Larry, if you read this.

Am embroiled in a discussion about solar panel controllers.

Aside from the fact that smaller arrays of panes don't put out enough
amperage to over charge a medium bank of batteries, can you comment on
what type of regulator is usually best. I have seen both shunt
regulators and others that simply open either the positive or negative
leg between the panel and the battery, which seems a simpler method. I
have also seen a home-brew regulator the shorted the legs together,
but that seems sort of brutal to me.

It appears to me that a simple voltage sensor and a solid state switch
is all that is needed, but perhaps I can't see the forest for the
trees as regulators, over here, cost a hundred bucks, or more.

Cheers,

Bruce

On Jan 26, 4:21 am, BruceinBangkok wrote:
Larry, if you read this.

Am embroiled in a discussion about solar panel controllers.

Aside from the fact that smaller arrays of panes don't put out enough
amperage to over charge a medium bank of batteries, can you comment on
what type of regulator is usually best. I have seen both shunt
regulators and others that simply open either the positive or negative
leg between the panel and the battery, which seems a simpler method. I
have also seen a home-brew regulator the shorted the legs together,
but that seems sort of brutal to me.

It appears to me that a simple voltage sensor and a solid state switch
is all that is needed, but perhaps I can't see the forest for the
trees as regulators, over here, cost a hundred bucks, or more.

Cheers,

Bruce

My 2 cents worth, skip the regulator. Costly and in my experience,
unnecessary if your panel power output capability is small compared to
your battery AH. I use a 2 amp panel on 8D diesel starting batteries,
no regulator, zero problems. If you are getting into bigger panels why
pay $70-100 for a regulator? Just use an IC voltage regulator. Sure,
you'll lose some power in heat, but you wont over charge if you keep
the voltage below about 13.8 VDC or so. You can rig these ICs to
control external power transistors if you are dealing with current in
excess of the IC ratings.

Some top end solar panel regulators are very sophisticated and can
actually boost voltage to eek out a tiny charge during a sunset, but
thats not needed in my application.

Mark
SF CA

On Tue, 27 Jan 2009 00:41:37 -0800 (PST), 377
wrote:

On Jan 26, 4:21 am, BruceinBangkok wrote:
Larry, if you read this.

Am embroiled in a discussion about solar panel controllers.

Aside from the fact that smaller arrays of panes don't put out enough
amperage to over charge a medium bank of batteries, can you comment on
what type of regulator is usually best. I have seen both shunt
regulators and others that simply open either the positive or negative
leg between the panel and the battery, which seems a simpler method. I
have also seen a home-brew regulator the shorted the legs together,
but that seems sort of brutal to me.

It appears to me that a simple voltage sensor and a solid state switch
is all that is needed, but perhaps I can't see the forest for the
trees as regulators, over here, cost a hundred bucks, or more.

Cheers,

Bruce

My 2 cents worth, skip the regulator. Costly and in my experience,
unnecessary if your panel power output capability is small compared to
your battery AH. I use a 2 amp panel on 8D diesel starting batteries,
no regulator, zero problems. If you are getting into bigger panels why
pay $70-100 for a regulator? Just use an IC voltage regulator. Sure,
you'll lose some power in heat, but you wont over charge if you keep
the voltage below about 13.8 VDC or so. You can rig these ICs to
control external power transistors if you are dealing with current in
excess of the IC ratings.

Some top end solar panel regulators are very sophisticated and can
actually boost voltage to eek out a tiny charge during a sunset, but
thats not needed in my application.

Mark
SF CA

I thought I mentioned that small arrays of panels couldn't over charge
a bank of batteries :-)

I was asking about the preferred type of regulator, i.e., shunt, open-
close circuit, short circuit.

My own boat has three panels charging a medium size bank and never
gets above 13.5 V. On the other hand it will only run a DC fridge if
the sun shines all day, every day.
Cheers,

Bruce

BruceinBangkok wrote in
:

I was asking about the preferred type of regulator, i.e., shunt, open-
close circuit, short circuit.

