information on Solar Panels and controllers..great site!!!-gctid371545

[Guest]

This is the best site I have found for good information on Solar Panels and controllers.

http://www.solar-facts.com/controllers/mppt-controllers.php

http://www.solar-facts.com/

I'm looking to add a set to my boat but have been cautious due to the mis-information including the wattage as opposed to the true current output (if not using an MPPT controller).

This is the best information I have found.

Larry

[TenMile]

If you want THE BEST information solar -- take a read of this site -- it's very long -- he has loads of opinions but there is ton's of great info on batteries, charge controllers, panels, wiring, placement of systems etc...: https://handybobsolar.wordpress.com/...ging-puzzle-2/

Read the details if you want -- but you can skip way down to the bottom and read the "Short Course" -- he summarizes all the details above and outlines how to properly design a system for an RV/Boat or small Cabin.

His quote on MPPT Charge Controllers for small systems like a boat or RV: If the company you are dealing with tries to tell you that you must buy the small MPPT (boosting) controller or you are wasting the watts your panels produce; walk away. Seriously, he is in the profit generating business, not the power generating business.

I've used his advice when designing solar systems for both our cabin and boat. For the cabin, I have 3x125w panels, 4xTrojan T105 Batteries (450Ah), a Morningstar Tristar-45 PWM charge controller, TriMetric 2025 Monitor and a 2000W inverter. I over-sized the cabling between the panels and CC/Batteries and designed the system for about a 2% power loss. We run lights (all CFLs), fans for the fireplace insert, TV/Satellite and a handful of small appliances and rarely see the system fall below 70% capacity over a long weekend. If the sun is out, we can get up to 100% charged before we lose sun off the panels about 3pm (trees).

I'm just doing my boat install now. From my local Craigslist I picked up 2 xT105 batteries (225Ah), an 85W panel, MorningStar 10amp CC and a 1750w inverter all for $500 (all in excellent shape). I'm just adding a TriMetric monitor (I know some users here like the Xantrex, but I'm used to the TriMetric from the cabin). Plan is to stop using shore power for the balance of the year (with the exception of the very cold months to keep a heater running in the boat), and to be able to run lights, fridge and entertainment while we are on extended holiday.

[Guest]

There is an issue using (or not using) a MPPT controller depending on the voltage output of the panel. Panels designed for power grid use usually have a 30 - 40 volt output. Without the MPPT controller you are limited to the current output of the panel. If you are using 18 - 20 volt panels it's not so much of an issue.

[TenMile]

The guy who wrote the guide above doesn't say you shouldn't use MPPT controllers, his point is that the marginal increase in performance for a small system (on an RV or Boat) isn't worth the much higher cost of these units (he recommends them for large home systems or commercial application where the performance increase justifies the higher cost).

He suggests taking the money you would spend on the MPPT controller and upgrade/oversize the wiring between the panels, controller, and battery get a PWM controller with adjustable output voltage with temperature compensation (like a Morningstar Tristar or Sunsaver) and invest in better batteries and a system monitor (he recommended the Trimetric that I purchased and it takes all of the guessing out of the equation).

On my boat, my panel is 85W (about 5A) and outputs about 18-20Vdc. I could spend an additional $300 on an MPPT controller and probably get about a 10% improvement in output power (about 500mA max) that would take the system close to it's rated performance -- or invest that $300 in beefier cabling and a monitor and minimize this loss via cabling. The Sunsaver-10 that I have on the boat doesn't have an option to adjust it's output voltage like the TriStar we have at the cabin. It outputs 14.4V where at the cabin I can adjust it higher. They do have temperature compensation built into both units which is a good thing...

[Guest]

TenMile wrote:
The guy who wrote the guide above doesn't say you shouldn't use MPPT controllers, his point is that the marginal increase in performance for a small system (on an RV or Boat) isn't worth the much higher cost of these units (he recommends them for large home systems or commercial application where the performance increase justifies the higher cost).

On my boat, my panel is 85W (about 5A) and outputs about 18-20Vdc. I could spend an additional $300 on an MPPT controller and probably get about a 10% improvement in output power (about 500mA max) that would take the system close to it's rated performance -- or invest that $300 in beefier cabling and a monitor and minimize this loss via cabling. The Sunsaver-10 that I have on the boat doesn't have an option to adjust it's output voltage like the TriStar we have at the cabin. It outputs 14.4V where at the cabin I can adjust it higher. They do have temperature compensation built into both units which is a good thing...

