Solar Powered Landscape Spotlights

[earthsaver77]

A solar powered landscape spotlight or set of lights is needed for security and visual appeal.
It is hard to find ones that match their claims, and the market is flooded with junk.
In your experience, what is a good choice for under $50 that will keep a relatively consistent brightness for at least four hours?
I expect significant dimming over a whole night, but one that still casts enough light to see movement until sunrise would be great.

 

[idleprocess]

It is hard to find ones that match their claims, and the market is flooded with junk.

Indeed. Between the rapidly-degrading solar cells, Z-grade batteries, and bottom-scraping cruftsmanship of the electronics you're going to be lucky to find units that last one hour after a year. Seems that - much like anything internet connected that's also stationary - running a wire results in superior performance.

 

[ilikeguns40]

I agree with idleprocess. Running a wire will result in many, many years - if not lifetime lighting needs if done correctly. Way better performance and less aggravation over the years

 

[bykfixer]

I'm in year 2 with a pair of these dudes from Home Depot. The battery stopped charging after a few months so I just replace them as need be.
They throw light about 20 feet for about 6 hours with new batteries.

 

[ilikeguns40]

What size batteries those rock lights take? I guess just recharging and replacing batteries is a good idea, as long as you don't have 100 of them

 

[Dave_H]

I've been playing with solar garden lighting since LEDs started being used. Yes there is junk out there, and some I would not technically call junk but not all that great; but some decent quality if you look around. Home Depot has some good stuff. Buying online risks getting some of the worse stuff. I won't recommend particular vendors or models. Unfortunately you often need to do your best guess, try it out to see how well it works.

I would not expect more than a few years' life for most low-cost solar garden lights if left out all year. Common downfall is physical damage (including hitting with a shovel when clearing away snow). Other failures include moisture buildup and corrosion of switches and battery contacts. Sometimes the cell dies despite all else looking OK, due to poor management of charge/discharge.

Solar light expectations need to be realistic. You can't get all the brightness and runtime of a wired light, and solar needs good sunlight to work well.

Cells are not all bad, but usually not name-brands. I have good luck with Lithium Iron Phosphate which replaces three 1.25v cells in some designs; 14430, 14500 and 18500 being common. Have to be careful with temperatures below freezing though; and on the very high side.

I've developed a quick estimation method for realistic runtime based on the size/type of solar panel, battery capacity and some idea of the LED current. Vendor runtimes often assume ideal sunlight, which needs to be factored in.

Dave

 

[funkymonkey1111]

This is not a spotlight, but I will tell you these things work great. I don't know exactly how long the charges last, but with a good Colorado blast of sun the lights are still going strong at 2am. I've had them over a year and they run off one rechargeable AA. I've not had to replace any of the batteries in the lights.

https://www.costco.com/tommy-bahama-solar-led-pathway-lights,-6-pack.product.100840745.html

 

[Dave_H]

I'm in year 2 with a pair of these dudes from Home Depot. The battery stopped charging after a few months so I just replace them as need be.
They throw light about 20 feet for about 6 hours with new batteries.

The solar rock lights have been around for a while, have a few small ones which are still holding up, but light output is limited. What type of cells in yours? One of mine uses 1/3AAA 200mAh.

Dave

 

[Dave_H]

Indeed. Between the rapidly-degrading solar cells, Z-grade batteries, and bottom-scraping cruftsmanship of the electronics you're going to be lucky to find units that last one hour after a year. Seems that - much like anything internet connected that's also stationary - running a wire results in superior performance.

Solar garden lighting obeys the laws of physics; and economics if you can actually call them laws. Arguably the industry is just giving consumers what they want, cheap product some of which lasts marginally long enough, at which time it's time to get something new anyway (for some people).

I don't like the extra waste from low-quality products (of any kind). Also, some low-end lights require taking apart to get to the cell(s), many I suspect just get tossed, not good as some still use NiCd. I still buy cheap to test out, open up, use, maintain, sometimes modify, then properly dispose or give away.

