Originally Posted by tinx
Yes, puck lights have a UV glass filter. Maybe the bottle glass reduces UV somewhat, it's certainly thick enough.
may have UV filters but I don't what a safe level of UV is. The intensity of sunlight?
The lamp maker knows.
The lamp pulls 4 A so a 40 Amp-Hour battery would give you 10 hours or less of runtime. The switch has to stand a 40 A surge for a few dozen milliseconds until the filament heats. It's a "tungsten load," slightly less stressful than a "motor load."
50 W distributed over the surface area of a Coke bottle should hardly warm it but the bulb may be designed to run in a free-air environment.