One of the conveniences of the WB4SON Shack (called the “Wombat Room” by family members), is a 40 Amp 12 VDC power bus, normally fed by an Astron linear power supply. It is also fed by a 110 Amp-Hour deep cycle battery which takes over when grid power is down. The battery is kept charged by a 40 watt solar panel (with charge controller) mounted on the roof with a good southerly exposure.
So it’s a good thing to know that WB4SON can stay on the air during an ice-storm, or rare hurricane, but up until recently lighting the Wombat Room was performed by flashlights. That has changed with the addition of some LED lighting designed for 12 VDC systems.
My first attempt was to use some under-cabinet LED strip lights that were a tad shorter than 4 feet. I simply mounted these next to each T12 40 Watt florescent lamp in the room. When power died I turned on the DC strip lights. While they provided some nice atmosphere, the lighting left something to be desired.
I’ve improved things by adding two suspended LED lamps that are closer to the work surface and provide substantially more light. These are made by a company called Goal Zero. Amazon sells these for about $35 each including shipping.
The lamps have 9 foot long DC power cords. A custom carabiner allows you to hang the light at any level. Multiple lamps (up to 12) can be chained together. The lamp uses a odd 0.256″ DC barrel connector, but it does have a 12 VDC cigarette adapter that can be attached to the cord. Each lamp has an on/off switch. The vendor claims they can be rained on, but are not waterproof.
While I like the product concept very much (the carabiner, daisy chaining, power/light level), the units I have are suffering from a major technical issue; they aren’t meeting the manufacturer’s claimed specs of 0.26 amp current draw each (3.0 watts). My units are exactly half that at 0.13 amps (1.6 watts). Also, like many of the LED/CFL producers Goal Zero is playing fast and loose with the light level output, claiming one of their 3.0 watt lamps produces the same light output as a 40 watt incandescent lamp. The standard for a 40 watt lamp is 500 lumens — which is almost twice the lumen output of the 270 lumen Goal Zero lamp — in fact this is a lower lumen output than a 30 watt incandescent lamp.
It makes me wish I had an integrating photometer so I could see what the true output of this lamp is. Given the current draw is half spec, and the output is overstated by a factor of 2 as well, want to bet it is more like the output of a 15 watt lamp, instead? (A high-efficiency 1.5 watt LED produces about 120 lumens — the equivalent of a 15 watt incandescent lamp. Of curse it is still 1/10th the power consumption for the same amount of light — but the point is the actual output of the Light-a-Life is more like a 15 watt lamp, and nowhere close to a 40 watt lamp.
I’ve contacted the company about this issue and will edit the post once I find out what is going on. I have purchased a second lamp from a different source and found that it too consumes only 0.13 amps, or 1.5 watts — half the rating.
Light-A-Life 3 Watt LED Lamp
I ran across you article on the Light-a-Life and decided to measure the power draw from one of mine. It comes in at around 2.62 Watts (0.21 Amps at around 12.45V). Measured with a PWRcheck from West Mountain Radio. That seems closer to what the specs say. Did GOALZERO ever come up with a good explanation of why yours was low? I noticed that their webpage for this light no longer gives the 270 lumen rating (although the reference guide does still list the rating at 270 lumens). I’m curious if anyone has ever actually measured the light output from one of these.
Hi Steve,
I spoke with the company and they indicated that their lamp vendor had mistakenly shipped them the wrong lamps, about half the regular power. They offered to swap mine out, but I decided to keep them because they were bright enough and the lower power draw was a side-benefit. As for the lumen output that was based on their lamp vendor claims — wildly overstated for sure. Nevertheless it is still a useful lamp.