If you look at the cells on a heavily loaded panel, notice how brown they
get overheating in the noonday sun so quickly? That should answer your
above question. ANYTHING you can do, like DISCONNECT (read that series
open circuit regulators) an unneeded solar panel in the hot hot sun to GET
THE CELL TEMPERATURE DOWN is always a GOOD thing. The way to get the heat
down is to LOWER, not raise, the cell current. That part of the cells that
don't have any current going through them never seems to change from that
blue silicon color to that brown, scorched-earth look. It's the CURRENT
that fries them. Shunt regulators simply drive up the cell current, which
drives up the cell HEATING until the cell fails....making the cell salesmen
simply smile. Shunt regulators are for suckers.....

My own boat has three panels charging a medium size bank and never
gets above 13.5 V. On the other hand it will only run a DC fridge if
the sun shines all day, every day.
Cheers,


If you can still get a sun tan on a 40' boat who's charging is solar panels
running a fridge with no wind charger....the fridge will easily keep the
cells from overcharging the battery. It's really hard to develop enough
power to fry a LOADED battery with solar cells. BUT...NEVER LEAVE THE BOAT
BATTERIES CONNECTED TO SOLAR PANELS WITHOUT A LOAD!....that'll fry it over
a week.

All solar chargers on boats seem to suck....about like those boat fans
buzzing away over your bunk....cheap crap. But, I'd never use a shunt
controller as it fries the cells in a hot sun at low latitudes. They all
turn BROWN where the current flows!

I've never seen a solar cell fried in the sun unloaded......even in the
Iranian desert mountains.

Larry wrote in
:

BruceinBangkok wrote in
:

I was asking about the preferred type of regulator, i.e., shunt,
open- close circuit, short circuit.

If you look at the cells on a heavily loaded panel, notice how brown
they get overheating in the noonday sun so quickly? That should
answer your above question. ANYTHING you can do, like DISCONNECT
(read that series open circuit regulators) an unneeded solar panel in
the hot hot sun to GET THE CELL TEMPERATURE DOWN is always a GOOD
thing. The way to get the heat down is to LOWER, not raise, the cell
current. That part of the cells that don't have any current going
through them never seems to change from that blue silicon color to
that brown, scorched-earth look. It's the CURRENT that fries them.
Shunt regulators simply drive up the cell current, which drives up the
cell HEATING until the cell fails....making the cell salesmen simply
smile. Shunt regulators are for suckers.....

My own boat has three panels charging a medium size bank and never
gets above 13.5 V. On the other hand it will only run a DC fridge if
the sun shines all day, every day.
Cheers,


If you can still get a sun tan on a 40' boat who's charging is solar
panels running a fridge with no wind charger....the fridge will easily
keep the cells from overcharging the battery. It's really hard to
develop enough power to fry a LOADED battery with solar cells.
BUT...NEVER LEAVE THE BOAT BATTERIES CONNECTED TO SOLAR PANELS WITHOUT
A LOAD!....that'll fry it over a week.

All solar chargers on boats seem to suck....about like those boat fans
buzzing away over your bunk....cheap crap. But, I'd never use a shunt
controller as it fries the cells in a hot sun at low latitudes. They
all turn BROWN where the current flows!

I've never seen a solar cell fried in the sun unloaded......even in
the Iranian desert mountains.

I must be confused by what you wrote. You're stating that solar cells
turn brown if they're loaded?!? What solar arrays have you seen that
aren't loaded? And if so, why where they installed? I've rarely seen a
case where the entire output of an array hasn't been needed/used other
than when a boat was at dock.

Personally I use a diversion controller since it handles both my wind
generator and solar panels and the wind generator has to have a load to
keep it from free-wheeling.

I've been very happy with my Morningstar Tri-star controller, but have
nothing but bad experiences with Xantrex C-40 controllers.

-- Geoff
www.GeoffSchultz.org

Geoff Schultz wrote in
:

I must be confused by what you wrote. You're stating that solar cells
turn brown if they're loaded?!? What solar arrays have you seen that
aren't loaded? And if so, why where they installed? I've rarely seen
a
case where the entire output of an array hasn't been needed/used other
than when a boat was at dock.

Personally I use a diversion controller since it handles both my wind
generator and solar panels and the wind generator has to have a load
to
keep it from free-wheeling.

I've been very happy with my Morningstar Tri-star controller, but have
nothing but bad experiences with Xantrex C-40 controllers.



