Solar Panels

YYZRC

Looking for thoughts on a solar panel that would help keep my house bank powering the fridges. Will use genny as needed for bigger stuff. I would be mounting on the arch. 

Thanks!

aero3113

Interested 

PickleRick

I use a single 50 watt and controller on my sailboat.  Keeps 2 group 31s topped off.  Can run fans, radio with 2 speakers, 2 small fans and lights all weekend before going below 11 volts.  

I have less than 250 in the set up.  Ebay solar panel and controller. 

Solar is my only charging in the sailboat.  The motor runs off a dedicated battery.

PickleRick

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I run a near identical panel.  Used on 2 different sailboats and have another for the 2859 im going to get.

PickleRick

https://www.googleadservices.com/pagead/aclk?sa=L&ai=DChcSEwi74IqMiK_qAhUVjcgKHX30BaQYABAGGgJxdQ&ae=1&ohost=www.google.com&cid=CAESQOD2oExHFOPcwK7N8fXZI0Gr3cEawcTwwq700TZqjTjF6vjC1D_PW5M-DNANNum4Azhy257C3PMCcW2yMjcmjgU&sig=AOD64_14fEdeLk_C3IFbm0wKtzD0BmwtNg&ctype=5&q=&ved=2ahUKEwjTkP-LiK_qAhWETN8KHVjaBWoQwg96BAgMEBQ&adurl=https://www.homedepot.com/p/Renogy-12-Volt-24-Volt-10-Amp-Wanderer-PWM-Common-Positive-Solar-Charge-Controller-with-LCD-Display-CTRL-WNDPG10/310544377?mtc=Shopping-VF-F_D27E-G-D27E-27_31_CONTROL-MULTI-NA-Feed-PLA-NA-NA-CONTROL_OtherControl&cm_mmc=Shopping-VF-F_D27E-G-D27E-27_31_CONTROL-MULTI-NA-Feed-PLA-NA-NA-CONTROL_OtherControl-71700000053528212-58700005127833923-92700048704113435&gclsrc=aw.ds&&gclid=CjwKCAjwi_b3BRAGEiwAemPNU67Lat3sWOFrIN34Aan9bdZJ2-UCLeo5x2OzeqNg0GF39zpyW7kX7xoC-bwQAvD_BwE

Controller i use to monitor the panel, keep it from discharging batteries when dark and prevent over charging.

Dream_Inn

If you are going down to 11V, you have killed your batteries.  Actually, if you go below 12V more than a few times, you've at least damaged them.

PickleRick

These are deep cell house batteries.  They dont mind being run down low.  Think trolling motor or gold cart batteries.  These are not starting type batteries.  You dont want to store them discharged.  The solar panel tops them off for you.

Typically you'll get 150 or more cycles from the battery bank using 20 to 50% of your powers capacity.  

Don't do this with starting batteries 

andyd

I haven't plugged into shore power in years. I use a 100w Renogy solar panel from Amazon mounted on the arch to keep the house battery powered and have a small 10w panel to keep the other battery charged. I only run the frig for enough time to chill beers in the freezer compartment, usually 30 minutes is enough. The panel keeps up with all other demand. I never run the A/C. Both batteries are dual purpose AGM's from West Marine made by DEKA.

Andy

PickleRick

Shore power is for chumps. The only way ill get shore power is if i steal it.  Not uncommon in my area of the lake, there were vagrants burying power cords through the woods stealing power from a state park not far from where i launch.  

YYZRC

What about something like this?  Thinking I would install on the bimini rather than futzing around with the limited space on the arch.

https://www.amazon.com/Giosolar-Flexible-Monocrystalline-Photovoltaic-Controller/dp/B0859DD6DR/ref=sr_1_3?dchild=1&keywords=giosolar&qid=1593830623&sr=8-3

212rowboat

i'll share this:  i had 2 group 31 AMG batteries that i used for running auxiliary items exclusively- from a eberspacher diesel fired furnace to a heater core fan; from a winch to an air-compressor... i put a 100 watt solar panel and controller (built together) on top of the cab (was the bed of a truck) built into the rack i had, and was expecting it just to 'tend' the battery.... uh... it more than tended, it kept both those batteries FULL- and i used them quite regularly... 

i highly recommend solar panels for this application... newer tech solar panels (which aren't as easy to find as you'd think as the chinese want to sell all their early generations stock piled before they flood the market with the good ones) are flat out amazing... 

