Solar panels

druid · Sep 1, 2016

Brian S said:
Not true!

In this article, MaineSail shows how a 12W panel brought a 220Ah bank of batteries to 15 volts. http://www.pbase.com/mainecruising/do_i_need_a_controller

Charge controllers are probably less expensive than replacing batteries all the time.

Yeah... I guess if you have it hooked up ALL THE TIME and don't have any load. When I used my 45W panel, I just hooked it to the battery when I was using it. I just put it where the sun was, adjusting as the day went on. When not in use, I disconnected it and put it away. If you use it this way, you don't need a controller.

druid

Sailm8 · Sep 1, 2016

SFS said:
@Sailm8 Do you have the specs, or a link to the product?

I think this was the company. It's been a while since I bought them: https://www.amazon.com/HQST-Monocry...72775485&sr=8-2&keywords=flexible+solar+panel
They are like seconds and you need to check them out to make sure they put out up to specs but mine did right out of the box. Used Amazon Primes so I could sent them back if they were out of spec. Bought a vectron (sp) MPPT controller to go with them. I mounted them on the bimini with zip ties. Currently holding up just fine to Tropical Storm Hermine.

All U Get · Sep 2, 2016

That far north you might want to tilt those panels to maximize any sun. I have a 50w panel on my backhoe with a little controller to protect from an overcharge. Works slick even with 6" of snow on top.

All U Get

RussC · Sep 5, 2016

Mounted mine off the rear by using a curved 1" aluminum tube clamped to the upright. gets it totally out of the cockpit and out of the way. controller is in the cabin. takes minor fabrication work, but all easy stuff. The curved tube was stolen from a dead sears weedwhacker

.
You don't plan on installing all three panels do you? what do you plan to run with them? My 40W has proven to be more than enough for multi day trips powering stereo cd player, Garmin sonar, lights, etc.

Charlie Jones s/v Tehani · Sep 5, 2016

RussC said:
My 40W has proven to be more than enough for multi day trips powering stereo cd player, Garmin sonar, lights, etc.
View attachment 127758 View attachment 127759

Lived aboard and cruised full time for 2 1/2 years using a single 32 watt panel,, and a single battery. In that time,, had to go in and plug in a battery charger twice, due to prolonged very cloudy weather. Charged laptops and phones with no trouble.

Of course, I am VERY frugal with my electricity

SwitchintoglideIII · Sep 7, 2016

Three 7 watt solar panels...2 aft (for 2 house 27N deep cycles)....& 1 forward (with a smaller 24 for the bow thruster)
Both set ups have charge controllers, and never need charging otherwise

Bill and Kathy McDonald · Oct 24, 2016

Really late to the party, but here is the homemade mount for our solar panel over the transom.

IMG_3415

Bill and Kathy McDonald
Oct 24, 2016

. Being kept in the water with no electrical access, it's perfect for charging the battery. We keep the mast light on 24/7 to comply with the rules.

Ned Ludd · Oct 24, 2016

On My Neptune 24 I mounted a mast on the stern opposite the outboard motor. The 55 watt panel was 6'6" off the deck when horizontal so it was not a head knocker and it also protected it from flying beer bottles on tacks. When docked or anchored I would tilt it to the sun.

NotCook · Oct 24, 2016

All U Get said:
I have a 50w panel on my backhoe with a little controller to protect from an overcharge.

Your boat has a BACKHOE? That's awesome! Bet that comes in handy for digging clams! I wanted a davit (crane type) on the main deck behind the boom, but my builder said we would probably have to reinforce the steel deck...

cbourne200 · Oct 25, 2016

I have a 25W panel, controller, 2 type 31 Duracell deep cycle batteries. Started using battery 1 to start westerbeke diesel one time, battery 2 next time. Went out yesterday & tried using battery 1. Wouldn't start. Changed to both battery & started fine. Batts are 1 yr old. What should I have controller set on for trickle charge? Was prev set for 13.7. I bumped it up to 14.2. Has been 2 weeks since motor started. No drain on batts, only use to start motor and occasional depth gauge. Battery selector always turned to off before leaving boat.

Chief RA · Oct 25, 2016

Much misinformation on this site relating to solar panels. If controllers are needed on such small panels as is stated here we would be using controllers on 115AC trickle chargers! Chief

Stu Jackson · Oct 25, 2016

cbourne200 said:
Wouldn't start.

Are you sure it's the battery? Did the engine turn over, or just nothing?

Brian S · Oct 25, 2016

Chief RA said:
Much misinformation on this site relating to solar panels. If controllers are needed on such small panels as is stated here we would be using controllers on 115AC trickle chargers! Chief

MaineSail has seen small panels that supposedly did not need a controller bring a battery beyond charged and ruin it. Admittedly, this happened over the course of a whole winter or something, but still...

