high current voltage regulator

[Laurie]

I have solar panels charging two deep-cycle 12 V PbA batteries. When
reasonably well charged the voltage goes up to ~16.5, but the inverter I am
using stupidly shuts down around 14+.

I would like to know if there is a single package voltage regulator that
will handle 10-15 amps.

If not, can someone recommend a circuit?

Laurie

 

[mike]

Laurie wrote:

I have solar panels charging two deep-cycle 12 V PbA batteries. When
reasonably well charged the voltage goes up to ~16.5, but the inverter I am
using stupidly shuts down around 14+.

I would like to know if there is a single package voltage regulator that
will handle 10-15 amps.

If not, can someone recommend a circuit?

Laurie

Are you sure you want to cook the batteries at 16.5V? How much extra
usable capacity do you get? The whole purpose of the charger is to
PREVENT overcharging.

If you insist, wouldn't it be easier to just fix the inverter?

Once built a current dump load using a PWM, some big resistors and PIC.
Avoids all those nasty voltage drops in series with the solar panels.

You'll probably get better info on one of the alternative energy groups.
mike

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[Laurie]

"mike" <spamme0@netscape.net> wrote in message
news:42587A63.4050504@netscape.net...

Are you sure you want to cook the batteries at 16.5V?
The manufacturer recommends 16.3 v for several hours, I just pulled the

16.5 out of my tortured memory.

The whole purpose of the charger is to PREVENT overcharging.
No "charger".

If you insist, wouldn't it be easier to just fix the inverter?
It came that way, I assumed it was some sort of 'protection', not a

manufacturing flaw.

Once built a current dump load using a PWM, some big resistors and PIC.
Irrelevant, the point was to regulate the -voltage- across the inverter,

while simultaneously topping off the batteries.

You'll probably get better info on one of the alternative energy groups.
Since this is "components" and the regulator is one, I foolishly

assumed...

Laurie

 

"Watson A.Name - \"Watt Sun, the Dark Remover\""
<NOSPAM@dslextreme.com> wrote:

For some odd reason the bridge rectifiers are priced oddly compared to
the rectifiers.

Could that be due to the fact that the bridge is (nearly always) going
to be used at a 50% duty cycle, while discrete diodes might be used at
100%? [And there's probably some packaging savings...]

 

[EN]

<ehsjr@bellatlantic.net> wrote in message
news:Ft26e.3783$ff4.1779@trndny08...

Laurie wrote:

I have solar panels charging two deep-cycle 12 V PbA batteries. When
reasonably well charged the voltage goes up to ~16.5, but the inverter I
am
using stupidly shuts down around 14+.
.... snip ..

Finally, and *most* important: you need to know the
charging requirements of the batteries if you are going
to make a regulator to charge them. "Around 14 volts"
sounds more "right" than "several hours at 16.3 volts" ,
but neither one instills a lot of confidence. I believe -
but do not know for sure - that in solar systems a periodic
overcharge (called an equalization charge) is sometimes
recommended. That should certainly not be done on
a regular basis. 16.3 is an overcharge - perhaps it is
that equalization charge I've heard about.

Ed

If I recall.. an equalization charge has to do with UPS systems.
Uninterupable Power Supply with alot of 2V batteries, or cells.
Some cells will be lower in votage and some maybe higher.
1.95 ... 2.00 ... 2.3 ... 2.01 ... 2.00
You apply a charging voltage of 2.25 volts to all the cells.
The charging voltage is the equalization charge voltage.
You are bringing all low cells up in voltage and the hi cells down,
till all the cells are at a certain voltage, fro the whole UPS system.
I'm sure of the 2.25 volts, maybe I'm wrong on this, just some
number in my head rite now.

 

[EN]

"mike" <spamme0@netscape.net> wrote in message
news:42587A63.4050504@netscape.net...

Laurie wrote:
I have solar panels charging two deep-cycle 12 V PbA batteries.
When
reasonably well charged the voltage goes up to ~16.5, but the inverter I
am
using stupidly shuts down around 14+.

I would like to know if there is a single package voltage regulator
that
will handle 10-15 amps.

If not, can someone recommend a circuit?

