Cheap light for buildngs, cars, etc.

Update on the battery test, 3.5-4 hrs on dollar store batteries

The modern version of those lights (often called "fairy lights") use very tiny LEDs, and will run for 48 hours on a battery. Not much more expensive than the garage sale:

https://www.amazon.com/dp/B07M639F8T

good info avanti, thanks

Why use batteries when you can use a wall wart? An extension cord is not needed, just a length of 24 gauge 2-conductor wire.

Probably because I have no idea what your talking about......

"Wall wart" is slang for those ubiquitous black plastic cubes the have the prongs to plug into the wall out let and provide low voltage AC or DC for small applicances, chargers and etc. Most folks have a bunch of them lying around from dead electronics. As you're using incandescent bulbs you wouldn't need to worry about AC/DC but assuming your batteries are wired in series about 3 volts. Check you junk drawers, the wall warts are usually marked.

You would need to cut of the plug and splice the wires to the wires on your lights, with bulbs no need to worry about polarity.

Thanks for the info everyone. I guess my whole point was that these did not need a wire to an outlet.

@beardog49 posted:

Thanks for the info everyone. I guess my whole point was that these did not need a wire to an outlet.

Certainly true, but they do require frequent battery changes.  If you use them much, or forget to turn them off, it can get expensive.  Everything has tradeoffs.

@beardog49 posted:

I picked these up today at a yard sale for .50 ea.  4.5 foot string, 10 lights, operate on two C batteries. Currently testing to see how long they will last on dollar store batteries. Should have some use in places where you can't run an extension cord. Also I bought a set of colored markers at Micheals and found you can color these.

John

FWIW, between Sept and the 2nd week of Dec, I goto Michaels with 20% off coupon and get the led ones. The leds are smaller, come in various sizes [3mm, smd,5mm,etc.] On strings of ten and have the barrel plug for wallwart option.

Ask Allen G. how well they work!

For the past umteen years I have been using old computer transformers stripped from computers and for the price of $10-$20 used they provide constant DC voltage of 3V, 5V, and 12V and that in conjunction with resistor (if needed) could power anything on your layout.  There are many instructions on the Internet on jumping the wires to make them run without a computer.  Basically just the right 2 wires soldered together and then when you switch on the AC voltage your power is on and converted to a pure DC voltage which in my opinion is much better than AC.  I have used it to power miniature Xmas tree bulbs in building as well as quite a few LED lights.  Most of these transformers are rated 600 watts or better.  I have powered about 100+ buildings and street lights  using 2 transformers and never had to replace a street light bulb or any bulbs for that matter.  When adding light to buildings the intensity of individual lights weather it be incandescent or LED can be varied by adding small resistors to each bulb so all the lights in a building don't have to be the same brightness.

If I may,

So you run wires from the buildings to the DC transformer. (and I'm constantly throwing away USB C transformers so I'm sure I could find some). How do you wire it to the building that is meant to run on AA or AAA batteries? Solder wire to the two ends?