Is anyone familiar with "self regulating solar panels"? I would like to
hear from someone who has installed one without a regulator and how
well it keeps the batteries up.

Thanks,
Gary

Gary wrote in news:uVSyg.273940$IK3.20678
@pd7tw1no:

Is anyone familiar with "self regulating solar panels"? I would like
to
hear from someone who has installed one without a regulator and how
well it keeps the batteries up.

Thanks,
Gary



As long as the AH created by the solar panels is LESS than the AH needed
to keep the batteries charged up full, you don't need a regulator. Ours
puts out 5 A in bright sunshine, hardly a battery buster to two banks of
L16H beasts who simply digest it and feed it to the pumps and lights...
(c;

The solar panels aren't "self regulating", per se. Their open circuit
voltage is around 18V in bright sunshine. Their internal resistance,
which makes the cells get hot when charging the batteries, drops the
difference between 18V and what voltage the batteries are producing at
the time, like 13V. 5V X 5A = 25W across the whole panel. You'll notice
old panels that have been powering stuff for a few years turn brown on
the part of the silicon that's producing the power because of the heat.
Around the edge, they're still blue like new where it doesn't produce
power. Silicon melts at a very high temperature, but you can damage the
cells by causing migration of the doping across them if they get too hot.
If any cell isn't in the sunshine, like a shadow from the
boom/mast/rigging, output drops like a rock as that cells voltage, around
..3V to .6V depending on the sun, is lost. The stupid idiots who run
South Carolina DOT put up solar power panels along the interstate to
power the radars and traffic cams. Of course, true to their idiotic
thought, they put the panels on the NORTH SIDE of the pole the radar/cams
are on so the panel has a shadow that moves across it all day. Dumb,
very dumb.

Gary wrote in news:uVSyg.273940$IK3.20678@pd7tw1no:

Is anyone familiar with "self regulating solar panels"? I would like to
hear from someone who has installed one without a regulator and how
well it keeps the batteries up.

Thanks,
Gary

I've never heard of a self-regulating solar panel, but I would suggest that
you need one. The problem occurs when your boat is plugged into shore power
and the batteies are fully charged. If there's nothing drawing any current,
then the additional amperage will easily bring your batteries way above
charging voltage

What you need is a regulator that runs in diverter mode. In this mode it
senses the voltage and when it goes above the level that you've set, it
diverts some of the wattage to a resistive load (in my case, a water heater
element in my hot water tank). There is absolutely no loss when running in
this mode. This regulator controlls both my solar panels and my wind
generator.

I would suggest looking at charge controllers from MorningStar. I went
through several Trace/Xantrex and finally scrapped it. It seems that once
they started buulding the units in China that the reliability went to hell.
I went with MorningStar TriStar unit and have been very happy with it.

-- Geoff

"Geoff Schultz" wrote

What you need is a regulator that runs in diverter mode. In this mode it
senses the voltage and when it goes above the level that you've set, it
diverts some of the wattage to a resistive load (in my case, a water
heater
element in my hot water tank). There is absolutely no loss when running
in
this mode. This regulator controlls both my solar panels and my wind
generator.

I would suggest looking at charge controllers from MorningStar. I went
through several Trace/Xantrex and finally scrapped it. It seems that once
they started buulding the units in China that the reliability went to
hell.
I went with MorningStar TriStar unit and have been very happy with it.

Geoff,

I have been looking at the Tristar but couldn't figure out what to divert
to. How did you wire up the water heater to isolate the Tristar from the AC
shore power?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Glenn Ashmore" wrote:


"Geoff Schultz" wrote

What you need is a regulator that runs in diverter mode. In this mode it
senses the voltage and when it goes above the level that you've set, it
diverts some of the wattage to a resistive load (in my case, a water
heater
element in my hot water tank). There is absolutely no loss when running
in
this mode. This regulator controlls both my solar panels and my wind
generator.

I would suggest looking at charge controllers from MorningStar. I went
through several Trace/Xantrex and finally scrapped it. It seems that once
they started buulding the units in China that the reliability went to
hell.
I went with MorningStar TriStar unit and have been very happy with it.

