Mag 5C w/NiMH and 6V bulb

Ok, I poked around a little and did a search on Mag 5C, so I might have missed a prior post on this subject, but I'd love to try a Mag 5C light with 5 4500 mAh NiMH C cells installed and a 6V bulb with a high current rating (say 1.2 amps or more). Anyone tried this obvious configuration?

I suppose this would be an ok configuration if the reflector doesn't melt...
I'm not sure how much the voltage would drop on C size 4500 mAh NiMH cells under a 1200 mAh load... guessing an output of 1.05 - 1.10 Volts per cell once the initial peak is lost at the beginning of use?

Should this configuration be pretty bright, perhaps at or above UltraStinger levels? With the right bulb I'm guessing it'd have to be except for the darn crappy Mag reflector....

Thoughts?

- Brian

(This might be considered a mod I guess. Please move this there if so.)

The Mag Reflector is made of Polycarbonate that Mag says is stable to 320 degrees F.

I run a Mag 2D with 2@ 3AA 1800 mAh NiMH packs totaling a nominal 7.2 V. I use a Carley 6.0 V 1.7A Krypton Star rated at 14.5 SCP = 179 Lumens. These 6 cells are probably voltage dropping to around 6.5 Volts, and the overdriven Krypton bulb hasn't blown yet.

I run a Brinkmann 5 D cell light with a special ordered #851 Carley Halogen T-2 1/2 bulb potted into a ceramic potted PR base. This bulb is rated at 6.0 V 1.70 A 10.2 W 20 SCP = 247 Lumens. Your C NiMHs would probably voltage drop to 5.7 to 5.8 Volts to slighlty underdrive this bulb. The underdriving will extend the 20 hour rated life of the bulb. The 5.0 AH D NiCads I drive this bulb with experience less voltage drop than will the C NiMHs. I would certainly use it in your application.

I have not yet heard of a Mag C or D light Reflector being destroyed by a 10W bulb.

Halogens work on the halogen cycle and without the proper temperature, it will not function properlly. So under-driving it too much may in fact decrease the life of a halogen bulb

Nerd:

It's my understanding that underdriving a Halogen bulb 5 to 10% under design voltage will not defeat the halogen cycle. Some greater percentage underdrive is necessary, as I understand it.

lemlux, that's good news about the temperature rating of the reflector. I thought I had read about others here melting their Mag reflectors. I don't think it will be a problem, then.

Nerd brings up a good point about the halogen cycle. I think I'd rather overdrive than underdrive since I want an extremely bright light. Bulb life will be shorter, but I think I can live with that.

This is all just hypothetical right now.. I don't actually have a 5C Mag nor 5 NiMH cells to play with. Since NiMH's have a higher internal resistance, maybe NiCds are the way to go. Even a 2.4 Ah C cell would give good runtime I think.

Are there any higher current bulbs than the Carley 1.7Amp?

- Brian

Something I read on another website had some statistics about light output vs input voltage. This was in reference to halogen car headlights which normally have a voltage rating of 13.5 Volts (the voltage that the alternator puts out):

"At this voltage (13.5V), halogen headlamp bulbs achieve 100 percent of their design luminous output. When operating voltage drops to 95 percent (12.825v), headlamp bulbs produce only 83 percent of their rated light output. When voltage drops to 90 percent (12.15v), bulb output is only 67 percent of what it should be. And when voltage drops to 85 percent (11.475v), bulb output is a paltry 53 percent of normal! [Source: Hella KG Hueck AG, Germany]."

At least for car headlights, input voltage is important for light output. It's probably very similar in halogen flashlight bulbs too.

- Brian

bmsmith: I remember seeing a halogen 6v 3.3 amps bulb on carley's web site.

Lemlux: 6 volts at 10% underdriving is 5.4 volts.

Couple that with voltage dropping after a high current draw.... I don't think it will exceed 5 volts. As such, the lamp won't be driven efficient on a watt/lumens..

correct me if I am wrong.

I have found that a 3.3 Amp bulb will drop a 1/2 D NiCad battery to fairly steady 1.1 V per cell.

I have found that 4500 mAh NiMH C cells will drop fairly rapidly and steadily from a starting point around 1.1 A per cell.

I have two High output (20 Amp) 3000 mAh NiMH Sub C RC battery packs that are specced to stay at close to 1.1 A for much of their run time at 20Amps. I'm toying with various ideas of what I could do with 3.3 A bulbs and a dissassembled battery pack. The Mag Polycarbonate reflector isn't in those plans.

LemLux: Can you reveal where you can get your 4500 NiMH C cells?

lemlux, yea that reflector is pretty terrible, isn't it? Hmm, it's probably not worth my money to even bother. I just looked at my 3D Mag and it's pitiful with the rings and non-circular shape. A high output pitiful beam is a still pitiful beam.

I want to know what flashlight Ed Norton was using in Red Dragon which I just saw tonight. It looked like a 4D or maybe even 5D Mag, but the focal spot it threw on the walls was incredibly uniform and circular. I wonder if the lens was coated with that PDA protectant covering stuff to diffuse the beam?

Nerd: Try this link for 4500 mAh C cells: http://www.sunnbattery.com/item.jhtml?UCIDs=553828%7C819726&PRID=859410
Since it might be tagged with a unique cookie ID number or something it might not work, but they have them. They also have 8500 mAh D cells.
Thanks for the Carley bulb info.

Maybe a 6D Mag with a 6V bulb might be a better bet all around, but that's too bulky.

