Bike blinkie re-wire

[MMACH 5]

I've searched the forum, but haven't found anyone who has modded LED blinkies as I am wanting to.

I commute to work on my bicycle. The route I take puts me on fairly major streets for 35+ miles so the more visible I am, the better. I run three 9-LED blinkies on the back of my bike. They line up across the back of my rack, with the outside blinkies set to constant light and the middle one set on flashing.
They each use 2-AAA batteries and I'm using rechargdables, which I charge up twice a week.

I have a RadioShack, 9.6v, 1000mAh, Ni-Cd rechargeable battery pack and I would like to run all three lights off of this pack. So here are my questions:
a) Can I simply connect wires from all three lights into a "main" wire which will plug into the battery pack? I'm concerned that I would run the risk of frying one or more of the blinkies since I can't turn them all on simultaneously.
b) Is the extra .6 volts in this battery pack going to be an issue for these lights to handle?

Thanks
MMACH 5

 

[frenzee]

I don't know about your specific battery, but most 9Vs are made up of 6 AAAs, so it's six or a half dozen...literally.

http://www.instructables.com/id/SVP8JMYF9N29YDE/

 

[chimo]

I think you will find the cells in certain 9V batteries are AAAAs.

I don't know about your specific battery, but most 9Vs are made up of 6 AAAs, so it's six or a half dozen...literally.

http://www.instructables.com/id/SVP8JMYF9N29YDE/

For the OP, I think you would be better off getting a couple of high capacity C or D NiMH cells (5000-10,000 mAh), put them in series and run the blinkies in parallel off of that pack.

 

[Brlux]

You can't put them is series or parallel with a 9.6V battery. If you had a switching power supply that could drop the 9.6V to ~3V than you could hook them all up all the lights to it in parallel. Perhaps a better solution could be to get a 2AA battery holder and hook it up to all the lights in parallel. this would only require the changing/charging of one set of batteries and it would be a lot more convenient then having to take all the lights apart to change the batteries. A AA has about 3 times the capacity of a AAA so your 2AA setup should run about as long as your current 6AAA setup.

 

[MMACH 5]

Actually, this battery is made up of what looks like 8-AAs.
http://www.batteries-online.co.uk/d/batteries_Hobby%20Batteries_xxnonexx_xxnonexx_14909.htm

Only having to pop out a couple of batteries would be easier than my current setup. Not to mention less wear and tear on the lights' housings.

If I go with the two-AA-battery setup, I could run the wires from an old flashlight body to keep them waterproof. (I just thought of this while I was typing the previous paragraph).

Hmmmm. I've got some soldering to do...
I'll let y'all know how it goes.

Thanks for all the replies. :thumbsup:

 

[Brlux]

Ya it is 8AA but they are all connected in series giving a voltage far to high for your intended application.

 

[MMACH 5]

So, I finally got around to testing this setup.
I've done scads of mechanical modifications and home-builds on my bikes, but this is the first electrical modification I've done. As such, I was a little leery about the setup, (Brlux, don't take it personally. It's just my own ignorance playing into things).

So, instead of jumping right in with the $45 in tail lights from my bike, I decided to test this on several old AAA, LED blinkies. For now, I've been making most of the connections with alligator clips. Tonight, I'll get down to business with the soldering iron.

I'm using 18G wire, just because that's what I had on hand, and four splitters. I wired the buggers together and yes, 2-AA batteries in a parallel circuit does power all three blinkies -- woot!
Yes, I'm felt a welling of pride in making this work and you must be thinking, "Jeez, this is pretty simple. What a noob."

Anyway, here is my one issue:
When I have one or two of the lights set to blink, the remaining light, (set to constant), dims with each flash of the other two. It is less noticeable when the batteries are fresh, but still apparent. Is there a way around this, or is this just the nature of running these off a parallel circuit?

Thanks again for all the help.

 

[znomit]

The current drain on the batteries causes the voltage to drop during the blinkies flash, hence the other light dims.
The main benefit of running 3 lights is that when one goes out the other two will still be going. Now you just have one big light.
How about getting a 4AA battery pack and running the blinkies of 2AAs and the steady off the other two?

 

[MMACH 5]

I'd like to stick with the 2-AA setup, if possible.

Tell me if I'm getting in over my head, but what about wiring in resistors to control the power fluctuation? Or do resistors not work that way?

Thanks again.

 

[MMACH 5]

Okay, so I've been googling and wondering if a 'bridge rectifier' would stabilize the power going out the the three lights.

Oh yea, and what is a bridge rectifier?

 

[MMACH 5]

I feel like an ig now. I was setting two lights to flashing which produced the dimming effect on the one remaining light. State law says you can only have one flashing light visible on the rear of a vehicle unless they flash in unison. This setup is reserved for emergency vehicles.

When I set two lights on constant and only one to flash, the dimming is so slight that it is not even noticeable.

When I get everything soldered and put on the bike, I'll post some pics.

Thanks again for all the help and for not beating me up for my ignorance.

 

[Doh!Nut]

Hi MMAC

If you have a look in the beyond flashlights/transportation/bikes section there are lots of front lights and at least a review of a tail light.

I got some 14000 mcd LEDs from besthongkong.com and replaced the stock LED, made a worthwhile improvement.

If you have a rack you have a great mounting point for a home brew light.
I would suggest a red cree from DealExtreme and a micropuck from LEDSupply.

Nick

 

[MMACH 5]

Woot!
I got it all hooked up and am very pleased with the results! I used plumber's silicone to seal up the wires' entry holes. The only thing I'm going to change is the velcro straps. I think elastic cords will hold the flashlight, (battery container) in place a little better.

I was telling a co-worker about about my plan and he said he couldn't imagine three lights running from 2-AAs being as bright as one light running from 2-AAAs. So, I decided to do some comparison shots.
I got out my mountain bike which has the same light as my commuter. However, it is a single light. I made sure they were both running from freshly charged batteries and here's what I got:

I really like the last one. It really shows how much more light is being thrown back with the triple setup.
This has got me thinking about tinkering with my headlights now. I'm going to post over in the Transportation Lighting/Bicycle forum with my plans on this.
(I think y'all got me hooked!)
Thanks again. I couldn't have made this upgrade without everyone's help.