DogBoy

I saw a thread a long time ago about someone using a 9-volt battery with their NR taillight, but I can't find the thread anymore. Anyway, that gives me encouragement to try the following:

I want to ditch the super-long cable and get a 9-volt or AA battery pack so that I can mount the taillight at the end of my rack, and keep the battery pack just on top of the rack with some sort of quick-release. Do I need anything more than a small plastic case, some scissors, battery and electrical tape? I'm an electrical doofus, so here is my plan. Please let me know if you think this will work:

1. Buy 9-volt lithium battery
2. buy 9-volt adaptor (Radio Shack?)
3. Cut long wire of NR Light a little longer than I need it.
4. Strip insulation on wire, exposing 2 (I hope, with one of the red) internal wires.
5. Use 2 small electrical connection nuts to connect the 9-volt adapter to the light.
6. Tape it up all the way to the battery attachment point.
7. Find some kind of protective housing (any suggestions?)
8. Connect to bike. and ride.

So, will this work, and if so, will it also work in cold (0 degrees F for example)? How much burn time can I expect?

slvoid

https://www.bikeforums.net/showthread...der+tail+light

I just cut the end off the NR light and spliced it to a 9V adaptor. It's pretty easy, all you need to do is take the insulation off the 2 wires, braid the wires from the NR to the adaptor, then put a dab of solder on it, then wrap electrical tape around each wire to cover it up. Then wrap electrical tape around the whole thing.
OR, last month I took all that off and redid it, this time I put heat shrink tubing over the wires first, soldered it, slipped the heat shrink over the joints, and then shurnk it, makes for a really neat, strong, and professional looking job.
I also have a battery holder from radioshack that holds 8 AA's (2 on each side), you can get one that holds 8 AAA's if you want but the battery life is going to drop by about 4x compared to AA's. I get about 2 week's of 4 day a week commuting out of the 2500mah AA's, with AAA's, you get a much smaller battery pack but you'll have to recharge every 2-3 days if you use it a lot. A 9V would last you a day of commuting to and from work. The battery holders have a 9V type output, so you can either plug the 9V adapter from the light into the 9V battery or the battery holder.
If I were you, since nimh's don't last long in the cold, what I would do is try to insulate it. You can get these tiny chemical warmers for gloves and a small empty glass jar from like fruit jam or something. One warmer can last you a good 2 weeks, just pop it open and rubber band it to the battery pack to keep it warm inside a small pouch, then when ur at work, pop the warmer into the jar to turn it off.

DogBoy

Thanks for the link.
Edit: Nevermind...answered in your post.

2manybikes

What a great Idea, it must work for alkalines in the cold too, if done properly.

You should have brought it up ten years ago when I had all those alkaline powered lights.

Oh wait....you were 12 then.

slvoid

I probably could've told you that when I was 12.
Heh... my commute's only around 50 min in the dark in the winter and I've never had a problem getting 2 days use out of my headlights (high beam all the way with a little low beam in high traffic areas for extra visibility) when it's 10-15F outside.

jeff-o

Never ever use electrician's tape if you don't have to. Heat shrink all the way!

Other than that, yeah, I guess you rplan would work! You may want to figure out some way of waterproofing the battery though. Perhaps it could be stored in a rack bag or pannier?

EDIT: hmmm, I just reread this topic and realized the storage issue had been partly covered already. But here's a suggestion, find a project box (from radio shack or some other electronics parts store) that's big enough for the battery and maybe some insulation.

slvoid

Zip-lock bag with a piece of foam to insulate it.
Or you can buy one of those small insulating lunch bags, the plus side is, they're bright, easy to strap on top of your rack, relatively waterproof if you cover it with a ziplock, insulate from the cold, and its a good place to store your tool kit.

Anyway, here's what it looks like with heat shrink. Stupid me, I ran out of the really thin heat shrink, so I only had the big heat shrink for the big bundles. BTW, you'd want to make a piece of velcro with some rubber strips to pad the batteries if you're using AA's or going over rough pavement. My experience is that from all the bumping, at least one of the batteries will tend to pop out from the momentum of its own mass. I haven't tried AAA's but I guess they're light enough not to suffer from this.

DogBoy

Hmm...I'm starting to re-think. Since I already have the NR battery pack, I might as well just use it in a rack-trunk. The only problem with that is that the wire is still REALLY long....

I guess I have until October or so before I have to make up my mind...Thanks for the tips Slvoid!

2manybikes

Very nice.

Here's an idea I stole from the makers of my Lupine Edison. It works very well.

If you are going to heat shrink something that will be exposed to the weather or rain, before you shrink the tubing down put some rtv silicone seal inside the open shrink tube. Then as you shrink it down it squirts out the excess. Wipe it off quickly and you have a very, very, well sealed, cheap, and lightweight connection.

gear

I own four different tail lights and the NR one is by far the best. I was wondering how I might do just what you are doing (I even emailed NR and suggested they sell a model that way). Thanks for the unrequested info.

jeff-o

Excellent idea! I have also seen heat shrink with some sort of glue coating on the inside, which when heated (during shrinking) becomes a cort of gel-consistency. Everything gets sealed up tight with this stuff, though I don't know how easy it is to get off....