Solar powered lights

[naboo]

I need to replace the lights on the gate pillars at the front of my house. Lots of sun there, so figured I would go solar, but have little idea of what is good.

 

I am considering these, which I saw locally for 2600B each.

 

Specs:

 

1.6W solar cell

3.7V, 2000mAh battery

Light produces full power for 5 hours, then 25% power for 7 hours off a full charge.

 

Anyone know if this is going to be any good?

[Crossy]

OK, assuming 100% efficiency.

 

2000mAh @ 3.7V is 7.4 Watt  hours.

 

So your 1.6W cell is going to need 4.6 hours of full sun for a full charge. This sounds practical.

 

Conveniently a 1Watt LED will consume 6.75 Watt  hours when run as you note.

 

So if 1W of illumination is sufficient you are in business.

 

These units are not cheap, so you stand a chance of them actually performing as specified.

 

[Chuckles78]

I'm curious... How did the lights perform? In my experience, my solar lights have all been a disappointment.

[CharlieH]

All the solar lights I have ever bought last about 1 yr and end up in the bin.

 

I prefer standard lights, low energy bulbs,  fitted with photo-cell  in the circuit, so come on and go off according to time of day. They have been in place now for 5 years without issue.

[Stray]

I have been experimenting with solar powered lights and, contrary to previous comments, have been having very positive results.

 

Along a walk-way, I've installed 10 x Eve Lighting 1 Watt motion sensor LED lights.  These turn on automatically when light levels are low but become brighter when the motion sensor is triggered.  They also have two lighting options.  'Day' or 'warm.'  More than happy with these units.

 

Bordering the driveway are 12 x Luzina (33615-GY) garden lights.  Not so bright so they don't shine in your eyes when parking and turning in the drive but make good 'marker' lights for the drive-way edges.

 

In a rockery (reptile sanctuary) are 5 x Eago 'Hide and Seek' spotlights.  These have 3 x LED's each.  Whilst very bright, the three LED's have a tendency to drain the battery quickly and, from sun-set, usually turn off (deplete the battery) by 4am.

 

I also purchased some very cheap, small garden post lights also by Eago.  These are available in several different colours (I have one white, one yellow and one purple).  I've affixed these lights to floats and have set them loose on a fish pond.

 

In all of the above units, except the floating fish pond lights, I immediately replaced the batteries.  They come with 'no-name' Nickel Cadmium (Ni-CD) batteries but I replaced them with Varta and Energizer Nickel Metal Hydride (Ni-MH) batteries.  One of the alleged benefits of Ni-MH batteries are that they are not supposed to suffer 'memory effect' to the same degree as Ni-CD.

 

The units with the replacement Ni-MH batteries have all been operating for over 2 years.  The cheap floating lights have been operating for less than a year and, when they finally fail, I'll use the 'no-name' batteries that I pulled from the other units.

 

I've also purchased some Sanyo Cadnica (Ni-CD) batteries which I want to experiment with.  I'll buy two more light units and put one of each battery (a Sanyo Ni-CD and a Ni-MH) in them and see how they perform over the long term.

 

With regards to those who have posted about solar lights not lasting, is it the light unit (itself) that is failing or just the battery?  I did have a few earlier failures with solar powered lights but, in every case, it was due to poor quality batteries and not the actual lighting unit.  In the heat of the sun the batteries would rupture, leak and damage the light unit internals.  One battery exploded and cracked the solar panel.  (The manufacturers really need to put a little more thought into the selection of the batteries that power units that sit in the hot sun all day.)

 

The reason for my using solar powered lights is that I live on a very large, sprawling property.  When the cost of digging long trenches, installing conduit and cabling, re-landscaping, electrical safety and on-going running costs is compared to the cost of replacing batteries every few years . . . needless to say, I'm a convert!