroup, where they can be
examined and debated, as opposed to being sent directly to you,
where you can use subterfuge to try to bend the querants' wills to
your own. "


Fine, if you want to see the same subject "Beaten to death". as the
original poster put it.
As for the email thing, I was NOT trying to avoid anything, other than
clogging up the group with repetitive questions.
What I WAS trying to do was: Be helpful. But not to worry, I'll never
make THAT mistake again. I misunderstood the purpose of the whole
'groups" concept. I was unaware that it was the personal domain of a
single GODlike egomaniac.

You apparently like to show off your vocabulary, (Even to the point of
proving, as you like to do, that you know how to use vulgarity to
insult) But I assure you, I have no interest in using "Subterfuge" to
bend anyone's will to anything: Again, I'm NOT selling anything. You
give me too much credit... I doubt very much if I could "use subterfuge
to try to bend the querants' wills to your own. "

WHY the hell would I even WANT to do such a thing?
You must think I'm some sort of hypnotist, and that I can work my magic
through email. If that were true, I'd be rich.

But, since you are SUCH an expert on everything under the sun, I'll
just let you answer everything. Jerk.

If you intended to shoo away any new people, you are well on your way
to getting your wish. Too bad you aren't here in person, because where
I come from, people who offer un-called for insults to a man's wife and
utter 'fighting words' is likely to get a whole new kind of
'education'.
And finally, since I wasn't even talking to you to begin with, who
cares? Youv'e proven, and you seem to love your proofs, what you are
really made of.
Bye bye. I can get insulted in anyone of several thousands of other
groups. This one has nothing to offer me that I can't get elsewhere.
Junkman

"west" wrote in message
...
I know this question has probably been beaten to death, nevertheless I
hope
you will still indulge me.

During a power outage, which occurs frequently in Florida, I would like to
use a battery to power some communication gear. Although the battery is
12v
and not 13.8v, I think that the gear will still work OK (hopefully).

Question 1. I believe that car batteries have a low internal resistance
because their primary function is to provide a lot of current for a short
time. There are other 12v large battery types that will last as long as a
typical car battery. They are designed not to provide peak current, but to
supply steady state current for a long time.
For the life of me, I can't remember the name of those type batteries so I
can't do a google to find a supplier. I hope this is making some sense.


You are correct in noting that car batteries are, as a rule, designed to
deliver high current; long life is a secondary consideration. The way that
this is done is by using thin plates close together which gives lots of
surface area and hence lots of current. Such batteries do not tolerate
discharges well, it lessens their life considerably as the thin plates can
develop "holes" over time as they are depleted. Deep cycle batteries are
designed to supply less current for a longer duration and tolerate discharge
to 50-70% or so fairly well. They have thicker plates. Typical uses are
RV's and boats, which use lights, TV's, instruments, etc. without the engine
running quite a lot. I have been talking of lead-acid batteries here.
Another type is gel-cells. Gel cells contain the electrolytic solution
suspended in a "gel" which allows them to be fully discharged without
shorting out the plates and ruining the batteries... the gel holds the lead
ions from precipitating out of solution as the battery is discharged. Gel
cells must be charged at a slower rate, and cannot deliver as much current
as lead-acid, but they are extremely tolerant of discharge, they are hard to
ruin. Many offshore sailors including myself use 6V golf cart batteries
which are designed to put out a moderate constant current for A LONG TIME.
You can wire two in series to give you your 12VDC. Just for fun, another
type of battery is the AGM, or associated glass mat. They are the best of
gel cells AND wet cells; they were developed for use in fighter jets where
they are often upside down and subjected to multi-G forces. They are,
unfortunately, also extremely expensive and hard to come by.

Question 2. Where can I find articles & schematics for a solar cell to
provide a trickle charge for the aforementioned battery?

Google for solar chargers, they are available at most marine stores too and
not particularly expensive. I'd guess buying one would be considerable
cheaper and more reliable than what you might be able to build.

Thank you very much.

Cordially,
west