Electrical Question: How can I power a 6v lamp?

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EastOfEastLos

EastOfEastLos

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Hey all. I have a 6-8volt ollllllllld auto sealed beam lamp that I want to power discreetly. The back of the lamp has two terminals. Neither is marked positive or negative, they're just there. I tried four 1.5volt AA batteries in a parallel pack (side to side, flipping every other battery so one + would be next to the - of the next battery and so on. It looked like this: ||||. I had three bridge connections to make which I made with aluminum foil and electrical tape, + to -. I then wired the first positive battery end and the last negative battery end to their respective terminals on the back of the lamp. I got a very, very faint light to emit from inside the lamp. The batteries became very hot and I lost the little bit of faint dim light that the lamp produced.

I was trying to set up a AA battery system so I could hide the battery pack easily. A big 6v battery wouldn't be able to be hidden on my bike and I don't want to use an LED pack inside of the lamp housing because, first, It's a sealed beam and theres only a small, thin portion of the back of the lamp that is "unsilvered" and clear so it wouldn't let much light through there. And the dang lamp is so old and cool and apparently works judging from the dim light I got, I would like to use it the way it is.

Are there any electrical savvy fellow rat rodders out there who can point out the errors of my ways or point me to a vid or tutorial.
I looked for a tutorial here and googled a similar search but didn't find anything that worked.

-East
 
well... your sealed beam was probably meant for auto use, which means AA size batteries just dont have the current required to light the bulb. Even a square 6v battery wouldnt last very long.

so I hate to be the bearer of bad news... but it dont look like the lamp is gonna work for you. I know you dont want to run the big 6v battery due to not being able to hide it, and your against the LED thing.... BUT, what about if you were able to cleanly cut an opening at the back of the sealed beam so you could slip in a LED array out of a flashlight?

Maybe take the sealed beam down to the local glass shop and see if they can make a clean cut on the back of the bulb?
 
I know they make 6 volt generators to run off the tire, but I don't know if they would produce the wattage or amperage or whatever it is for the big sealed beam.
 
T.Y. Rat - I thought of that but, this sealed beam is at least about 70 years old and I couldn't bear to defile it (plus, I saw one NOS lamp, same as mine - GE 4012A going for $55 on ebay and it was just the lamp, no housing!!!, I got the lamp/housing for about $10 shipped.) Also, I'm old skool and want the old look, including the look of the light coming from the lamp so I wouldn't like the modern LED light look. I figured the AA idea was way underpowered.

I seem to remember someone here lighting their similar lamp with a battery pack. Can't recall who or which bike or how they did it.
 
Do you know how many watts the bulb is?

Since its an automotive type fog lamp, I bet it pulls at least 5 amps... thats enough to suck any battery down if ran for any length of time.

Not sure if modern Li-po batteries would work? I dont know a whole lot about them other than they pack a whole lot more current in a smaller package, and they can be quite expensive.
 
Years ago I rigged up a light using an old rechargable drill. I use one of those car roof top boxes for hauling skis and stuff. I forget what I used for a light but i had an old Makita drill, 6.2 volts. I cut off the handle (battery storage) and cleaned up the cut and wiring a bit. then mounted it up in the roof box. Easy enough to recharge when it ran low, just pull the battery and plug it in. You might be able to find a cheap rechargable tool at a pawn shop or consignment shop.
 
Ratfink1962 said:
Do you know how many watts the bulb is?

Since its an automotive type fog lamp, I bet it pulls at least 5 amps... thats enough to suck any battery down if ran for any length of time.

Not sure if modern Li-po batteries would work? I dont know a whole lot about them other than they pack a whole lot more current in a smaller package, and they can be quite expensive.
Click to expand...


It doesn't say on the back but from the info I've searched, signs are pointing to it being 35watts. Li-po / Li-ion? may be enough. I don't need it to light up other than for show. Maybe occasionally for a hour or so every once in a great while as I wouldn't and usually don't ride at night except for occasionally in the summer time when the nights are warm here in So Cal.
 