Having opened up many garden lights, the electronics is usually pretty simple, given the cost, especially if it's direct drive to LED (3xAA or 1xLiFePO4) typical on small spots.

Not sure what you mean by "rapidly-degrading", I have modest-priced lights which have been out in the sun for years. They gradually decline, usually visible on crystaline panel surface getting cloudy. I rarely see visible defect in amorphous panels.

Home Depot has a deal on small spots for around $10. They looked decent but did not buy one at the time as I have enough garden solar for now. This one uses 18500 LiFePO4 cell which should last a long time although replacements are not exactly cheap.

So if the OP needs high brightness and predictable runtime, wired-in lights may be better, but these come with their own costs and downsides.

Not what the OP is asking for but just to throw this in, I've checked a couple of bottom-end small spots from Dollar Tree ($1.50 each). Light output is feeble but enough for the place where there is none; and they hold up surprisingly well. Amazing they can be produced and sold at this cost. Construction is good for this level. The 100mAh AAA NiCd seemed a bit low, so was replaced with 200mAh; anything higher is overkill.


Dave

 

[bykfixer]

The solar rock lights have been around for a while, have a few small ones which are still holding up, but light output is limited. What type of cells in yours? One of mine uses 1/3AAA 200mAh.

Dave

 

[SCEMan]

I have a couple sets of solar landscape lights I picked up at Costco 2 years ago and they've been great. Rain, snow, freezing temps and they're still going strong. Just added 4 solar spotlights from Amazon. So far so good. Also have a bunch of metal spinner flowers with solar lights and so far so good.

 

[idleprocess]

Arguably the industry is just giving consumers what they want, cheap product some of which lasts marginally long enough, at which time it's time to get something new anyway (for some people).

The market definitely responds to cheap. The undesirable consequences on the backside of that bargain is reflected by this post.

Not sure what you mean by "rapidly-degrading", I have modest-priced lights which have been out in the sun for years. They gradually decline, usually visible on crystaline panel surface getting cloudy. I rarely see visible defect in amorphous panels.

Multiple neighbors seem to go through sets of these things annually. Since they're positioned as path lights I can easily inspect them from the sidewalk; the panels are visibly clouded after some 6 months at which point their ability to produce even one hour of full brightness is marginal. I imagine the panels are encapsulated in something like polycarbonate lacking UV inhibitors which is what's degrading. It's possible that these are megalomart specials where every possible corner has been cut.

 

[Dave_H]

View attachment 44450

At least AA or AAA is easy to replace. Some lights use 2/3AA or 2/3AAA. BTW you could get away with 400-600mAh NiCd which has lower excess capacity for light of that size, and should tolerate overcharge better if it ever reaches capacity.

Dave

 

[Dave_H]

The market definitely responds to cheap. The undesirable consequences on the backside of that bargain is reflected by this post.


Multiple neighbors seem to go through sets of these things annually. Since they're positioned as path lights I can easily inspect them from the sidewalk; the panels are visibly clouded after some 6 months at which point their ability to produce even one hour of full brightness is marginal. I imagine the panels are encapsulated in something like polycarbonate lacking UV inhibitors which is what's degrading. It's possible that these are megalomart specials where every possible corner has been cut.

I see your point; higher sunlight at lower latitudes e.g. Texas plus high ambient temperature likely speeds up degradation. Even a small spot on a window sill here which is behind glass (which should give some protection) is showing signs (mostly cloudiness) but it takes at least a few years.

Is there a good clear protective tape for this, which stands up but does not impact effectiveness: or a clear spray coating which is not going to yellow or otherwise defeat the purpose, and is fairly easy to get?

What's the word on degradation of amorphous panels? They have lower efficiency (8% v. 14-18%) therefore larger for similar capture, but used on various solar lights including spots.

Meanwhile I decided to check out a Hampton Bay solar spot from Home Depot (usual disclaimer, not an endorsement of either company). Cost $9 after tax, surprisingly good for this price; good light output/duration, sturdy, but can't tell how UV resistant is the solar panel. More detail a bit later.

