Emergency Solar Christmas Lights

Old School Tech has posted an article about converting Christmas LED light strings into emergency DC lighting for use directly from an off-grid battery array, no inverter required. This kind of lighting is great for safety-critical areas and allows a reliable backup source of lighting when other sources fail. Annoying AC flicker is also eliminated. The linked article also discusses issues relevant to increasing the lifetime of the lights.

In addition to safety lighting, your imagination is the limit when it comes to sprinkling low-voltage and low-current lighting around. Although the article discusses cool white lights, warm white and multicolor lights are also available. For an operations center needing to protect night vision (the eyeball variety), red lights would be a perfect choice. Red lights or warm white lights are also great for remote illumination for night vision devices. If remote illumination isn’t desired, blue lights could be used. Blue lights will also make it harder to detect an installation by an adversary using night vision devices.

The cool white Christmas LED lights, with an internal current-limiting resistor, are not terribly energy efficient in LED terms, but are still very energy efficient compared to other lighting technologies. Accordingly, they barely show up in a close-up thermograph, as shown below, even with the field of view restricted to allow the auto-ranging feature to pluck them out of the background:

The large boxes in the background are the batteries themselves. The inverter on the other side of the batteries is a bright orange box in comparison.

Finally, the article discusses the use of cheap Cat3 cabling to run lights at a distance. In a future article, we’ll show some interesting things you can do with this fact around the homestead. Also note that only a single pair of the four available in the Cat3 is needed to efficiently and remotely operate several DC strings, defined as six to eight lights each. This leaves the other pairs available for other purposes, such as operating field phone remotes.

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