Laurie

You can use 2 higher rated diodes, or you can use a bridge rectifier that
has 4 diodes in the package.

ebay , BRIDGE RECTIFIER 25 AMPS NEW OLD STOCK , $1.00

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=73142&item=7505683415&rd=1

 

[Watson A.Name - \"Watt Su]

"EN" <res808c4@earthlink.net> wrote in message
news:_J36e.3338$go4.717@newsread2.news.atl.earthlink.net...

ehsjr@bellatlantic.net> wrote in message
news:Ft26e.3783$ff4.1779@trndny08...
Laurie wrote:

I have solar panels charging two deep-cycle 12 V PbA batteries.
When
reasonably well charged the voltage goes up to ~16.5, but the
inverter I
am
using stupidly shuts down around 14+.
... snip ..

Finally, and *most* important: you need to know the
charging requirements of the batteries if you are going
to make a regulator to charge them. "Around 14 volts"
sounds more "right" than "several hours at 16.3 volts" ,
but neither one instills a lot of confidence. I believe -
but do not know for sure - that in solar systems a periodic
overcharge (called an equalization charge) is sometimes
recommended. That should certainly not be done on
a regular basis. 16.3 is an overcharge - perhaps it is
that equalization charge I've heard about.

Ed

If I recall.. an equalization charge has to do with UPS systems.
Uninterupable Power Supply with alot of 2V batteries, or cells.
Some cells will be lower in votage and some maybe higher.
1.95 ... 2.00 ... 2.3 ... 2.01 ... 2.00
You apply a charging voltage of 2.25 volts to all the cells. B
The charging voltage is the equalization charge voltage.
You are bringing all low cells up in voltage and the hi cells down,
till all the cells are at a certain voltage, fro the whole UPS system.
I'm sure of the 2.25 volts, maybe I'm wrong on this, just some
number in my head rite now.

The 2.25V is the float charge voltage; eq V is a bit more, like 2.3 or
so. But most UPSes don't have parallel batteries, they are in series.
So enough current is run thru them all to give the eq v across each,
which means that the cells with higher V are also overcharged.

 

[EN]

"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com> wrote
in message news:115ih7s52292af6@corp.supernews.com...

"EN" <res808c4@earthlink.net> wrote in message
news:_J36e.3338$go4.717@newsread2.news.atl.earthlink.net...

ehsjr@bellatlantic.net> wrote in message
news:Ft26e.3783$ff4.1779@trndny08...
Laurie wrote:

I have solar panels charging two deep-cycle 12 V PbA batteries.
When
reasonably well charged the voltage goes up to ~16.5, but the
inverter I
am
using stupidly shuts down around 14+.
... snip ..

Finally, and *most* important: you need to know the
charging requirements of the batteries if you are going
to make a regulator to charge them. "Around 14 volts"
sounds more "right" than "several hours at 16.3 volts" ,
but neither one instills a lot of confidence. I believe -
but do not know for sure - that in solar systems a periodic
overcharge (called an equalization charge) is sometimes
recommended. That should certainly not be done on
a regular basis. 16.3 is an overcharge - perhaps it is
that equalization charge I've heard about.

Ed

If I recall.. an equalization charge has to do with UPS systems.
Uninterupable Power Supply with alot of 2V batteries, or cells.
Some cells will be lower in votage and some maybe higher.
1.95 ... 2.00 ... 2.3 ... 2.01 ... 2.00
You apply a charging voltage of 2.25 volts to all the cells. B
The charging voltage is the equalization charge voltage.
You are bringing all low cells up in voltage and the hi cells down,
till all the cells are at a certain voltage, fro the whole UPS system.
I'm sure of the 2.25 volts, maybe I'm wrong on this, just some
number in my head rite now.

The 2.25V is the float charge voltage; eq V is a bit more, like 2.3 or
so. But most UPSes don't have parallel batteries, they are in series.
So enough current is run thru them all to give the eq v across each,
which means that the cells with higher V are also overcharged.

"> But most UPSes don't have parallel batteries, they are in series."


