On 12/01/2018 18:55, Rod Speed wrote:


The point is that with PIRs, the lights are on a hell of a lot less,
so more chance of being able to get enough power from solar.

True but it also depends on how much light is required.

My PIR operated solar LED light (the one still working after 3 years)
illuminates around 3 x 3 metres of lawn and path area bright enough to
easily see what's on it but it is fairly bulky and has a solar cell of
20cm x 15cm. The light is constructed of 40 individual discreet LEDS.

A few more things I've observed with some solar cell lights:

Many of the cheap Chinese sourced cells have are encased in a clear
expoy?? for waterproofing. This goes milky when exposed to the sun for
more than around a year reducing efficiency, even during the Summer.

The best solar cells on lights that I've purchased are behind a sheet of
glass.

Even though the (sealed) battery compartment may look adequate the
battery fitted may be small with limited capacity. Although not
relevant to the OP application the £1[*] solar cell spike lights for
identifying garden paths with a dim glow used to come with a AA size
battery. Recently I purchased a couple from different places (I wanted
the solar cell) and found one to be fitted with a half AA size battery
and the other with something akin to a quarter size AA battery.
[*] sold for £1 to £2 each in many retail outlets but at 5x the price on
TV shopping channels.


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