Six years ago I bought a Princeton Tech Switchback 3 headlight system with a Lithium Battery for trail riding at night. I used the setup on and off for several years, mostly during hunting season where it’s not safe to ride here in the daytime. You can tell the first day of hunting season out here in the country because it sounds like a war has started with the constant stream of gunfire. Welcome to America.
When I got into ebikes it didn’t make a lot of sense to lug around an extra 826 Grams with the 11 cell LIthium pack I started looking for options that would plug into my existing ebike battery. I was quite happy with as the Switchback 3 as it lasted about 6 hours on high and much longer on med and low light modes. It also had lots of accessories and worked well both on the handlebars and mounted on my helmet.
I spent a lot of time looking for the ‘perfect’ ebike light on Ebay. The one I ended up buying was $10.42 shipped and works with any voltage from 12v up to 85v without any voltage converter installed. You can find one similar to what I bought from ebay here. I crimped Anderson Powerpole connectors onto the end of it and then hook it up to the charging cables directly onto the battery. Since this headlight has very little power draw the smaller gage wires of the charging connections work perfectly for the headlight and that means I can use the headlight and the ebike motor at the same time without having to build a Y cable for it. It is unwise to hook an unfused light to your ebike unless your battery pack has built-in short protection.
I tested the switchback 3 against the ebay light and I can say that the ebay light got a lot hotter. How hot? Too hot to hold. Luckily there is a built-in thermostat so when the light starts getting to the temps that will probably burn your house down the light shuts off till you cycle the power on it.
The light on the ebay led was more direct than the Switchback 3 and it was also about twice as bright. It was certainly bright enough to make you see spots, but not quite bright enough to destroy your vision forever. The light does not overheat as long as you are moving along at around 5 mph or more and don’t stop for more than about 10 minutes in one place without moving. The entire thing is basically one big heatsync.
Although comparing these two lighting systems is pretty unfair as one ships with a fancy battery and the other one has just bare wires from China, it does show how overpriced many American bicycle goods are. The Switchback 3 served me well for many years, but I will never buy a headlight that expensive again when there are so many cheaper options available. At $10.42 it makes sense to buy two so you can be twice as safe and really look like an actual car at night (one with headlights that are really close together).
Just don’t wear them on your helmet and look directly at the drivers, these lights are bright enough to seriously blind them.