After last Halloween, my son suggested having light come from the road gutter drain outlets.
These are a nominal 5V device, but run well on a 3.7V Li-Po battery.
The LED was simply poked into the end of the connector. (longer leg of the LED to battery positive)
I measured the current draw of the LED to be in the 18mA – 30mA range as it changed colours.
Even though it hadn’t rained for a couple of days,
there was still water in the drain outlet.
I’ll have to give it a clean with the water blaster next time it’s out.
The neighbours probably think I’m a bit mad.
It gives off quite a bit of light.
I’ll have to check the drain with an inspection camera to see how far I
can put it back, while still being able to retrieve it at the end of the night.
Another option may be to drop a thin wire (or string first) down the house gutter pipe until it comes out of the road outlet.
Then I could power the lights from the house. This would also stop them getting flushed out if it rains on Halloween night.