When I started grad school, I was a bike rider. Then winter came. Back in the Carter Administration the only reasonably priced, lightweight bike lights were “be seen” lights. They had a tiny incandescent bulb backed with a bit of reflective metal. You could see about three feet in front of you. They were good for walking home in the dark. They were powered (using the term loosely) by AA batteries than seemed to drain with each pedal stroke.
Bike lights were so useless that I became a runner. Seriously.
Many years later halogen lights came on the market. Dang were these awesome. They were much brighter. They were powered by a battery pack, originally the size and shape of a water bottle. If memory serves, these lights faded slowly as the power ran out. I used a NiteRider halogen light for many years, going through a couple of batteries in the process. They were a vast improvement. The batteries had an annoying habit of dying if you didn’t keep them charged.
Halogen lights have been supplanted by LED lights. These are smaller, charge faster, and are lighter weight. After my last halogen light died, I bought bought a Light and Motion Stella LED light. It had a small head lamp that I put on my helmet. The battery was the size of a deck of cards and was attached via a small cable. I loved the light but finding a place for the deck of cards was sometimes a problem. When I wasn’t wearing a vest or jacket, I’d stick it down the back of my pants. Eww.
The cord eventually broke and Light and Motion discontinued the Stella so I bought the closest substitute. This was similar in design except the cable now detached from the battery instead of from the light. And the battery was now an odd lumpy shape.
The cable on that light began to fray (it still works though after about eight years) so I bought an Urban 500, a different design. The light is in a tube that contains the battery. It can mount it on handlebars or helmet. Like the Stella, this baby puts out some serious light so you need to be mindful of blinding on-coming traffic on trails. Newer models are even more powerful. The all-in-one design means you can use them in camp at night or when the power goes out at home. Your family will love it when you burn their retinas out in the living room.
One advantage to this design is that you can take it off your helmet and mount it on the handlebars. I prefer helmet mounting because the light goes where my head and eyes are pointed. When the light is on your handlebars you can miss things like critters lurking near the trail. That said, these lights tend to have a narrow beam. I realized after riding until midnight in North Dakota in 2018 that I had absolutely no idea what I was riding past.
Here’s what this design looks like. This Rando model is very similar to the Urban 500. Specs on various Light and Motion lights vary. Some are brighter, charge faster, and such.
Recently, I bought the Vis 360 Pro which is a different design, intended for mounting on a helmet. The headlamp looks like the one on the Stella. It comes with a rear light (which contains the battery). The light works fine but I prefer the simplicity of the all-in-one tubular design.
The Vis 360 is intended to be left on your helmet. The Urban/Rando style lights can be removed quickly for safe keeping.
The only downside to LED lights that I have used is the fact that they go dark without much warning, instead of fading out like the halogen lights did. In any case, to my way of thinking, bike lights are the biggest improvement in cycling equipment in the last three decades. Most of my nighttime riding is to and from DC on unlit trails. Any of these Light and Motion lights is up to the task.
I have no idea what other manufacturers lights are like these days. If you shop around and wait for sales, you can get a high-quality headlight for under $100.