How to charge 12V battery with my solar panel?

[Korwedge]

I am trying to charge a 12V battery using my solar panel. I use the battery to power a 12V fan for my homemade swamp cooler. Usually I just plug the solar panel directly into the fan and this keeps it running well in the day. I actually have to cover 25% of the panel with cardboard so the fan doesn't run too fast!

Now I'd like to use the solar panel to just keep my battery charged, and run the fan off the battery. I've been researching this for some time, but I am still quite confused. :roll:

The solar panel I am using is this one:
[url]http://www.sunshinesolar.co.uk/khxc/gbu0-prodshow/SS936A.html[/url]

The panel is 13 Watts, 14V with a blocking diode. Can I just connect the panel directly to the battery, and connect the fan directly to the battery as well? Is there a danger of overcharging the battery?

Thanks for the help :D

[BurningRando]

Yes, yes, no.

[BurningRando]

Yes, yes, no.

[Tiahaar]

Hey Korwedge! How's goin?

If you get a little 5amp solar controller and wire it between the panel and battery you can leave the panel uncovered and the battery will be charged just to the right voltage whether the fan is running or not.

Most of the controllers also have a spot to connect a load to (such as your fan or lights) and will turn them off automatically if the battery voltage gets too low, like at night, saving your battery from over-discharge too.

Its worth spending @20bucks for.

See you out there soon dude!

[mthyer]

Korwedge,

The easy way to solve your problem is to install a charge controller (as mentioned above). If you can't get a charge controller the other option is to wire a multi-meter to your battery and monitor (on a very regular basis) how your panel is charging your battery. Once its full disconnect the panel and just let it draw down your battery a while.

[teardropper]

http://www.amazon.com/Solar-Panel-Charg ... B001THQX2W

Something like this between your panel and your battery and you will do what you want and be safe. This one is $25. Remember to keep your panel clean. The dust will stick to the surface of the collector and really reduce efficiency. Solar is an excellent option for you. I'm bringing my solar this year and am curious how much sun there really is out there, how many usable hours. I think this is a good way to produce your lights, pumps, music and fans. Too bad it can't run the air conditioning, too. Then we really could put a dent in the gennies.

[MikeVDS]

Is this a car battery? If it is you don't need any of those charge controllers. 1amp (which is what your panel produces) isn't enough to do any damage to a typical car battery or deep cycle car battery which is hopefully what you're using. Just hook it up like you're both charging the battery and like you're running the fan. The fan will draw power from the panel and the battery, when it's not running the panel will just keep charging the battery.

[Korwedge]

Thanks for everyone's help!

I am using a Mity Mite battery which is setup to jump start a car. Like the kind you get at the auto store. Normally charges via AC, but it does have a cigarette adapter jack (where I usually plug the fan into).

Tiahaar! see you soon! Can't wait to see the Palomino out there!

That amp controller pictured above seems like just what I need.

[kman]

Thanks for everyone's help!

I am using a Mity Mite battery which is setup to jump start a car. Like the kind you get at the auto store. Normally charges via AC, but it does have a cigarette adapter jack (where I usually plug the fan into).

Tiahaar! see you soon! Can't wait to see the Palomino out there!

That amp controller pictured above seems like just what I need.

I would seriously consider a better charge controller than that one, however.

http://www.solarhome.org/morningstarshs ... 12vdc.aspx



Morningstar is one of the bigger names in solar charge controllers, and is very well-respected. I would definitely go this route rather than the no-name one from Amazon.

And this one is cheaper, at $20.

[Korwedge]

Now if I could just find one at a store in Seattle...

[kman]

Now if I could just find one at a store in Seattle...

Yeah. Seattle. Solar power capital of the USA. All that sun.

Spring for overnight (or 2-day) shipping.