A good UV flashlight is only as reliable as the battery powering it. For 365nm lights using rechargeable 18650 or RCR123 cells, the battery affects runtime, output, reliability, and safety. The biggest rule is simple: don't buy lithium batteries based on the biggest...
This question always comes up when we're traveling to some far off, glorious glow rock haven. Luckily, the FAA has published rules that are easy to understand - covers lithium batteries, lead acid, and all other batteries. Generally speaking, the answer is yes, when...