use of "plug and play" solar for temporary use

[BOAT]

Yup, Be Free the free man is right on all counts except the pi$$ and vinegar - that one was not me - that was Tom.

His approach makes the most sense too - in fact I would say he has better advice than I because he knows how to get the components for less money. I am no expert on component specs so I end up buying the most expensive stuff. If you use the Free Mans advice you can save money.

So, "Be Free"!

[Herschel]

Get the frig, see what it does to my system power wise and go from there. Get the battery monitor and shunt so I can see what really is happening. Progress. Thought I was about to graduate from this online engineering school, but then: "I'll probably go with solar and a purpose built frame and an MPPT controller when I get around to that particular project. That's what my calculations say works best for me. YMMV." What is MPPT and YMMV?

[Tomfoolery]

What is MPPT and YMMV?

See page 1, and Your Mileage May Vary.

Big Caveat: You have to use a charge controller specifically designed for the battery chemistry you're charging. Lithiums charge differently, and at different voltages, than lead acid which is different from AGM and so on. And there are different types of charge controllers, for that matter, with PWM types being cheapest (Pulse Width Modulated, which means it's simply switching on and off rapidly to control effective voltage), and MPPT (Maximum Power Point Tracking) types, which adjusts both voltage and current to best match the solar panel output to the battery charging requirements, and adjusts itself as clouds go by and things like that. They're the best controller type, but probably unnecessary for a single 100W panel, and far more expensive than simple PWM types.

[BOAT]

Yeah, what he said - they both do the same thing a different way. Either is good. For a small solar system PWM is okay - if you do a large system with many panels and a lot of power (like I have on my van) then MPPT is a little better at dealing with the shade of trees over one panel in series with another panel and the whole thing gets really complicated (another rabbit hole) . . . .

Really, on 'boat' I just throw a 60 watt portable solar panel on the sliding hatch and plug it into the cig lighter if I am on the hook for more than a day. That's plenty because I still use a Polar Bear.

If I had a reefer on boat? Well, again - it's the battery issue. Changing my batteries to Lithium is a huge project because everything else has to change too (charger, controllers, blah blah) so for now if I were going to get a reefer I would probably be asking myself:
- "why am I getting a reefer when the Polar Bear will keep ice for four days?"

I guess I will sit down a design a reefer/solar system for the M boat this winter and list the parts here and get Free Man to help me choose bargain components. When I do that you can copy that system. Really, just like Be Free, I am not to keen on hard panels on a boat - windage is just too crazy.

[Herschel]

Great guys. I was watching some YouTube channels on solar tonight. Pacific Yacht Services, for example.
https://www.bing.com/videos/search?q=yo ... &FORM=VIRE
It really is something you have do right. Like 100%. One small detail he emphasizes in the installation of solar systems is the need for a fuse near the positive terminal of your battery. Then he casually mentions not to plug your solar wires from a portable unit into each other for storage with the panels exposed to sun light or you will fry your panels. There seems to be a ton of ways to do something stupid for a first time DIY guy. It has me thinking that I might want to break into solar with a power station after all and just get my feet wet before I tackle a permanent install on my boat. Back to equivocating again. You learn something that gives you a little confidence, and then you learn something that is a mite scary. But, then as good old Robert Frost said so eloquently,

Two roads diverged in a yellow wood,
And sorry I could not travel both
And be one traveler, long I stood
And looked down one as far as I could
To where it bent in the undergrowth;

Then took the other, as just as fair,
And having perhaps the better claim
Because it was grassy and wanted wear,
Though as for that the passing there
Had worn them really about the same,

And both that morning equally lay
In leaves no step had trodden black.
Oh, I kept the first for another day!
Yet knowing how way leads on to way
I doubted if I should ever come back.

I shall be telling this with a sigh
Somewhere ages and ages hence:
Two roads diverged in a wood, and I,
I took the one less traveled by,
And that has made all the difference.

[Dimitri-2000X-Tampa]

I have a 100w flex panel that I use on multiple boats, a little controller and some alligator clips to the battery. One of these days I'll get an electric fridge cooler most likely..maybe I'll need 200w for that. Here is a pic of it strapped to my Bimini on M26X for last year's BEER cruise ...keeps my batteries charged when I'm not motoring or at a marina.