I don't know where he is getting his pricing but you can buy a 15A MPPT controller off ebay for less than $50. You are right that with the 18-20 volt panels it's not a big deal but it is with the 40 volt panels. If you don't use an MPPT controller on these you are limited to the straight amps out which with a 250 watt panel is around 8 amps. This is where the MPPT is an advantage.

There are some good points on wire sizing.

I'm not sure what I will finally put on the boat. I can get a 250w poly - glass panel for about $300 or two 100w flexible mono panels for $550. Advantages to both but the flexible panels are 20 volt and the poly panel which is not flexible is 40 volt.

I will definitely get a MPPT controller if I go with the glass panel.

[TenMile]

His document was written a few years ago, so I suspect as MPPT technology has matured, prices have come down a bit -- they are still over 2x the cost of PWM controllers when you look at the top brands. I wouldn't advise spending $50 on a cheap knockoff charge controller (nor would I advise purchasing cheap batteries -- it's just not a wise investment). It's such a critical component in a solar system that putting a poor one in place could waste all the investment you made in panels. I would also be concerned about the risk of fire a cheap knockoff controller can cause in a marine environment. Even if you look on eBay and check out the Morningstar controllers -- their basic Sunsaver models run about $70 for a 20A PWM or $250 for a 15A MPPT (both have temperature compensation built in). I'd get one designed for the marine environment. They really aren't that much more. You don't want to spend $500 or more on panels to have the CC as your weak link.

Morningstar itself has a good application note on PWM vs. MPPT controllers here: http://www.morningstarcorp.com/en/su...cfm?ItemId=426

A good investment for a boat is the Sunsaver Duo package: http://www.morningstarcorp.com/en/sun-saver-duo -- $145 on eBay. Includes a charge controller that can charge 2 battery banks (House and Starter). It is a 4 Stage charger (Bulk, PWM, Float and Equalize) that can extend the life of your batteries as it ensures they are fully topped up and equalized. It also comes with a full system monitor. Has me thinking I may get one of these for my boat rather than the Trimetric monitor.

I'm not familiar with these 40v panels you mention -- wonder if they are specifically for large commercial applications? Usually panels are wired for 12V or 24V. A 24V system can provide up to 40V in peak conditions -- maybe that's what you mean?

[Guest]

some hardware stores carry a few sizes of solar panels and a separate controller if you plan to power things off of them or daisy-chain them, but I was more interested in the 'maintainers' just to keep my battery charged when we've got the stereo going, etc at a sandbar for a few hours...

http://www.fleetfarm.com/catalog/category/car-truck/maintenance-parts/batteries-battery-parts/battery-doctor-1-8-watt-solar-maintainer-kit

is something like this worthwhile? for only $20, i figure it can't hurt. i know it's only producing 1.8W, which it lists as enough to keep a battery charged, which is all i'm looking for on my 175.

thoughts?

[TenMile]

Those plug in maintainers are meant to be left on you car or boat when you leave it for weeks or months and they equalize the power draw from LED lights and alarm systems. They output a max of .15 Amps. Your boat battery should store about 100-150Ah.

Your stereo with big amp and subwoofer may draw 5 amps or more per hour so that little panel (assuming no loss from cabling etc which is incorrect) will replenish about 3% of the power your stereo uses. Assuming you are at the beach for 3 hours and use 15Ah off your battery -- that panel will recharge what your stereo used after about 100 hours of sunlight. The math suggests that little panel is basically pointless. Also note that the alternator in your boat will output about 70 Amps and will likely replace all the juice you used listening to your stereo on your ride back to the dock.

You're better investing in a second battery either permanently mounted in the boat, or even one of those power packs.

[Guest]

TenMile wrote:
His document was written a few years ago, so I suspect as MPPT technology has matured, prices have come down a bit -- they are still over 2x the cost of PWM controllers when you look at the top brands. I wouldn't advise spending $50 on a cheap knockoff charge controller (nor would I advise purchasing cheap batteries -- it's just not a wise investment). It's such a critical component in a solar system that putting a poor one in place could waste all the investment you made in panels. I would also be concerned about the risk of fire a cheap knockoff controller can cause in a marine environment. Even if you look on eBay and check out the Morningstar controllers -- their basic Sunsaver models run about $70 for a 20A PWM or $250 for a 15A MPPT (both have temperature compensation built in). I'd get one designed for the marine environment. They really aren't that much more. You don't want to spend $500 or more on panels to have the CC as your weak link.