I had to look , so series / parallel UPS , google has 190,000 hits
http://www.aelgroup.co.uk/hb/hb730.htm

Alpha UPS units use both series and parallel combinations...
http://206.131.241.58/ubb/ultimatebb.php?ubb=get_topic&f=1&t=002710

"Connecting your Batteries in Series or Parallel"
http://www.zbattery.com/zbattery/seriesparallel.html

Series-Parallel Connection with a 12 Volt 1 Amp BatteryMINDer
http://www.batteryweb.com/batteryminder-multiple-batteries.cfm

+186,000 web links to go for Series/Parallel configurations.
Seems there's more ways to skin a cat.

 

[EN]

ehsjr@bellatlantic.net> wrote in message
news:Ft26e.3783$ff4.1779@trndny08...
Laurie wrote:

I have solar panels charging two deep-cycle 12 V PbA batteries.
When reasonably well charged the voltage goes up to ~16.5,
but the inverter I'm using stupidly shuts down around 14+.
... snip ..

Finally, and *most* important: you need to know the
charging requirements of the batteries if you are going
to make a regulator to charge them. "Around 14 volts"
sounds more "right" than "several hours at 16.3 volts" ,
but neither one instills a lot of confidence. I believe -
but do not know for sure - that in solar systems a periodic
overcharge (called an equalization charge) is sometimes
recommended. That should certainly not be done on
a regular basis. 16.3 is an overcharge - perhaps it is
that equalization charge I've heard about.

Ed

The battery faq is, http://www.uuhome.de/william.darden/

CAR AND DEEP CYCLE BATTERY
FREQUENTLY ASKED QUESTIONS 5.2 ,
http://www.uuhome.de/william.darden/carfaq.htm

Battery Tutorial , http://www.batterystuff.com/tutorial_battery.html

It looks like the 14 volts is what's suppose to be there.
If you over charge a battery with more than 14 volts, you might risk
damaging the battery. Aren't deep cycle batteries expensive?

Ed

 

[Peter Bennett]

On Sat, 9 Apr 2005 16:21:42 -1000, "Laurie" <no@spam.com> wrote:

"mike" <spamme0@netscape.net> wrote in message
news:42587A63.4050504@netscape.net...

Are you sure you want to cook the batteries at 16.5V?
The manufacturer recommends 16.3 v for several hours, I just pulled the
16.5 out of my tortured memory.

For a 12 volt lead-acid battery, 16.3 volts is an equalizing charge,
and should only be done occasionally. Normal bulk charging is done at
up to 14.4 volts (or so, depending on temperature). As the battery
approaches full charge, the voltage should be reduced to a "float"
level of aboout 13.7 volts - otherwise you'll boil off all the
electrolyte.

--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

[Byron A Jeff]

In article <425868dc$1_5@alt.athenanews.com>, Laurie <no@spam.com> wrote:

I have solar panels charging two deep-cycle 12 V PbA batteries. When
reasonably well charged the voltage goes up to ~16.5,

but the inverter I am using stupidly shuts down around 14+.

I have but a single question...

Why do you think that it's stupid that the inverter shuts down at 14V?

I think it's smart enough to realize that you're cooking your batteries at
16.5V.

Do you?

BAJ

 

[Dave Platt]

In article <lvej51ho7329q8557jh73ejpstj8t8roka@news.supernews.com>,
Peter Bennett <peterbb@somewhere.invalid> wrote:

For a 12 volt lead-acid battery, 16.3 volts is an equalizing charge,
and should only be done occasionally.

As I understand it, the equalizing charge is intended to mix up the
electrolyte. In a flooded-cell lead-acid battery, the electrolyte can
"stratify" into layers of different density - high-density high-acid
fractions at the bottom, and a more dilute electrolyte at the top of
the battery. This stratification can impair the battery's ability to
charge and discharge properly. The equalizing charge _deliberately_
pushes the battery into electrolysis, breaking down some of the
electrolyte's water into hydrogen and oxygen. The resulting
plop-plop-fizz-fizz stirs up the electrolyte and de-stratifies it.

The cost of doing this, of course, is a loss of water in the cells.
The battery's gas-recombination catalyst _might_ be able to recombine
all of the hydrogen and oxygen into water, but I suspect that it
usually can't keep up with the gas flow and that the excess gasses are
lost.

