newbie questions on Mag 4D Hotwire.

[rizky_p]

I am building M@g Hotwire mod using Mag 4D, i am planing to use 12v 35w 2000 hours/~2950K rated halogen bi-pin bulb. What is the best battery to use for this setup? i have one in mind using 12 Sanyo 2700, will it hold the voltage at such load to everdrive the bulb?
I know i should have used CPB or at least enloop but i have plenty new sanyo 2700 around and use it instead to keep the cost to minimum.
How about AW's 17500 lithium 4S2P configuration? is it good alternative?
What is the pros and cons between 6v and 12v halogen bulb? should i use 6v bulb instead since it will require less cells therefore cheaper? But all 6V bi-pin i found have vertial filament which looks realy weird on my reflector.

I cant get any exotic lamps such as WAs so i have to stick with common halogen bi-pin.

FYI.
I am using unbored 4D body
Kiu High temp socket kit.
no resistance fix applied to any parts of the mag.
no battery adapter, i will solder all the batteries and make it into pack.

Many thanks.
Rizki P.

 

[RoyJ]

The Sanyos would be a very good choice. The bulb would draw 3 amps at spec, a bit more (probably 3.4 or so) at the overdriven voltage (14.4).

If I remember correctly from the battery shootout, the Sanyo 2700s would hold approximately 1.15V under a 3amp draw. Since you're soldering the pack, the resistence would be minimal. You could do a swithch and tailspring mod if you find the light is still not bright enough.

At this wattage, I'd definitely stay 12V rather than 6v, or you'll be looking at much more exotic cells due to double the amperage. Although you could put 6 sub-Cs in there and drive a 6V 35watt bulb. I don't see the point, since you're not gaining any size, brightness, or runtime advantage. Plus the bulbs will be harder to find.

I don't know if the level of overdrive is enough to make the bulb bright, or white enough for your tastes though. FYI I'm building a 6V, 20watt setup, but overdriving it with 8 cells @ 9.0V aprrox. But I'm using a 5000 hr bulb.

You can try re-wrapping your cells with clear packing tape, and then fit 13 or even 14 cells for approx 16V under load. This would be a good amount of overdrive for a 2000 hr bulb, giving you well above 1000 lm.

 

[mdocod]

under the load and resistance you'll probably get about 13-14v at the bulb, which isn't going to be enough to make the bulb exciting. You need to get ~18V to a 2000 hour 12V bulb to make it worth your while.

 

[rizky_p]

under the load and resistance you'll probably get about 13-14v at the bulb, which isn't going to be enough to make the bulb exciting. You need to get ~18V to a 2000 hour 12V bulb to make it worth your while.

thanks i guess i will have to figure a way to squeeze more batteries into the mag...
Any suggestion on achieving more voltage? Mag 6D probably the easiest

 

[rizky_p]

The Sanyos would be a very good choice. The bulb would draw 3 amps at spec, a bit more (probably 3.4 or so) at the overdriven voltage (14.4).

If I remember correctly from the battery shootout, the Sanyo 2700s would hold approximately 1.15V under a 3amp draw. Since you're soldering the pack, the resistence would be minimal. You could do a swithch and tailspring mod if you find the light is still not bright enough.

At this wattage, I'd definitely stay 12V rather than 6v, or you'll be looking at much more exotic cells due to double the amperage. Although you could put 6 sub-Cs in there and drive a 6V 35watt bulb. I don't see the point, since you're not gaining any size, brightness, or runtime advantage. Plus the bulbs will be harder to find.

I don't know if the level of overdrive is enough to make the bulb bright, or white enough for your tastes though. FYI I'm building a 6V, 20watt setup, but overdriving it with 8 cells @ 9.0V aprrox. But I'm using a 5000 hr bulb.

You can try re-wrapping your cells with clear packing tape, and then fit 13 or even 14 cells for approx 16V under load. This would be a good amount of overdrive for a 2000 hr bulb, giving you well above 1000 lm.

yeah the good think about 6v is the overdrive voltage is relatively easier to reach but require more robust batteries and more expensive bulbs...

i'll see how it will endup with my 12 sanyos...if it isnt bright or white enough(which probably wont) i might bore the tube and use more sanyo or buy 4S2P AWs 17500 but still not high enough to excite the 12v bulb maybe 5S2P Aw's 17500 but this it too much for me/bbulb as it will now require a soft start or

man! this mod turns into money sucking devil!! :devil:
well at least i enjoyed it! :twothumbs:

thanks.

woohoo 500 posts and i am officialy a flashaholic with STAR!!!

 

[RoyJ]

Like I mentioned previously, the easiest way to squeeze out more voltage would be to re-wrap the AAs so you can fit 4-across on ANY STOCK MAG.

Once you've re-wrapped them, just solder 4 in series into a long chain, and make 4 of these chains in total, but the last chain having only 3 cells. This would be 15 cells giving you 18V like mdocod suggested.

Then, make sure you hot glue them all together, with all the batts touching eachother (absolutely no gap), and complete soldering the connections. There, you've got yourself 18V that fit neatly into a 4D.

 

[rizky_p]

Like I mentioned previously, the easiest way to squeeze out more voltage would be to re-wrap the AAs so you can fit 4-across on ANY STOCK MAG.

Once you've re-wrapped them, just solder 4 in series into a long chain, and make 4 of these chains in total, but the last chain having only 3 cells. This would be 15 cells giving you 18V like mdocod suggested.

Then, make sure you hot glue them all together, with all the batts touching eachother (absolutely no gap), and complete soldering the connections. There, you've got yourself 18V that fit neatly into a 4D.

i just got the 4D tube bore out today at local CNC workshop, now i can fit 4 sanyo across without removing plastic wrap. cant wait to test it