Morningstar itself has a good application note on PWM vs. MPPT controllers here: http://www.morningstarcorp.com/en/su...cfm?ItemId=426

A good investment for a boat is the Sunsaver Duo package: http://www.morningstarcorp.com/en/sun-saver-duo -- $145 on eBay. Includes a charge controller that can charge 2 battery banks (House and Starter). It is a 4 Stage charger (Bulk, PWM, Float and Equalize) that can extend the life of your batteries as it ensures they are fully topped up and equalized. It also comes with a full system monitor. Has me thinking I may get one of these for my boat rather than the Trimetric monitor.

I'm not familiar with these 40v panels you mention -- wonder if they are specifically for large commercial applications? Usually panels are wired for 12V or 24V. A 24V system can provide up to 40V in peak conditions -- maybe that's what you mean?

Yes.. I was referring to the Peak output (more accurately 34 to 38 volts). Most of the panels made in Canada are for large roof top systems and designed for adding power to the power grid (government project).

Most of the controllers are made in China anyway so the ebay stuff is a good buy if you ask enough questions. Certainly there is as always a "buyer beware" and do your home work before buying anything. I have bought a lot of electronics off ebay out of China and with the exception of a few "language issues" have not had a problem.

I have a combiner (ACR) so a single output is all I need. I may even install a switch to turn off the solar panels when at dock or under way and only use them at anchor or when I am at a dock with no power.

It's nice to get the input from people with systems now as there is a lot of mis-information about solar power out their including many of the sellers. Thanks Terry.

[Guest]

For information..I received this reply back regarding MPPT controllers from a company that manufactures solar panels and equipment.

"We suggest you use PWM charger ,beacuse the technology of MPPT is not mature enough and the effect is not very good.Please note,many thanks!

Best Regards

Cherry

- sungoldpower"

[dmcb]

lolar3288 wrote:
There is an issue using (or not using) a MPPT controller depending on the voltage output of the panel. Panels designed for power grid use usually have a 30 - 40 volt output. Without the MPPT controller you are limited to the current output of the panel. If you are using 18 - 20 volt panels it's not so much of an issue.

I know you can have a small setup like the OP is talking about without a regulator without issues. Just put an off/on switch on it so if you leave the boat for days you will not overcharge.

[Guest]

Hello,

I am considering on putting another 27 Battery under the sink w/ a 1000 watt power inverter connected to a 5 watt solar Sunforce trickle charger:

http://www.amazon.com/gp/product/B0026TBFIO/ref=ox_sc_act_title_2?ie=UTF8&m=ATVPDKIKX0DER

I do not have a generator on board and would like to use it to power a dvd/xbox as my 12volt 22" LED TV is connected to one of my bank batteries. I would use it very limited maybe 1-2 hours on the weekend while at anchor and via shore power when at the dock. Has anyone done this before w/success? Also I am considering on purchasing the 2 pack 5 watt charger from Amazon and am thinking of hooking it up to the boat via the helm cigarette plug when anchored. Will this charge my batteries? Would I have to leave the main battery switch on/off, #1/#2 battery?

Thanks,

[Guest]

Got2Cuff wrote:
Hello,

I am considering on putting another 27 Battery under the sink w/ a 1000 watt power inverter connected to a 5 watt solar Sunforce trickle charger:

http://www.amazon.com/gp/product/B0026TBFIO/ref=ox_sc_act_title_2?ie=UTF8&m=ATVPDKIKX0DER

I do not have a generator on board and would like to use it to power a dvd/xbox as my 12volt 22" LED TV is connected to one of my bank batteries. I would use it very limited maybe 1-2 hours on the weekend while at anchor and via shore power when at the dock. Has anyone done this before w/success? Also I am considering on purchasing the 2 pack 5 watt charger from Amazon and am thinking of hooking it up to the boat via the helm cigarette plug when anchored. Will this charge my batteries? Would I have to leave the main battery switch on/off, #1/#2 battery?

