Running a 12v fan off this solar panel?

soundb0y

soundb0y

soundb0y

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Can someone try and please help me understand the black magic that is electric?

I have a solar panel at home with the following specs:

https://imgur.com/a/DXRDtb3 (how do you insert images now!?)

I am looking for the cheapest and easiest way to hook it up to a 12v radiator fan. The one I was looking at was 80w I think.

It only needs to come on when the suns out so wasnt going to bother with a battery, but will the 19v damage a 12v fan?

Do I need to put something in the line to regulate voltage or will it be ok? I heard solar doesnt always put out max voltage anyway?

If its cheaper or a lot easier to just get a new panel Id do that.

Thanks
 
I've made a solar fountainover weekend but that's usb output so pretty standard, i would think myself up to 15 v OK as a car alternator kicks out up to that on a 12v system but a steady 19v may be pushing it, if it were me I would slap a voltmeter on and measure, someone with more knowlage than me may know!!
 
80w is a big fan!. The problem you are going to have other than the voltage mismatch, is even if you regulate it down most of the time unless in bright sunshine you are going to be making less than 80w and the fan won't have enough torgue to start turning (or in some cases keep turning and it'll sit there stalled and burn out)

Solar panels also have whats called a Maximum power point (you see some reference to that on the label), thats effectivly a 'sweet spot' at any given time in terms of what load is most opitimal to present to the panel, too low and you are not making use of as much as you could, too high and the volatage collaspses down and you don't get what you want. Inverters and charge controllers have an MPT tracker to keep tabs on this and try and extract the optimal amount.

You are best off looking for a charge controller for a 12v battery and a battery to match. But even then, do not expect to be about to run an 80w run for all hours between sunrise and sunset, you wont be storing enough energy for that
 
soundb0y said:
...but will the 19v damage a 12v fan.
Click to expand...

Arguable the voltage won't be the problem but rather the draw of the radiator fan especially at start-up (inrush current) which is why radiator fan circuits can be rated for 30/40A+. Even then, the figures of the solar panel are maximums @ optimal sunshine intensity.

Personally i'd use a controller and battery for the supply and then a PIR/photocell switch to trigger the fan. Or you could use a threshold switch circuit, using the solar panel voltage as a trigger, and switch a relay (for the fan).
 
Thanks for the info all. Im guessing 19v is the max output so probably with our weather it wont be pushing flat out all the time?

Funnily enough I actually found an old car radiator fan in the shed (not sure what wattage) so thought I'd try it as nothing to lose. I just wired it in directly and it seems to work. Pretty good power when the suns directly on it and slowly reduces when a cloud comes over.

If I wanted to put an inline on/off switch on it would that have to be anything special or just find something the correct size?

I think I may actually need to double up with another fan so think ill watch how this goes for a few days and as long as its not on fire or anything will probably do the same. Fans seem cheap about £20 and panel about £70 on amazon.
 
Sounds like you're trying to hookup a ghetto solar-powered fan? If so, i'd introduce an old 12v car battery & the cheapest solar charge controller you can find on eBay into your setup. You can have it ruining a bit in the evenings then too.
 
Ghetto solar fan was exactly how I described it to my mate ha.

Thought about a battery as we usually have a few lying around, but would it have enough juice to charge the battery and run? I read that if it keeps draining the battery it wont last all too long? Would be ideal though.
 
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