Again as I understand it, gel cells do not require equalizing, and AGM
(glassmat) batteries neither require it nor can tolerate it (they can
be damaged by high charging voltage). I don't think I'd equalize-
charge any sealed lead-acid battery unless the manufacturer
specifically recommended doing so and gave explicit instructions on
voltage and duration. Over-pressuring a sealed battery case could
have nasty results.

One manufacturer of deep-discharge flooded-cell batteries suggests one
equalizing charge per 10 deep discharges.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

 

[mc]

"mike" <spamme0@netscape.net> wrote in message
news:42587A63.4050504@netscape.net...

Laurie wrote:
I have solar panels charging two deep-cycle 12 V PbA batteries. When
reasonably well charged the voltage goes up to ~16.5, but the inverter I
am using stupidly shuts down around 14+.

Shutting down at 14.1 volts is correct for 12-volt lead-acid batteries. I
wouldn't change it.

 

[mc]

"mc" <mc_no_spam@uga.edu> wrote in message
news:4258a4ce@mustang.speedfactory.net...

"mike" <spamme0@netscape.net> wrote in message
news:42587A63.4050504@netscape.net...
Laurie wrote:
I have solar panels charging two deep-cycle 12 V PbA batteries.
When reasonably well charged the voltage goes up to ~16.5, but the
inverter I am using stupidly shuts down around 14+.

Shutting down at 14.1 volts is correct for 12-volt lead-acid batteries. I
wouldn't change it.

I think I misunderstood the question. A charger should shut down (reduce
its current to a trickle) when the battery reaches 14.1 volts. Or are you
saying that an inverter (that takes the battery's output to higher-voltage
AC) is shutting down when its input is over 14 volts?

 

Laurie wrote:

I have solar panels charging two deep-cycle 12 V PbA batteries. When
reasonably well charged the voltage goes up to ~16.5, but the inverter I am
using stupidly shuts down around 14+.

I would like to know if there is a single package voltage regulator that
will handle 10-15 amps.

If not, can someone recommend a circuit?


I think you want to look for a solar charge controller, rather than a

voltage regulator. It's a simple matter to make a regulator
with an LM317 and pass transistors, similar to this:
http://ourworld.compuserve.com/homepages/Bill_Bowden/page12.htm
(The circuit shown woud have to be modified for your use)
The problem is that your energy source is solar, and the panels
may not (probably do not) produce enough voltage for that
kind of circuit.

For a solar charge controller, you really want an inverter
style supply, which can produce the required charging
voltage even when the panels can provide a voltage
well below that.

Finally, and *most* important: you need to know the
charging requirements of the batteries if you are going
to make a regulator to charge them. "Around 14 volts"
sounds more "right" than "several hours at 16.3 volts" ,
but neither one instills a lot of confidence. I believe -
but do not know for sure - that in solar systems a periodic
overcharge (called an equalization charge) is sometimes
recommended. That should certainly not be done on
a regular basis. 16.3 is an overcharge - perhaps it is
that equalization charge I've heard about.

Ed

Laurie

 

[Watson A.Name - \"Watt Su]

"Laurie" <no@spam.com> wrote in message
news:425868dc$1_5@alt.athenanews.com...

I have solar panels charging two deep-cycle 12 V PbA batteries.
When
reasonably well charged the voltage goes up to ~16.5, but the inverter
I am
using stupidly shuts down around 14+.

I would like to know if there is a single package voltage
regulator that
will handle 10-15 amps.

If not, can someone recommend a circuit?

Laurie

You can buy a 25A bridge reectifier for under $3.00. When you short the
+ and- leads, the ~ leads will drop at least 1.2V, more as the current
goes up. The polarity doesn't matter, of course. Or you could use 1 or
2 rectifiers in series, each dropping about .8V depending on current.
butthey're probably more expensive than the bridge. A 1N1188A 35 amp
stud mount is aboutthe same prices as the bridge, but you need two of
them.

For some odd reason the bridge rectifiers are priced oddly compared to
the rectifiers. 1A, 3A and 6A rectifiers are $.04, $.12 and $.22
apiece. Those prices hover around a nickel an amp. But the prices for
bridges hover around a quarter an amp, and don't drop as quickly at
higher currents.