Wind generators need shunt controllers to keep them from freewheeling
and throwing the blades off. We're talking, here, about SOLAR PANELS
and I'll stick to that.

Any solid state device, including solar panels, have one enemy, HEAT!
They fry from the heat. This causes doping migration across the
junction. A solar panel is simply a 2-pole diode exposed so photons can
drive electrons across the junction. It's why you always have a
blocking diode because it will conduct like a diode the other way
discharging the battery at night or in clouds.

Heat cooking common solar panels is easily seen in the area of each cell
where the current flows through the device, leaving the area around the
edges where no current flows its original metallic blue color. The
current area of the cell gets browner and browner as it ages and the
heat causes the cell's fundamental chemistry to change, lowering output.
Look at any old solar panel that's been pumping out the amps for a few
years and you can see it.

Now, the batteries are charged and the solar array in the hot noonday
sun is attempting to crank out its 19V open circuit voltage. The common
shunt regulator simply loads down the solar cell with a shunt resistance
to cause the array's inherent series resistance to absorb the difference
between the array's open circuit voltage, around 19V and the desired
float voltage of 14.2V for 12V lead-acid house batteries. Let's do some
simple math...19 - 14.2 = 4.8 volts dropped inside the series of cells x
whatever total current the array is cranking out in the hot, direct sun
say 10A for simplicity = 48 WATTS of heat MORE than what the natural no-
current temperature rise of the panels is with no load current. 48
watts is a fairly good amount of heat when concentrated in that little
circle that's turning brown in the middle of the cells. Don't think so?
Try this. take a contact thermometer or an infrared thermometer that
can measure the temp of the cells UNPLUGGED in that hot sun. Now, plug
it into the combination of shunt controller/battery in its normal
connection. Watch the temperature of the cells rise with that 48W of
heat across the panels. It's a serious amount. Leave that running a
few years at 6-7 hours on sunny days.

Why go to all that when it's SO easy to put in a SERIES controller that
will simply SWITCH OFF the power at 14.2V and switch it back on, again,
at 13.2V just like a good battery charger? Why make the cells so HOT?!
Unlike the windcharger which NEEDS the load current to slow it down from
overspeed....solar cells DON'T!

http://www.solazone.com.au/Regulators.htm
Why not install a multistage series regulator that charges up the house
batteries EXACTLY like your multistage AC charger does?

http://www.arrid.com.au/?act=Solar%20Regulators

http://www.marinewarehouse.net/blueskyenergy.html

http://www.wirefreedirect.com/mornin...ontrollers.asp
"These products are well known for their reliability and ability to
extend battery life and capacity through their PWM - Pulse Width
Modulation technology - the battery is continually poled (pulsed) so
maintaining the battery in a fully topped up state and ensures the
voltage remains constant. This method ensures that the battery
receives maximum charge, whilst preventing overcharging. The
Morningstar range range of solar controllers charge controllers are
famous for their superior quality of construction reliability. "

Constant voltage, PULSED charging....just like your AC charger at the
dock.

Larry wrote in
:

Geoff Schultz wrote in
:

I must be confused by what you wrote. You're stating that solar
cells turn brown if they're loaded?!? What solar arrays have you
seen that aren't loaded? And if so, why where they installed? I've
rarely seen
a
case where the entire output of an array hasn't been needed/used
other than when a boat was at dock.

Personally I use a diversion controller since it handles both my wind
generator and solar panels and the wind generator has to have a load
to
keep it from free-wheeling.

I've been very happy with my Morningstar Tri-star controller, but
have nothing but bad experiences with Xantrex C-40 controllers.



Wind generators need shunt controllers to keep them from freewheeling
and throwing the blades off. We're talking, here, about SOLAR PANELS
and I'll stick to that.

Any solid state device, including solar panels, have one enemy, HEAT!
They fry from the heat. This causes doping migration across the
junction. A solar panel is simply a 2-pole diode exposed so photons
can drive electrons across the junction. It's why you always have a
blocking diode because it will conduct like a diode the other way
discharging the battery at night or in clouds.