Thanks,

A 5 watt trickle charge (less than 1/2 amp) is basically useless in this application. You would need at least 100 watts of solar power.

You would usually use your battery switch in the house battery position leaving your other battery to start the boat.

[TenMile]

Got2Cuff wrote:
Hello,

I am considering on putting another 27 Battery under the sink w/ a 1000 watt power inverter connected to a 5 watt solar Sunforce trickle charger:

http://www.amazon.com/gp/product/B0026TBFIO/ref=ox_sc_act_title_2?ie=UTF8&m=ATVPDKIKX0DER

I do not have a generator on board and would like to use it to power a dvd/xbox as my 12volt 22" LED TV is connected to one of my bank batteries. I would use it very limited maybe 1-2 hours on the weekend while at anchor and via shore power when at the dock. Has anyone done this before w/success? Also I am considering on purchasing the 2 pack 5 watt charger from Amazon and am thinking of hooking it up to the boat via the helm cigarette plug when anchored. Will this charge my batteries? Would I have to leave the main battery switch on/off, #1/#2 battery?

Thanks,

This is really just a math problem that can be solved with a little Google searching and calculations of power you're going to use.

An XBox uses https://"http://www.planetxbox360.co...watching a DVD = ~1 amp of power draw. 1 amp at 120v =~ 12 amps DC.

So every hour you use the XBox is going to consume 12 amps (not even calculating the TV or other devices consuming power). That panel will output .5 Amps (absolute max) so for every 1 hour you watch, you'd need 24 hours of sunlight to bring the battery back up. So assuming you were away on a weekend and watched 2 movies (4 hours of use or 48 amps) you'd need 96 hours of sunlight to replenish the battery. You typically assume 6 hours of sunlight a day for budgeting so it takes about 16 days to replenish.

An 80w ~5A panel will replenish that power used in about 10 hours (~2 days).

You can get a good solar kit for a small cruiser boat for about $6-800 (a little more if you need batteries). A sample kit as follows:

- TriMetric 2025RV monitor (plus 500A shunt and cabling kit) ~$200 (provides complete detailed info on your battery State of Charge)

- Solar panel - 85-100W ~ $200

- Morningstar Sunsaver charge controller ~$50-75

- Xantrex 1000w Inverter w 20A Charger ~$150

- Batteries - pair of Trojan T105 6V 225Ah ~$300

This is a small kit, not meant to be used on a big cruiser but can be expanded by adding more panels. It's what I run on my boat. Lets you stay off the hook for extended periods and not kill your batteries, run fridge, microwave, lights and entertainment without requiring a generator. It also ensures that your batteries are always topped up and fully charged which extends their life. Also lets you run for extended periods at the dock without having to plug into shore power (in my case saves me ~$20-30/mo) for 75% of the year.

Of the parts above -- IMHO the meter is mandatory (otherwise you're always guessing/worried about the charge state of your batteries). The TriMetric measures both Watts/Amps generated and consumed simultaneously so will accurately tell you exactly where you're at. Charge controller is also mandatory or you risk over-charging your batteries and boiling them dry. The size of panels, batteries and inverter is all based upon your intended use and consumption.

Just came back this weekend from opening the family cabin where we have a kit almost identical to the one above just larger (375w of panels, a 2000w inverter and charge controller and 4 of the batteries). It runs Satellite TV, Lights, and small appliances plus the vacuum for 4-6 adults and 4 kids and we rarely see the batteries fall below 80% SOC overnight and it's typically 100% charged by the time the sun is off the panels. System is into it's second season and I'm pleased to stay that we've never had to run the generator to charge the batteries. Batteries are always fully charged and the cabin is lived in full time from June to Sept -- checked the water levels and the batteries were perfect. It's a very low maintenance system.

[Guest]

I just ordered two 100 watt semi-flexible solar panels and a 20 amp PWM controller. Cost was $550 US. When I get it installed in a month or so I will report the actual performance back to BOC. I went with the PWM controller because the max voltage output of these panels is under 20 volts so you will not get much out of a MPPT controller. Also the panel manufacture did not recommend using a MPPT controller because they feel the technology is new and the units in their experience are not as reliable. They also have seen 10% max improvement over a PWN, not the 30% that is claimed by some controller makers.