"That's the brightest tail light I've ever seen"

[Charly Banana]

That's what a fellow bicyclist said to me today when he stopped to talk to me. I had passed him resting on the side of the road on my way home. As I walked to check the mail at my mailbox he caught up with me. He stopped to inquire about where did I get such a bright tail light. He told me that as I passed him, he could see my tail light a half a mile away in the brightest sunlight.

I got thinking that if he wanted to know about my tail light, maybe some DIY person on this forum might also be interested. So, I took some pictures of the light at 1PM with the sun at it's brightest without any clouds in the sky. The bike is sitting in full sun. Unfortunately, it's hard to catch the full effect of a bright light with a camera, but the photos will give you an idea.

For a comparison, the typical bicycle tail light is about 25 lumens brightness. Even the Light and Motion Vis 180 Tail Light which is one of the brightest is only 50 lumens. This light I'm using is 190 lumens. This is in the same category as DiNotte 300R RED Taillight which is 150 lumens.

I power it with 10 AA Nickel-Metal Hydride batteries which gives 12v. I use one of the 10 cell plastic battery holders you get on ebay. I keep the battery pack in my trunk bag small right hand pocket. The connectors I used are the standard 12v connectors you get with 12v wall chargers. You can see the connectors in the close up photos. I charge it with a Tenergy Universal Smart Charger for NiMH/NiCd Battery Packs (6V - 12V). The 4 Watt Vehicle Mini Strobe Lighthead itself I got here. The light has some pretty neat strobe patterns, but I use the steady on - off flash so as to not be too offensive to the drivers.

 

[Admin]

That's pretty intense! How much extra do you think this light weighs with those 10 AA batteries? I like the saddle bag you're using with the rack and the light is awesome. How long do the batteries last and are they rechargeable or not?

 

[Charly Banana]

I have no idea of what the batteries weigh, my digital bathroom scale says 0.5LB, but that's the lowest reading it can give. The light draws 210mA at steady on and the batteries are 2000mAh , so the batteries will last about 10 hr. Since I use the flash mode, it should last a lot longer. With my battery holder setup I can charge the batteries as a group with a 12v charger or each cell individually if I want to balance all the cells. After my typical 1 - 2 hr ride it takes about 15 -30 to charge back up.

 

[Admin]

I have no idea of what the batteries weigh, my digital bathroom scale says 0.5LB, but that's the lowest reading it can give. The light draws 210mA at steady on and the batteries are 2000mAh , so the batteries will last about 10 hr. Since I use the flash mode, it should last a lot longer. With my battery holder setup I can charge the batteries as a group with a 12v charger or each cell individually if I want to balance all the cells. After my typical 1 - 2 hr ride it takes about 15 -30 to charge back up.

That's awesome! Glad to hear you're using rechargeable cells, sounds like a great setup and that added safety is priceless