Geoff,

I have been looking at the Tristar but couldn't figure out what to divert
to. How did you wire up the water heater to isolate the Tristar from the AC
shore power?

We divert the excess solar power (and wind power) to little fans that
run in the cabins and keep the air circulating. We can tell when the
batteries are charged if the fans start to run. If the boat is on the
hard and we aren't aboard, it helps to have the air circulate. YMMV

"Glenn Ashmore" wrote

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


I like the idea of diverting to the water heater, but most of us do not have
the option to add a second 12V element to our existing heaters.

One thought, would be to add a second heater in an external loop around the
water heater - something like the add-on heaters that are sold for cars in
lieu of a block heater. This site has the elements:

http://www.realgoods.com/renew/shop/...204/ts/1025078

But, if the solar panels put out, say 150 watts for 8 hours, what happens
when the water becomes too hot? With a small boat type water heater say 6 or
10 gal, this could happen quite quickly. Maybe then we throw the towel?

GBM

"GBM" wrote in
:


"Glenn Ashmore" wrote

I'm building a 45' cutter in strip/composite. Watch my progress (or
lack there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


I like the idea of diverting to the water heater, but most of us do not
have the option to add a second 12V element to our existing heaters.

One thought, would be to add a second heater in an external loop around
the water heater - something like the add-on heaters that are sold for
cars in lieu of a block heater. This site has the elements:

http://www.realgoods.com/renew/shop/...1204/ts/102507
8

But, if the solar panels put out, say 150 watts for 8 hours, what
happens when the water becomes too hot? With a small boat type water
heater say 6 or 10 gal, this could happen quite quickly. Maybe then we
throw the towel?

GBM

You can get elements that have both 120V AC and 12V DC feeds. See
http://www.svhotwire.com/divert_loads.html

-- Geoff

I used diverted power from my solar regulator to run fans throughout the
boat.


"Geoff Schultz" wrote in message
6...
"GBM" wrote in
:


"Glenn Ashmore" wrote

I'm building a 45' cutter in strip/composite. Watch my progress (or
lack there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


I like the idea of diverting to the water heater, but most of us do not
have the option to add a second 12V element to our existing heaters.

One thought, would be to add a second heater in an external loop around
the water heater - something like the add-on heaters that are sold for
cars in lieu of a block heater. This site has the elements:

http://www.realgoods.com/renew/shop/...1204/ts/102507
8

But, if the solar panels put out, say 150 watts for 8 hours, what
happens when the water becomes too hot? With a small boat type water
heater say 6 or 10 gal, this could happen quite quickly. Maybe then we
throw the towel?

GBM

You can get elements that have both 120V AC and 12V DC feeds. See
http://www.svhotwire.com/divert_loads.html

-- Geoff

"Geoff Schultz" wrote

You can get elements that have both 120V AC and 12V DC feeds. See
http://www.svhotwire.com/divert_loads.html


That's great, but:
- how is the water temperature controlled? Temperature should not exceed
49C to prevent scalding (used to be 60C)
- Once water reaches maximum temperature, what do you do then?

Seems to be of limited value if engine is also used to heat water. Our hot
water gets up to about 45C after an hour of motoring at low speed. It is
self limiting because of engine thermostat.

GBM

In article ,
says...

"Glenn Ashmore" wrote

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


I like the idea of diverting to the water heater, but most of us do not have
the option to add a second 12V element to our existing heaters.

One thought, would be to add a second heater in an external loop around the
water heater - something like the add-on heaters that are sold for cars in
lieu of a block heater. This site has the elements:

http://www.realgoods.com/renew/shop/...204/ts/1025078

But, if the solar panels put out, say 150 watts for 8 hours, what happens
when the water becomes too hot? With a small boat type water heater say 6 or
10 gal, this could happen quite quickly. Maybe then we throw the towel?

According to this handy calculator:

http://chuck-wright.com/calculators/watts.html

Heating 6 gallons of water by 100F will require about 240 Watts
for 6 hours. You're not likely to boil the water in in
the heater with that amount of input. With losses, 6 hours
at 150Watts is probably just enough for a hot shower. OTOH,
on a day sunny enough to give you 150 Watts for 6 hours,
you probably don't need a HOT shower. ;-)

Mark Borgerson