Need Help setting up a Small Solar system.

[Travelover]

where I am sometimes I get cloudy days with light rain for a full week!. if that's ok with the OP, then fine..

If he was steadily using up the batteries, that would matter, but all he wants is to keep them from self discharging to the point where they are damaged or the equipment won't start.

 

[Jstpssng]

I really did appreciate the other way of looking at things James added. That one never occurred to me.

That was what I thought he was talking about when I read the heading.

 

[radios1]

That was what I thought he was talking about when I read the heading.

Me too!. "Solar Electric System" would be more accurate..

 

[newbury]

That was what I thought he was talking about when I read the heading.

That was my take on the title, and then I thought he was going to need a big tractor to pull planets into orbit. I'd start by closely reading Hitchhiker's Guide to the Galaxy.
This thread could get longer than removing a drain plug or pallets.

 

[mikester]

The best cure for the free solar power generation bug is to go buy a cheap $20 solar trickle charger and install it on one of your tractors.

After you discover you killed your $100-$200 tractor battery reverse powering your cheapo solar cell, you wont be tempted to cheap out on your $5000-$10,000 solar charging system that requires regular maintenance if you want the batteries to last more than 5 years.

That wall receptacle powered by the utility starts looking better and better!

 

[k0ua]

That was my take on the title, and then I thought he was going to need a big tractor to pull planets into orbit. I'd start by closely reading Hitchhiker's Guide to the Galaxy.
This thread could get longer than removing a drain plug or pallets.

It is doing all the math to figure out the orbits that is the problem.

 

[4570Man]

I can’t think of any reason a battery tender need to work continuously. If it doesn’t get any power at night and rainy days that should be alright. Can’t you just wire the solar panel directly to a 12 volt battery tender with some sort of anti back feed in between them?

 

[TnAndy]

The best cure for the free solar power generation bug is to go buy a cheap $20 solar trickle charger and install it on one of your tractors.

After you discover you killed your $100-$200 tractor battery reverse powering your cheapo solar cell, you wont be tempted to cheap out on your $5000-$10,000 solar charging system that requires regular maintenance if you want the batteries to last more than 5 years.

That wall receptacle powered by the utility starts looking better and better!

While true power flows from higher voltage to lower voltage, and thus power from a battery has the potential to flow backwards at night in a "cheap $20 solar trickle charger" (you get what you pay for) unless you also install a blocking diode, you also don't have to go $5000 to set up what the OP wants.

Using any charge controller will do the trick, as they don't allow backflow.

Here is a simple setup I use on my sawmill battery to keep it charged. I started to have power at the building at one time (reason for the meter base/etc), then decided I really didn't need it, nor the $40/mo minimum bill for having a meter there, so I later did this solar charging system to keep the battery topped off. About 100 bucks in the setup, been working fine for many years.

40w panel, south facing:

Wire from the panel to the 10amp charge controller. 3 red LED lights mean fully charged battery.

Wire from the controller to a plug I disconnect when the mill is running (saw with battery moves, can't stay connected)

Then another small setup we have is for an automatic chicken door that uses a 12v motor twice/day. The coop is something temporary we use to raise new layers to get big enough until they can be integrated with the existing flock, so I don't have 120vAC power to it, nor does it stay in the same place each time we use it....so an independent solar power system works best for it.

50watt panel on the roof:

Charge controller, battery, 12v timer to operate the door, wiring mounted in a box on the front wall:

 

[Travelover]

The best cure for the free solar power generation bug is to go buy a cheap $20 solar trickle charger and install it on one of your tractors.

After you discover you killed your $100-$200 tractor battery reverse powering your cheapo solar cell, you wont be tempted to cheap out on your $5000-$10,000 solar charging system that requires regular maintenance if you want the batteries to last more than 5 years.

That wall receptacle powered by the utility starts looking better and better!

There is no reason for the OP to spend even $500 for what he asked a solar system to do. As has been pointed out, a controller prevents any back flow and can also shut off any loads when the main battery gets too low to protect that battery.

 

[JOE G]

Thank you guys for the feed back, It makes sense not to go from 12 V to 120 back to 12 V, this is why i was asking as I didn't know I could charge the batteries with just a controller and panel.