# Solar/Charge controller?



## Master Brian (Apr 24, 2009)

I have a small, 144sqft plus 100sqft loft cabin/shed on some ground several hours away from me. It's pretty dense with trees, in a forest on a lake. 

1st question is: Eventually, I plan on installing a 300watt solar panel and installing some batteries to basically power some led 12v lighting, maybe power some 12v fans and charge cell phones, etc.. I'm not looking for much. For heavy power use I'll run the generator, I just want quiet at night. We are only there maybe 1 weekend a month, if that, so the panel will just act as a trickle charger/ maintainer for the batteries to help a bit while there and recharge when gone. I've run 3 of those 12v fans overnight on my marine stroller battery with seemingly very little drain in it, so hoping I'll be fine with 2-3 batteries. Not sure what route I'll go on them yet, still looking into cheap easy to acquire them....I have some leads that replace batteries for commercial solar systems way early for fail safe. 

Anything sound bad about this? 

2nd question, I have a trail cam I want to power while away until i am ready to implement a bit bigger scale like above. I have an older auto battery, that still holds a charge being given to me. I also was offered a 10"x10" 1.5watt panel that's sitting unused on friends RV. The trail cam runs on 6 C cell batteries or 12v DC plug. 

Obviously a car battery isn't ideal even though way bigger than trail cam probably needs, but it's free and if it dies it dies, I have a core for something better if that happens. 

If I go this route, do I need a charge controller? I seriously doubt I'll get 1.5watts output if that panel is rated for that. I found a $15 20amp solar charge controller on Amazon abs it has two usb ports so I could charge cell phone's on it as well. My friend that's been installing the 300watt panels on his RV says that controller is too big. Is that really possible or is it just overkill and still work? It'd be my only cost and is $15. I see smaller ones without usb for only a few dollars less. 

This second scenario is just to play with and see what % I can get from a panel. If 1.5watts, do I get 1watt, 1/2watt, etc.... that's what I'm hoping to find and then see how charged the battery is when i leave vs return. Until i get structure wired for 12v with lights, etc., I just have no way of knowing need. I might find I don't even need the 300watt panel or that I'll need more. 

Thanks for any incite.


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## Oso954 (Jun 23, 2012)

You’ll get More bang for your buck by buying a new 1.5w system than adding a charge controller to the old panel.
https://www.harborfreight.com/15-watt-solar-battery-charger-62449.html?cid=paid_google|*PLA+-+All+Products|All+Products|62449&utm_source=google&utm_medium=cpc&mkwid=s|pcrid|327822404853|pkw||pmt||pdv|t|slid||product|62449|&pgrid=71439424048&ptaid=pla-309600160537&pcid=1688396772&intent=&gclid=EAIaIQobChMIvbWojY6G5QIVFdVkCh1-8w6NEAUYASABEgIE3vD_BwE

On the 300w system, yes get a charge controller. Preferably a MPPT charge controller.


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## Marson (Jan 26, 2018)

Master Brian said:


> I have a small, 144sqft plus 100sqft loft cabin/shed on some ground several hours away from me. It's pretty dense with trees, in a forest on a lake.
> 
> 1st question is: Eventually, I plan on installing a 300watt solar panel and installing some batteries to basically power some led 12v lighting, maybe power some 12v fans and charge cell phones, etc.. I'm not looking for much. For heavy power use I'll run the generator, I just want quiet at night. We are only there maybe 1 weekend a month, if that, so the panel will just act as a trickle charger/ maintainer for the batteries to help a bit while there and recharge when gone. I've run 3 of those 12v fans overnight on my marine stroller battery with seemingly very little drain in it, so hoping I'll be fine with 2-3 batteries. Not sure what route I'll go on them yet, still looking into cheap easy to acquire them....I have some leads that replace batteries for commercial solar systems way early for fail safe.
> 
> ...



I'm by no means an expert on this stuff. These are just some random observations. I have a similar cabin to yours. It's kind of a unique setup for solar which is hard to find information on....I use power occasionally, draw the battery down some, and then have weeks to recharge it. I figured a small solar panel would sort of trickle charge the battery. Biggest problem is the batteries don't like it.  



I went the 120 volt route, with a pure sine wave inverter hooked up to a lead acid battery. I have lights (CFL bulbs. Getting LED bulbs is on my to do list) and I charge several phones and that's about it. I went the 120v route because at the time I wired the cabin, LED's were not yet common and I would have had to use #10 wire to accommodate the startup draw of the CFL bulbs. Plus the hardware for 12V really isn't there. You'd have to use cigarette lighter adapters for charging your devices.



The battery is just a single cheap marine deep cycle battery. works fine in the summer, but not so good later in the year, and the biggest problem is that the battery life sucks. I was going through a battery a year. I think with such a small solar panel, if the battery gets drawn down, it sits around discharged and shortens the life. At least thats my theory. So maybe I just need more batteries.


I ought to upgrade the solar panel-charge controller-battery setup one of these days. I'm thinking of trying a Lithium battery which I could charge at home and bring up for backup if nothing else (Lithium being much easier to lug around than a stinking lead acid battery). Sucks when you lose power in the middle of a winter evening. You can buy used lithium batteries on ebay from medical carts for a reasonable cost--still trying to figure out if and how I would charge 12v lithium battery. Also wonder if a lithium battery would be more forgiving with my solar charge setup. 




This guy has some good videos about solar: 





Pretty sure you need a charge controller, although with a free battery these isn't much to lose I suppose.


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