Practical Guide to using LuxLuthor's Destructive Tests - 64458 example

[LuxLuthor]

In answering this PM, I thought it may be of use to post information here as a topic. Feel free to comment.

I want to build the brightest setup in 3D tri-bored Mag. I study your thread destructive incan bulb test...
my specification:

- HAIII 3D Mag tribored by Delghi
- 3" HAIII head by Delghi
- smooth reflector
- AW soft starter
- bulb: 90W Osram 64458-S
- mod. tail cap spring
- 19.2V - 24V NiMh Smart Charger

now my question: what is the "maximum" battery pack for my setup? Or exists for a 3D Mag a brighter setup? :thinking:

19.2V (16 cells) $78
20.4V (17 cells) $81
21.6V (18 cells) $84
​

I saw in your thread the 64458 bulb flashed by 21V (to the bulb?). What is your advice?

With the 64458....it is really best to shoot for range of 19 to 20.5V delivered to the bulb. In my destructive tests, I use thick wire directly from power supply, so I only have 20 mΩ (milliohms) of resistance in my setup. So now we need to see how to use those tests in a real world setup of a Maglite and batteries.

AW says his D Driver has about 200mΩ, and even with tailcap spring fix, and internal resistance of batteries, you will have at least another 50 mΩ (250mΩ total). Now we need to see how much will that resistance reduce the delivered battery voltage. We use Ohms Law (V=IR) to see the voltage drop of the 64458 which needs current level of about 10.5Amps (see my chart)

Vdrop = 10.5A x 0.250Ω
vdrop = 2.6V....let's call it 2.5V
​

OK, now we go back to battery choices...the first thing we need to see is how does the voltage hold up with a battery when subjected to a 10.5Amp load, which is a pretty heavy demand for small batteries. Most batteries cannot output more than 5-7 Amps, which is why we need to use the Elite 1500mAh 2/3A or 1700mAh AA brands.

CheapBatteryPacks has this 20Amp load graph for the 2/3A cell here. We can interpolate that it will hold its voltage a little better at 10.5 Amps than their graph, but let's assume that under load, these cells will output an average of about 1.2 Volts through most of their charged storage run time (even though it is a changing voltage vs. time curve similar to their graph).

Let's also be careful and take the initial higher voltage into account to protect the bulb for first few minutes before it drops as shown on the CBP curve, and use a practical voltage with these batteries of 1.2 to 1.35V (with most of the run time being close to 1.2V).

Now we go back to the various battery combinations (packs) and subtract the resistance loss of about 2.5V from Maglite setup using 64458 bulb to see what a given battery pack with these cells will deliver....getting as close as possible to ideal range of 19 to 20.5V from my destructive testing.

16 x 2/3A Elite NiMH = range of 19.2V to 21.6V (using CBP output graph range of 1.2 to 1.35V) & subtracting voltage loss due to resistance we get:

16 cell pack - delivered Voltage of 16.7 to 19.1V
​

17 cells = range of 20.4V to 22.95V & subtracting voltage loss due to resistance we get:

17 cell pack - delivered Voltage of 17.9V to 20.45V
​

18 cells = range of 21.6V to 24.3V & subtracting voltage loss due to resistance we get:

18 cell pack - delivered Voltage of 19.1V to 21.8V​

So in theory, with above assumptions in place....16 or 17 cell pack would be the best to use in this setting...unless you added a little more resistance to your setup.

 

[EvilPaul2112]

Lux,
you ARE the man !!!!!

 

[Stereodude]

AW says his D Driver has about 200mΩ

His listing says it only has 30mΩ of internal resistance. Are you sure the 200mΩ is accurate even after figuring in the socket and switch to body contact? :thinking:

 

[LuxLuthor]

His listing says it only has 30mΩ of internal resistance. Are you sure the 200mΩ is accurate even after figuring in the socket and switch to body contact? :thinking:

That was my question to him...because his 30mΩ of internal resistance was taken only from adding manufacturer specs of parts. There is a whole other additional resistance once you include the various contact parts, switch, KIU holder, various wire lengths/diameter resistances. I am certain that he told me 200mΩ when I asked him the total resistance (edit: found his answer in sales thread....just not sure if he meant including stock mag spring in addition to his driver in arriving at the 200mΩ).

I could always check it with my milliohm testing setup, but have no reason to doubt what he told me.

 

[AW]

That's correct. The 30mΩ quote is the total manufacturer spec. from parts. The actual built switch is measured between 150 - 220mΩ.

AW

That was my question to him...because his 30mΩ of internal resistance was taken only from adding manufacturer specs of parts. There is a whole other additional resistance once you include the various contact parts, switch, KIU holder, various wire lengths/diameter resistances. I am certain that he told me 200mΩ when I asked him the total resistance (edit: found his answer in sales thread....just not sure if he meant including stock mag spring in addition to his driver in arriving at the 200mΩ).

 

[kiely23+]

thanks Lux,
great support

 

[smopoim86]

This directly relates to the hotwire i want to do. I'm planning to use 16aa in a 4d with the soft switch. From looking at the bulb tests, any of the 644xx bulbs should be usable with the 16cell pack. (for if i want it to be practical and not just mind blowing)

 

[Stereodude]

Well as practical as a flashlight with a 10 minute runtime can be.

 

[smopoim86]

could use it with a 64432 IRC - 12V 35W ( http://i61.photobucket.com/albums/h75/pike444/bulbs/64432-IRC-35W.jpg ) and get double the runtime or better. Still pretty freakin bright as well.