- Brian

6 D = 9 volts. Overdriving a 6 volts bulb to 9 volts is extremely risk? Don't think many bulbs can take that for long. Might even instantly burn out.

bmsmith:

Why not use 3 AA cells in a D cell size package and stack two of em up in series and another 2 up in parallel to get a 9 volts 4D size package with around a max 4 amp hour package?

Originally posted by lemlux:

I have two High output (20 Amp) 3000 mAh NiMH Sub C RC battery packs that are specced to stay at close to 1.1 A for much of their run time at 20Amps.

Click to expand...

<font size="2" face="Verdana, Arial">Lemlux,
Do you mean 20Amp, 3000mAh, NiCAD Sub C?
I've never heard of a NiMH that could handle such a high current.

Thanks.

Originally posted by lemlux:

I have two High output (20 Amp) 3000 mAh NiMH Sub C RC battery packs that are specced to stay at close to 1.1 A for much of their run time at 20Amps.

Click to expand...

<font size="2" face="Verdana, Arial">Lemlux,
Do you mean 20Amp, 3000mAh, NiCAD Sub C?
I've never heard of a NiMH that could handle such a high current.

Thanks.

For many years I have used a Magcharger 6V battery pack (5 1/2 D NiCads, 2.2AH) in a regular Mag 3 D light (exact same size) using a a halogen 5.2V 0.85A lamp.

My idea was to get substantially brighter light than a 3 D cell Maglight, and longer burn time than a Magcharger.

And in that regard, it does succeed, in that I get around 2 1/2 hour burn time.

This was my very first mod, using the lamp that was at the time standard in an Energizer 6V Halogen Lantern. This configuration now lives in a silver 3 D cell Maglite, and is a light I like to use for rough duty, when I don't want to beat up my Magcharger, or want more run time, and size and weight aren't a factor.

I mainly bring it up for the Magcharger battery pack, which is a fairly usefull size and capacity.

Of course, it helps if you have a Magcharger to charge it up; but I'm sure it can easily be done with another 6 volt charger.

Nerd, I meant a 6D Mag with 6 NiMh batteries, which would be around 6.6 V under load - a moderate overvoltage for a 6 V bulb.

kenshiro, I think lemlux is talking about the Panasonic (and others) NiMH cells that R/C companies like Trinity ( http://www.teamtrinity.com/batts/matched.asp , and click on the "label" link in the text for label info) sell as packs or as single cells for making your own packs. These cells are tested and labeled with the cell's performance under load (up to 30 Amp discharge rate). New 3300 mAh cells are out now from Sanyo as well.

Gandalf, that's a good mod. Thanks for the idea. I even have one of those black Eveready Halogen lanterns. I love it. The beam is great.

- Brian

bmsmith:

Thanks for answering kenshiro's question. I think Panasonic was the first to the market. Sanyo's cells are well regarded, and others are probably worth haveing also. I didn't realize that 3300 mAh Sub C's are now available. Wow!

Kenshiro:

FWIW the highest capacity NiCad Sub C's I've seen are 2400 mAh. By comparison, Surefire and Streamlight haven't chosen to market anything better than 1800 mAh in their rechargeable packs.

Nerd:

Sorry, I don't have the link on my home computer, but I think I bought the C cells at a site like Thomas or OnlyBatteries. I got 6 no-name 4500 mAh green labeled NiMHs for about $38. If you search you'll find them. This site shows pictures of the packages of a very wide range of rechargeables.

The Eveready lanterns used an HPR36, which I think is 5.4V at 1A. I like them too, as one was my first flashlight better than a cheapo 2D.

I wonder why halogen small bulbs are now relegated only to bicycle headlamps. All the lanterns now are krypton bulb using.

radellaf,

I think my Eveready was my first "good" lantern/flashlight I ever got as well. That's funny! You made me curious, so I opened my Eveready lantern to see what bulb it has. It reads:
on line 1: "Philips Belgium"
on line 2: "5.5V 1A HMP 15 K4"

The bulb is one of those PR based ones with the tubular look and flat top with a small glass point in the top-middle. The filament is quite straight across rather than in an arc. It's what I call a "typical halogen bulb" type of look, which means absolutely nothing in the real world, but what I attribute to what a lantern halogen bulb looks like.

lemlux: I hoped it was ok to speak for you regarding the NiMH cells. As I recall, the first 3000 NiMH cells for RC use were the Panasonics, with mixed results in field testing. Some racers didn't like the new cells and said they lacked "punch". Proabably they were seeing the results of the higher internal cell resistance. Then I think the Sanyo NiMH's came out but weren't quite as good as the Pana's by most accounts. I believe Panasonic refined their cells and lowered the internal resistance as time went on. The NiCd world was still using the RC2000's. Then the RC2400's (NiCD) came out from Sanyo first (I think?) and then the 3300 NiMH's from Panasonic are pretty recent. Now it looks like Trinity has Gold Peak (GP) brand as well. I'm not into RC cars as much as I was, but still subscribe to RC Car Action to try to keep up on current technology. I really wish Streamlight would team up with Trinity and make some awesome RC2400 NiCd packs for the Stinger/Ultrastinger series of lights.

- Brian

Carley _Private labels a 5.0 V 1.25 A HPR lamp for Ikelite that can be bought at some dive shops for around $8.

bsmith: You know far more about R/C than I do. I just figured that anything designed to put out 20 A should do fine with any lamp in the 3 to 5 Amp range. My thanks were sincere, not sarcastic if thats what you fear.