 

YYZRC

Awesome, thank you for your input! How can one differentiate the the high efficiency panels from the lower efficiency panels?

212rowboat

the panel in the picture is 'old tech'- and the one i spoke of keeping those two 31g AMG's topped.. i should have made that more clear... it was 100w and didn't 'tend' those batteries, it flat out charged them. 

the 'new' tech experience i had was with military equipment- i don't know that they're something that is commercial off the shelf except for those who really REALLY want them they are so cost prohibitive.. the rumor is it's all about dumping the old tech before launching, full scale, with the better ones- or- charging a stupid amount for the new tech to cover the cost of getting rid of the old stuff...... you can't (or aren't supposed to) just toss a panel in the garbage... they start fires or electrocute people... 

the new tech seems almost (to me) to have a surface on it like the old polaroid film did... not as squishy/pronounced, but something like it. 

@Alswagg - tricky question... IF your guy uses a domed or 'pliable' panel that gets good exposure for, say, 6 hours- it would keep topped (tend) the batteries with 50~100w pretty easy... that's considering it's producing perhaps a third of the wattage for 2/3 of the time, and full wattage for a third of the time... if you had a 150w~200w panel that only got good exposure for an hour or maybe two due to placement? not as good... 

you 'can' choose panels that 'overcharge'--- they have an additional cell that provides more voltage... like cramming 24v through a bulb rated for 12v... bulb won't last as long- like, maybe 10% as long- but for the amount of time it does? that rascal will be bright... so if on a flat surface and with only a short(ish) amount of time to charge- a 24v or 28v panel stepped down with either a potentiometer or a diode to 16v will flat out rush that (those) batteries with charge and perhaps charge it just as much as the panel with 6 hours exposure... be mindful what 'kinds' of batteries you're charging like this, though... some may not appreciate it, and that 'overcharged' light bulb at the end of it's life comes back to mind.... you can certainly touch 15vdc safely with most batteries... and get a good 'charge' not just a tend.... 

i stepped that one in the image to 16v i think it was... and ended up dialing it back to around 14.5v... i got/get plenty of exposure where i am (geographically).  

212rowboat

yeah 50w, without a draw, will most likely do it, though i didn't ask you the capacity or do the math to support it.. my gut tells me that is sufficient to tend. i'd select one with an adjustable controller and meter the voltage to not exceed 15.5vdc... you can actually use as small as 14ga wire on this from within 20' or so- it's not like a massive amount of juice is flowing through the wire, which is why i like them so much... you can find a place where the exposure and convenience (as in 'not in the way') is good as a primary concern, and then worry about how you're going to wire them in... and don't get real hung up on the adjustable controller thing, either... if they are marketed as 'battery chargers' (most if not all are), then they're already playing voltage games to maximize their appeal...  

some controllers are smart and actually sense when all the cells are producing, and what they're connected to- and throw everything they can at the batteries WHEN they can, and shut off when they could be a liability... 

start poking around them a bit and you'll find precisely what you're needing... 

there is a guy living near me who took the top off his 36v golf cart and formed a solar panel to it- you can hardly tell it's there- ran wires down the 1" tube stock of the tops frame, through the fiberglass body and to his battery's main block... stepped a 72v array to 44vdc, and keeps his cart fully charged rarely plugging it in.  wanna guess where i got most my intel about these things from? heheheheeeee

YYZRC

I'm still interested in doing this.  I found a local company that has reasonable prices.  I think I will start with 220w as the two panels will easily fit on the bimini.

https://marinesolar.com/sunpower-semi-flex-kits