Dave

 

[Dave_H]

Meanwhile I decided to check out a Hampton Bay solar spot from Home Depot (usual disclaimer, not an endorsement of either company). Cost $9 after tax, surprisingly good for this price; good light output/duration, sturdy, but can't tell how UV resistant is the solar panel. More detail a bit later.

Dave

Hampton Bay solar LED spotlight 55 lumens Model 72301-03 SKU #1006685121 .

This light has crystaline panel (I assume mono-) approx. 10 sq. in. area. Cell is 18500 LiFePO4 1000mAh. Up to 150mA peak charging current was measured in bright direct light. Over a good sun day, most or all capacity could be charged, cell appears to be right-sized.

Two points on LiFePO4: it should not be charged below -5C. Winters here can go below this, sometimes down to -30C or lower, so this is not an all-season light for some locations. Running overnight for more than 8 hours, cell voltage was down from 3.3v to 2.6v, still some light output; not sure how much further it goes. Over-discharge is not good.

Crude estimated available charging power available based on 1000 watts/sq m. and 14% efficiency works out to 0.9W, roughly 260mA at 3.45v. In reality it's lower.

Opened up the panel pod, construction looks good; on PCB is a small 5-pin IC which is charge controller, expected in good design.

LED draws around 120mA at 3.3v, which is 0.4W. Output claimed is 55 lumens which suggests 139 lumens/watt; sounds optimistic, but possible. In any case the light output is very good, well defined warm white pattern.

Dave

 

[Dave_H]

So that's it for discussion, no further recommendations or ideas, and is the OP still lurking?

I would still be interested to find out more about UV-resistant coating, spray, film or tape etc.

Hampton Bay spot is outside now for general testing though I expect an UV effects will not show up this year.


Dave

 

[Dave_H]

Hampton Bay solar LED spotlight 55 lumens Model 72301-03 SKU #1006685121 .

Spot is still holding up fine after a few months.

It occurred to me that this light has a complete low-cost charging system and cell which can deliver nominally 3.3v for a small remote project such as wireless telemetry etc. for anyone who is into this. Limitation is still there that it can't operate in sub-freezing temperature without damage to cell.

Dave

 

[HarryN]

Apparently there are some AA powered solar garden lights / camping lights at Walmart.

I have not picked them up yet but it was suggested by someone on a camping van forum that I frequent. (they didn't give a model )

I have some pretty decent low current rate 2850 mah ansman NiMH batteries that I use for similar applications. Thinking about getting some for camp site type stuff.

_________

As far as garden lights - we have had some I think 12 vac or 24 vac lights on a timer that are run through wires to the various gardens. I can't say that it has been all that reliable. Part of the reason is that rodents like the wires, and partly because the lights just are not all that great.

 

[idleprocess]

I see your point; higher sunlight at lower latitudes e.g. Texas plus high ambient temperature likely speeds up degradation.

It's almost 23:00 and outside air temperatures have dropped to 95F/35C after peaking at 106F/41C around 15:00. Along with such balmy temps comes clear skies and greater than average UV. While this isn't all six effective months of summer that the region sees, it's now typical June through August. Almost everything plastic that wasn't given a healthy dose of UV inhibitors during the production process left outdoors in the sun suffers for it.

All but one of the neighbor's solar lights are thoroughly dead now. Another neighbor has what appear to be their original better-quality units from last year; we shall see if they survive the summer. Yet another more distant neighbor has some more professional streetlight substitute solar lamps that have been running for years, however those for sure aren't sold at the megalomart for five bucks apiece.

 

[Dave_H]

Spot is still holding up fine outside in Ottawa (Ont.) sun, but will need to come inside in a few months due to low temp. Pity, it's solidly made, got another one.

Dave

Spot is still holding up fine after a few months.

It occurred to me that this light has a complete low-cost charging system and cell which can deliver nominally 3.3v for a small remote project such as wireless telemetry etc. for anyone who is into this. Limitation is still there that it can't operate in sub-freezing temperature without damage to cell.

Dave