diy AA Solar charger?

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4,539
Location
Lima, Ohio, USA
So my friends mom is slowly building a Homesite near where she grew up( about 5 mi from me. She lives up in Alaska) Put up a small shouse last summer, but no power to the site yet. She has some trouble Making relatives next door, who she thinks have been "breaking in"( place has mostly been unlocked). She replaced the locks, added a deadbolt, she wants to put up some fake security cameras, I picked up a couple that take 2 AA's to blink a little red LED. The batteries are supposed to last 90 days, but I'm interested in adding a solar charger into the mix, so I don't have to go preform obvious maintenance every few months... Any suggestions?
 
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3,656
Location
Worst Case, Ontario
I guess you can't really invest in a decent solar system if it is just going to get stolen. I think I would try to find a way to add more batteries in series than invest in the most rudimentary of solar systems. It would certainly be cheaper and if it gets pilfered you are out the cost of some AAs. You could purchase an external AA battery back and then connect it to the - and + terminals on the security camera instead of using the internal battery compartment.
 

AVB

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1,461
Location
Georgia
Buy a couple solar lawn lights and steal the rechargable cells and chargers out of them. You can find the single lights for $1 each.
 
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35,728
Location
ME
I'd use game cameras. They're meant for long life on a set of batteries. Plus she could plausibly say she wants to see what's been crawling around her property. Long pig. LOL You only own, what you can defend. The neighbors know this.
 
Messages
4,539
Location
Lima, Ohio, USA
Originally Posted by CT8
Buy a real security system a low end one that records isn't super expensive.
That might be an option if there were utilities run to the site, but... There's not...yet.
 
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1,583
Location
Cincinnati, USA
With the batteries lasting 90 days, it is clearly a very low drain rate. It is difficult to even estimate the available mAh of rechargeables at such a low rate as nobody tests it. Nobody that I'm aware of tests that and with non-LSD (low self discharge) cells, the self discharge rate can be as high as the LED drain rate. Regardless, let's suppose a decent LSD AA like Panasonic Eneloops can achieve 2500mAh at that drain rate. That's 28mAh per day. It's such a low rate that you don't even need a charge controller, to just hook up a tiny solar cell directly to the batteries' series +/-, as long as the (full sun) peak voltage of the solar cell is not enough to damage the LED blinker. This is the part you should measure, having the batteries fully charged, solar cell in the strongest sun of the day, to see what the peak voltage is. I don't know what lifespan you expect, but those cheap landscape light solar panels tend to only last a few, around 5 years if that, but maybe that's enough, except that is too much solar panel for a 28mAh/day drain rate. It will overcharge and cook the cells eventually, and some of them are only meant to recharge a single cell and may not even develop enough voltage, so really you want closer to 1/4th the cell size then two of those in series for higher voltage. It could be quite time consuming to try to hunt down such a specific tiny solar cell unless you happen upon an electronics surplus site that has them, so the more practical solution is shop by price and what you feel you can easily weatherproof, then use a series resistor to reduce current to an accept able level, say below 40mA in full sun should work, but don't forget to have a series diode in place between the solar panel and batteries when measuring current to determine the right resistor value. I should've mentioned the diode earlier, that you need one between the panel and the battery to prevent backwards drain when the panel is putting out lower voltage than the batteries. It also needs added to the cell voltage since a silicon diode will have about 0.6V at this low current and a schottky about 0.2V. Considering the time to make this, including a weatherproof housing, and that you only need a tiny solar panel, it seems like you would be better off buying a ready made product, then measuring its full sun output and putting a resistor in series to limit charge current a little below 40mA in full sun as suggested above. Don't forget about snow and ice. Solar panels don't work so well when covered in them. You might want to position the panel so it is facing a bit away from the normal jet stream so less snow deposits on the panels, even if you have to settle for lower power production due to it because again, this is a very low power requirement of even the smallest panels (except maybe something super tiny for a watch or calculator).
 
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Messages
4,539
Location
Lima, Ohio, USA
Originally Posted by eljefino
I'd use game cameras. They're meant for long life on a set of batteries. Plus she could plausibly say she wants to see what's been crawling around her property. Long pig. LOL You only own, what you can defend. The neighbors know this.
Def. a good suggestion. one she might go for...( she's taken down a few Moose during her time in the North, even brought me some homemade Moose jerky a few years back) and when i said the neighbors were trouble maker relatives...nobody's stealing anything, they're being purposefully Petty and trying to get the law involved in things they(the law) have no time or need to be involved in... this could get a bit long... It's her Ex Husband's Brother and His wife. she bought the land next to them. (at the time I suggested doing so might lead to some...issues...."no, i get along with them fine, just not [the Ex].") she has the property surveyed. Turns out brother in law's Fence is 2 feet onto her Property(and he's got stone driveway all the way to the fence). and one of his Trees is on Her side of the line.(and his burn barrel, and a trailer that hasn't been on the road in 5 years, etc) he says well a couple of the posts are Rotten, so the fence had to come down anyway. then he says he wants her to pay him like a grand for the blue spruce that he planted on her side of the property line. (umm..no..) Better part of a year goes by, before they move the fence, but they call the township to come inspect the property, b/c the grass and weeds were over grown. (initially HE was going to mow it since he lives next door). and tell they inspector that her wood stove in the shouse isn't installed properly and is in code violation.( how would they know that if they weren't poking around inside, for the record, it wasn't installed at all. she bought the stove last fall, put it and the pipes,et all just inside the place. but made no effort to install it at that time.) so she gets a call - in Alaska - from one of the township trustees, that she needs to have it mowed., and a short discussion on building codes, yadda yadda. so now she has a guy who lives up the road comes and mows it once a month or so.(she grew up on this road, knows everybody out there) nosy ex sister-in law also had called some "plant expert" out to identify what was growing in the lot, and apparently "they found several types of noxious weeds!" she's also called the township about the car that's been parked there for several months " she has people living in there, and it's not a legal residence" or something..i can't remember the exact wording, but yes, it's basically a 2 car Garage, with a little 12*20 studio up front, with no plumbing, electricity, running water, etc. but no, no one is Living there. if her oldest son comes up from columbus he might sleep there for a night or 2, but nothing more than camping. the only reasons that car has been parked there, are 1) it's the car the owner's son had with him @ Fort Hood, and he got deployed to Korea, so they shipped it back home, and 2) the plates expired in Jan. day before yesterday I go over there to help them paint the Shouse. they whole time the group of us is there painting,( 4 painters, and one handy man inside properly installing the stove, and building in a staircase to the lofted storage above the Studio) there's "Gladys Kravitz", in her dressing gown, standing at the end of the fence, taking pictures/filming us with her phone,.. we'd just turn and wave.. so you know, the FUN kinds of family drama....OI!
 
Messages
4,539
Location
Lima, Ohio, USA
now, a hypothetical for y'all... in the "Garage" portion she's put in a wood stove for heat (she's generally back here sometime in the thanksgiving-christmas period), and they're prodigiously insulating the Studio portion. I kinda want to build(with the owners permission of course), a flue mounted coil type water heater, pipe the hot water over to the studio, and run it through a radiator. (could possibly get by with an auto Heater core, oil cooler, trans cooler, etc.) thinking wrap some copper tube around the flue, route some inexpensive tubing the 15' or so (so 30' of tubing)through the wall, and into the rad.. will i need a fan? getting the whole thing to run passively via convection would be Ideal... but im not an engineer, or a plumber, or mechanic, and have never studied fluid dynamics or thermodynamics. any pointers?
 
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