# Output of solar panel on solar landscape lights?



## LEDrock (Mar 14, 2017)

I got 6 of those solar landscape lights and found that the AAA battery in them charges up in just a few hours in the sun. Since the battery is removable, it got me to wondering if these lights could be used as an emergency charger for other things if I use a couple of wires connected to the battery connectors and lead then to AA batteries or something else. I've tried to find info on the output of the little solar panels on the top of the light to get a better idea of its output but haven't found anything yet.


----------



## Lynx_Arc (Mar 14, 2017)

LEDrock said:


> I got 6 of those solar landscape lights and found that the AAA battery in them charges up in just a few hours in the sun. Since the battery is removable, it got me to wondering if these lights could be used as an emergency charger for other things if I use a couple of wires connected to the battery connectors and lead then to AA batteries or something else. I've tried to find info on the output of the little solar panels on the top of the light to get a better idea of its output but haven't found anything yet.


The batteries that come with solar lights can be rather low capacity at times and often nicads that handle overcharging well if they have ~300mah batteries taking 2 hours an 800mah nimh could take 8-12 hours to charge fully and if overcharged could damage them reducing their lifetime and/or capacity.


----------



## LEDrock (Mar 14, 2017)

Lynx_Arc said:


> The batteries that come with solar lights can be rather low capacity at times and often nicads that handle overcharging well if they have ~300mah batteries taking 2 hours an 800mah nimh could take 8-12 hours to charge fully and if overcharged could damage them reducing their lifetime and/or capacity.



Would you happen to know what the amount of power generated by the light's solar panel is? I was thinking that the power output of the panel could help determine the amount of time it would take to charge a battery of a higher capacity, or maybe even power a device directly if multiple panels could be linked together somehow.


----------



## Lynx_Arc (Mar 14, 2017)

LEDrock said:


> Would you happen to know what the amount of power generated by the light's solar panel is? I was thinking that the power output of the panel could help determine the amount of time it would take to charge a battery of a higher capacity, or maybe even power a device directly if multiple panels could be linked together somehow.



I haven't a clue as panels differ in output and size too and circuitry can also have an effect on things. I'm guessing the output may be as much as 100ma in bright sunlight that would charge a 300ma battery in 3-4 hours I estimate


----------



## LEDrock (Mar 16, 2017)

Lynx_Arc said:


> I haven't a clue as panels differ in output and size too and circuitry can also have an effect on things. I'm guessing the output may be as much as 100ma in bright sunlight that would charge a 300ma battery in 3-4 hours I estimate



Thanks! I was thinking of possibly combining a number of them in order to increase output so that they could do more. It might be a fun little project. The idea of getting free electricity from the sun is kinda neat.


----------



## Lynx_Arc (Mar 17, 2017)

LEDrock said:


> Thanks! I was thinking of possibly combining a number of them in order to increase output so that they could do more. It might be a fun little project. The idea of getting free electricity from the sun is kinda neat.



Depending on the battery type to be recharged you could have future issues as "dumb" high current chargers are not the best thing for nimh and lithium ion batteries and if high enough output can still cook nicads too greatly reducing cycle life. 
Personally I found that unless your power company charges you outrageously high prices for electricity the savings can end up so small that the hassle involved may not be justified. I think one time I estimated the cost of charging a AA eneloop type nimh battery at about 10 cents per kwh and figured you could charge a battery for less than a penny in a smart charger and that would give you more optimal cycles out of your battery so saving that fraction of a cent to charge a battery could end up costing you cycles of battery use that may actually in theory lose you money. If let's say a battery normally if charged properly can last 500 cycles and cost $2.50 total that is a half a cent a cycle but loss optimal charging reduced the cycles to half raising the cost of a cycle to a penny as cycles drop to 250 so you lose half a cent to save half a cent and have to work around solar charging quirks etc. In other words saving money by solar charging may not be saving money as you may find yourself spending more time with that method such that going out and doing an hour worth of work and making $5 for it even could find you a lot more profitable than messing with mediocre (or perhaps even lousy) solar charging solutions.

All in all though I agree it is fund to find ways to save money (doing inexpensive hobbies) and solar power is cool. I once thought about getting a solar charging setup with nice panels and such but did the math and for my purposes it is a bad investment as i have never needed solar charging as in cases that I would need to be away from charging solutions I could just stock up on batteries for that occasion and come out astronomically cheaper than solar setups. 
My advice is to see what voltage you are getting from the panels natively perhaps if you can get 5v you could use a usb power bank to absorb the power from the combined solar arrays and with the power bank you wouldn't need to worry about regulation on charging plus you would have compatibility for use with other devices.


----------