And here is the same panel being used AS the Bimini on my CS17mk3

Which has no other way to charge the battery.

[Herschel]

I have a 100w flex panel that I use on multiple boats, a little controller and some alligator clips to the battery. One of these days I'll get an electric fridge cooler most likely..maybe I'll need 200w for that. Here is a pic of it strapped to my Bimini on M26X for last year's BEER cruise ...keeps my batteries charged when I'm not motoring or at a marina.

And here is the same panel being used AS the Bimini on my CS17mk3

Which has no other way to charge the battery.

Do you clip it to your house battery or starter battery or which ever one needs it? Does the controller have any digital readout for the battery monitor capability?

[Dimitri-2000X-Tampa]

I have the big red A/B battery switch so I can use that to charge either or both batteries. I have one group24 starting battery and a group29 house battery. The controller is one of these cheapos from China which has USB ports and a display that shows if the panels are providing power to the battery and it shows the voltage and doesn't let it go above about 14.4 I think. Like this one:

https://www.ebay.com/itm/30A-Solar-Pane ... 0012.m1985

[Herschel]

I have the big red A/B battery switch so I can use that to charge either or both batteries. I have one group24 starting battery and a group29 house battery. The controller is one of these cheapos from China which has USB ports and a display that shows if the panels are providing power to the battery and it shows the voltage and doesn't let it go above about 14.4 I think. Like this one:

https://www.ebay.com/itm/30A-Solar-Pane ... 0012.m1985

So, you attach the alligator clips to the red A/B/Both battery switch and just dial in the battery you want to charge? Do you ever do it in the "both" position?

[Dimitri-2000X-Tampa]

So, you attach the alligator clips to the red A/B/Both battery switch and just dial in the battery you want to charge? Do you ever do it in the "both" position?

Not quite, I just attach the alligator clips to one of the batteries (easiest on the posts) and if I want to charge the other one that is not connected to the clips, that's when I use the 'both' position which puts both batteries in parallel. I think the way current works is that the smaller battery charges first in the both position. I use the same tactic with my portable electric battery charger which sits next to the batteries. Its kind of rusty after 15 years or so, but it still works...so, I use portable connections for all charging. I know there is much better quality equipment for both the controller and the battery charger but when the stuff is so cheap, I don't really care if it stops working and I have to buy another one because I could probably do that 10 times before paying as much for the fancy (marine grade) equipment. Now for other things (like fasteners, etc) that are going to be in the elements, I'm going to be using marine grade SS and that sort of thing.

[Herschel]

Just to be clear. If I install, or have installed, this battery monitor:
Which advertises as follows:

Battery "fuel-gauge", time-to-go indicator, and much more - The remaining battery capacity depends on the ampere-hours consumed, discharge current, temperature and the age of the battery. Complex software algorithms are needed to take all these variables into account. Next to the basic display options, such as voltage, current and ampere-hours consumed, the BMV-700 series also displays the state of charge, time to go, and power consumption in Watts. The BMV-712 features an additional input which can be programmed to measure the voltage (of a second battery), battery temperature or midpoint voltage.

I would set the shunt on the negative terminal of the house battery since that is the one that I am depending on to run my frig and other 12 volt equipment when not plugged into shore power or running my engine. The battery monitor will give me all the info I can possibly use about the house battery and the 12 volt gear it runs. But, with since "The BMV-712 features an additional input which can be programmed to measure the voltage (of a second battery), battery temperature or midpoint voltage.", I can use it to monitor my starting battery as well. Can somebody say, "Yes, Herschel, you nailed it!"?

[Be Free]

It will monitor the voltage of your start battery. If you have a dedicated start battery that should be enough. It starts the engine and then gets charged back up while the engine is running (just like your car).

[Herschel]

It will monitor the voltage of your start battery. If you have a dedicated start battery that should be enough. It starts the engine and then gets charged back up while the engine is running (just like your car).

Roger that. The second lead will just measure the voltage on the starter battery. The full analysis (amps available, percent discharge, draw from various pieces of equipment) will be for the house battery and associated equipment.

[Be Free]

"Yes, Herschel, you nailed it!"

[Herschel]

"Yes, Herschel, you nailed it!"

God bless you! I'll grab my Mac 26 marine electrical "GED" and skedaddle...