Heat cooking common solar panels is easily seen in the area of each
cell where the current flows through the device, leaving the area
around the edges where no current flows its original metallic blue
color. The current area of the cell gets browner and browner as it
ages and the heat causes the cell's fundamental chemistry to change,
lowering output. Look at any old solar panel that's been pumping out
the amps for a few years and you can see it.

Now, the batteries are charged and the solar array in the hot noonday
sun is attempting to crank out its 19V open circuit voltage. The
common shunt regulator simply loads down the solar cell with a shunt
resistance to cause the array's inherent series resistance to absorb
the difference between the array's open circuit voltage, around 19V
and the desired float voltage of 14.2V for 12V lead-acid house
batteries. Let's do some simple math...19 - 14.2 = 4.8 volts dropped
inside the series of cells x whatever total current the array is
cranking out in the hot, direct sun say 10A for simplicity = 48 WATTS
of heat MORE than what the natural no- current temperature rise of the
panels is with no load current. 48 watts is a fairly good amount of
heat when concentrated in that little circle that's turning brown in
the middle of the cells. Don't think so? Try this. take a contact
thermometer or an infrared thermometer that can measure the temp of
the cells UNPLUGGED in that hot sun. Now, plug it into the
combination of shunt controller/battery in its normal connection.
Watch the temperature of the cells rise with that 48W of heat across
the panels. It's a serious amount. Leave that running a few years at
6-7 hours on sunny days.

Why go to all that when it's SO easy to put in a SERIES controller
that will simply SWITCH OFF the power at 14.2V and switch it back on,
again, at 13.2V just like a good battery charger? Why make the cells
so HOT?! Unlike the windcharger which NEEDS the load current to slow
it down from overspeed....solar cells DON'T!

http://www.solazone.com.au/Regulators.htm
Why not install a multistage series regulator that charges up the
house batteries EXACTLY like your multistage AC charger does?

http://www.arrid.com.au/?act=Solar%20Regulators

http://www.marinewarehouse.net/blueskyenergy.html

http://www.wirefreedirect.com/mornin...ontrollers.asp
"These products are well known for their reliability and ability to
extend battery life and capacity through their PWM - Pulse Width
Modulation technology - the battery is continually poled (pulsed) so
maintaining the battery in a fully topped up state and ensures the
voltage remains constant. This method ensures that the battery
receives maximum charge, whilst preventing overcharging. The
Morningstar range range of solar controllers charge controllers are
famous for their superior quality of construction reliability. "

Constant voltage, PULSED charging....just like your AC charger at the
dock.

I understand how the various types of regulators work. What amazed me
was your statement about utilizing a type of regulator to avoid placing a
load on the solar cells to keep them from turning brown.

You've spent too much time at a dock if you think that's a problem for a
cruising boat or any household system, as the demands typically outstrip
generated supply and you're sucking every watt that the panels can make.
If you're not using them, why waste the money installing them?

For me, my panels get disconnected when I pull into dock for extended
stays, and for short stays the excess power goes to heating water, so I'm
being "green."

-- Geoff
www.GeoffSchultz.org

If you have more than one panel you need to look at MPPT controllers

On Wed, 28 Jan 2009 14:46:25 -0800 (PST), Peter
wrote:

If you have more than one panel you need to look at MPPT controllers

Why?
Cheers,

Bruce

Since you are posting in a public forum, it would be better to use a
more meaningful Subject. Thanks.

On Mon, 26 Jan 2009 19:21:05 +0700, BruceinBangkok
wrote in
:


Larry, if you read this.

Am embroiled in a discussion about solar panel controllers.

Aside from the fact that smaller arrays of panes don't put out enough
amperage to over charge a medium bank of batteries, can you comment on
what type of regulator is usually best. I have seen both shunt
regulators and others that simply open either the positive or negative
leg between the panel and the battery, which seems a simpler method. I
have also seen a home-brew regulator the shorted the legs together,
but that seems sort of brutal to me.

It appears to me that a simple voltage sensor and a solid state switch
is all that is needed, but perhaps I can't see the forest for the
trees as regulators, over here, cost a hundred bucks, or more.

Cheers,

Bruce

--
Best regards,
John Navas, publisher of Navas' Sailing & Racing in
the San Francisco Bay Area http://sail.navas.us/