Walker said:
Years ago I rigged up a light using an old rechargable drill. I use one of those car roof top boxes for hauling skis and stuff. I forget what I used for a light but i had an old Makita drill, 6.2 volts. I cut off the handle (battery storage) and cleaned up the cut and wiring a bit. then mounted it up in the roof box. Easy enough to recharge when it ran low, just pull the battery and plug it in. You might be able to find a cheap rechargable tool at a pawn shop or consignment shop.
Click to expand...


You know, I have and old drill with the same voltage in the garage. hmmm. Wonder if it has enough life left to be recharged and would put out enough current to power the lamp... hmm.
 
35 watts at 6v = almost 6 amps :shock:

a rechargeable ni-cad pack might give you a little time. Im not sure if it would last an hour though.

Probably get the most out of a Li-po as far as current vs. physical size of the pack. do some searching for li-po discharge rates to get educated about them.
 
Im not fully educated about Li-po's but I believe they come in many different configurations, even single cells if you want to build your own packs.

One thing I have heard is that while they are very capable of high current discharge, they are NOT very forgiving when it comes to charging, make one mistake and you have a good chance on killing the battery.

Im also assuming you would need to build a cutoff circuit so you dont accidentally over discharge it. No big deal when you do that with Ni-cd's but Ive heard thats another thing that kills Li-po's.
 
Been reading about the Li-Po's. They seem a bit volatile if you make a mistake. Especially to try to make a series or parallel pack out of them and then expect to be able to recharge them safely. I think I might be open to other options. I have some semi new AA 2500mah NiMh rechargeables. Only thing is they're 1.2v each. But I'm thinking even if I totaled the 6v, it still might not be enough juice even with these. :?:
 
Basic battery stuff...

You can always stack them to get the voltage you need.

+HHH- +HHH- +HHH- +HHH- +HHH- <-- 5 (1.2v) cells stacked in series = 6v

And depending on the current rating of the cells (MaH) you can stack more sticks in parallel to get a higher current output.

like this....

+HHH- +HHH- +HHH- +HHH- +HHH-
+HHH- +HHH- +HHH- +HHH- +HHH-
+HHH- +HHH- +HHH- +HHH- +HHH-

still 6v total, but current would be x3 (500 MaH sticks x3 would equal 1500 MaH total)
 
deven_science said:
If you're hard up for ideas, put a generator on each wheel, and wire them in parallel so that you're doubling the amperage that's going to the light. :)
Click to expand...

That would also probably work.


Anybody recall somebody here doing a similar job on their bike? I do, but can't remember when or who it was. It came out well if I recall correctly.
 
Ratfink1962 said:
Basic battery stuff...

You can always stack them to get the voltage you need.

+HHH- +HHH- +HHH- +HHH- +HHH- <-- 5 (1.2v) cells stacked in series = 6v

And depending on the current rating of the cells (MaH) you can stack more sticks in parallel to get a higher current output.

like this....

+HHH- +HHH- +HHH- +HHH- +HHH-
+HHH- +HHH- +HHH- +HHH- +HHH-
+HHH- +HHH- +HHH- +HHH- +HHH-

still 6v total, but current would be x3 (500 MaH sticks x3 would equal 1500 MaH total)
Click to expand...

Thank you Mr. Ratfink1962, I really appreciate all the info you've contributed so far!!!!
 
Lights for 'show'....
If you are doing a static display use a big 6V in a cooler to hide it and a couple of frame routed wires with a quick disconnect down low to hook it up.
 
gcrank1 said:
Lights for 'show'....
If you are doing a static display use a big 6V in a cooler to hide it and a couple of frame routed wires with a quick disconnect down low to hook it up.
Click to expand...
Well, actually to clarify, I meant for "showing off". Like when someone will ask "hey, does that light work?"...I can then flip a switch and hear the ooh's and ahh's. Or for the occasional twilite ride in the summertime. Not for "showing" the bike like at a "bike show". :wink: :wink:
 

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