Maine Sail · Oct 26, 2016

Chief RA said:
Much misinformation on this site relating to solar panels. If controllers are needed on such small panels as is stated here we would be using controllers on 115AC trickle chargers! Chief

Most "trickle chargers" have built in regulation circuitry. For constant current "trickle chargers", of which there are very, very few today, most battery makers will void warranty if you use them. They all recommend CC-CV charging.

I have seen numerous banks destroyed by unregulated solar, even with very small panels compared to bank size...

Chief RA · Oct 26, 2016

Cheap trickle chargers still are not regulated, and many people use them with no problem. Their "regulation" is the DC potential they produce which is barely above or at full battery DC charge. The concepts regarding small solar panels are much misconstrued with regard to use of regulators! If the batteries are fully charged the voltage difference due to load effect between a small panel and bank is so small that there is minimal current, cool batteries. The best approach to this is to not leave them unattended for extended times no matter what system you use. MS, your advice to fully charge and leave them off the circuit in the winter or when not attended is best and is what I do for winter. Chief

Chief RA · Oct 26, 2016

Brian S: Electronic theory indicates that the small panels could not cause such problems and so likely the batteries, wiring, etc. were questionable, or some other reason if the batteries failed . My education tells me, if current level does not EVER exceed 2% or less of the total battery ampere hour rating the wattage conversion to heat is insufficient to cause such malfunctions. Of course the solar industry would like for everyone to think they need a controller and sell them one. I do think greater caution is in order for boats. Chief

Maine Sail · Oct 26, 2016

Chief RA said:
Cheap trickle chargers still are not regulated, and many people use them with no problem. Their "regulation" is the DC potential they produce which is barely above or at full battery DC charge. The concepts regarding small solar panels are much misconstrued with regard to use of regulators! If the batteries are fully charged the voltage difference due to load effect between a small panel and bank is so small that there is minimal current, cool batteries. The best approach to this is to not leave them unattended for extended times no matter what system you use. MS, your advice to fully charge and leave them off the circuit in the winter or when not attended is best and is what I do for winter. Chief

Chief,

The terms "Trickle" and "Maintainer" have become abused and diluted definitions. Historically "trickle" meant a trickle of constant-current with no voltage regulation. Charger makers have smartened up a LOT over the years, probably driven by lawyers, and tickle charging is almost non-existent today except for perhaps a few bottom feeding Chinese products.

There is not a battery maker out there who does not require a CC-CV (constant current to constant voltage) charge regimen

I don't know how "cheap" you are going but even the Harbor Freight "trickle chargers" or "maintenance chargers" are float voltage regulated.

The Battery Tender is float voltage regulated.
The BatteryMINDer is float voltage regulated.
The Schumacher "trickle charger" is float voltage regulated.
The CTEK's are float voltage regulated
The Black & Decker trickle/maintainers are float voltage regulated.
The NOCO is voltage regulated On/Off (pulse) charging
Etc. etc.

Even battery manufacturers such as Lifeline weigh in on "constant-current "trickle" charging:

"Trickle Charging
Method of charging in which the battery is either continuously or intermittently connected to a constant current charging source to maintain the battery in a fully charged condition. Not recommended for use with Lifeline® AGM batteries."

FWIW this is a 400Ah bank that requires just 00.1A to not exceed 14.4V once the battery is "fully charged". This battery should be "floating" at 13.5V not being held at a CV of 14.4V. Even a diminutive 1.0A constant current trickle charger will easily push this bank beyond 15.0V..

Maine Sail · Oct 26, 2016

Chief RA said:
Brian S: Electronic theory indicates that the small panels could not cause such problems and so likely the batteries, wiring, etc. were questionable, or some other reason if the batteries failed . My education tells me, if current level does not EVER exceed 2% or less of the total battery ampere hour rating the wattage conversion to heat is insufficient to cause such malfunctions. Of course the solar industry would like for everyone to think they need a controller and sell them one. I do think greater caution is in order for boats. Chief

Chief,

Sorry but you are incorrect on this.. Do your self a favor and please watch the videos and read the below article.

2% of Ah capacity in constant current will FRY your batteries. This 2% as "full" BS started with Ah counter manufacturers needing a % of Ah capacity "figure" to re-set an Ah counter to 100% SOC. It does NOT mean the battery can continually continue taking 2% of Ah capacity. Most batteries are not full, meaning they will not deliver 100% of Ah capacity, until the current has fallen to 0.3 -0.7% of Ah capacity. If you hold constant voltage at absorption, beyond this point, and do not drop to a float CV, you are now over charging your batteries. If you hold constant-current, with no voltage regulation, you will destroy them even faster.
http://www.pbase.com/mainecruising/do_i_need_a_controller
Do I Need a Solar Controller (LINK)