I'm dragging my solar powered entry light out of the closet. Just as a background I designed a Pic based controller to monitor sunlight to determine when to turn the light on and off again. It also monitors voltage levels of the battery and turns the light off when the voltage level is low.
It has an off the shelf charge controller and I am using an off the shelf buck puck to power the light.
The light itself takes less than 700ma. I have not calculated the consumption of the pic controller and charge controller but I can't imagine it amounts to much.
The panel is an old panel that has been around for years and needs replacing.
The whole thing is working great with the exception that that duration that the light is on is slowly decreasing. I suspect that the battery is becoming sulphanated. The battery is much more than a year old. Also I have the voltage level to turn off the light at 10V and I am thinking that is also taxing the battery.
The current battery is a 12 6AH SLA.
I'd like to replace the panel and battery.
I was thinking this
http://www.amazon.com/Instapark®-Bl...8&qid=1349794737&sr=8-21&keywords=solar+panel
for a panel and maybe a 18 to 24AH SLA
Is this a good choice? Is it overkill or should I go with a higher wattage panel?
My thinking is that we have days where there is little sun and it would be nice to be able to maintain a charge enough to light the light over a couple of days with little sun without taxing the battery much.
It has an off the shelf charge controller and I am using an off the shelf buck puck to power the light.
The light itself takes less than 700ma. I have not calculated the consumption of the pic controller and charge controller but I can't imagine it amounts to much.
The panel is an old panel that has been around for years and needs replacing.
The whole thing is working great with the exception that that duration that the light is on is slowly decreasing. I suspect that the battery is becoming sulphanated. The battery is much more than a year old. Also I have the voltage level to turn off the light at 10V and I am thinking that is also taxing the battery.
The current battery is a 12 6AH SLA.
I'd like to replace the panel and battery.
I was thinking this
http://www.amazon.com/Instapark®-Bl...8&qid=1349794737&sr=8-21&keywords=solar+panel
for a panel and maybe a 18 to 24AH SLA
Is this a good choice? Is it overkill or should I go with a higher wattage panel?
My thinking is that we have days where there is little sun and it would be nice to be able to maintain a charge enough to light the light over a couple of days with little sun without taxing the battery much.