Re: Power Wireless CCTV camera via solar panel?

["CWatters" <colin.watters@xxxxxxxxxxxxxxxxxxxxxxxxx>]

"George Leithead" <george.leithead@xxxxxxxxx> wrote in message
news:1183369050.504207.248390@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Hi all,
>
> I have a Wirless CCTV camera, that is powered via a DC12V/500mA power
> adapter.  Is it possible to make this compleley "wire free" by using a
> solar panel and a solar battery?
>
> For an example of the camera, see here:
> http://www.maplin.co.uk/module.aspx?ITAG=FAQ&ModuleNo=43937&doy=2m7#faq
> For an Example of the Solar Battery, see here:
> http://www.maplin.co.uk/module.aspx?ModuleNo=97389&doy=2m7
> For an example of the solar panel, see here:
> http://www.maplin.co.uk/module.aspx?ModuleNo=98358&doy=2m7


"Crash Gordon" says the camera needs 109mA at 12V. (Check that includes the
IR?). You need a battery big enough to power the camera through the night.
Best allow enough capacity for say 36 hours in case the next day is very
cloudy. Lets call it 48 hours to allow for the battery getting old..

0.109 x 48 =  5AH. So a standard 7 or 14AH battery should be plenty if the
solar panel can keep it charged...

The solar panel needs to provide (in 8 hours of sunshine) the same ammount
of energy that the camera uses over 24 hours....

0.109 x 24/8 = 0.327A or around 4W.

So that solar panel you looked at seems to be too small.

You would be wise to look at a much larger panel than 4W because makers
usually rate for "full sun" which rarely lasts 8 hours, particularly in
winter. I would expect a 20W panel might be needed and I would ensure that
the panel design allows extra panels to be added in parallel if the one you
choose proves inadequate. Then you can start small and add panels. Perhaps
even disconnect on in the summer if you find too much power kills the
battery life.