Need advice for R123 in m3T

code09

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I was reading the posts yesterday, and i discovered that you could used two R123 that top off at 4.2 volts, to power a 3 cell, p90/91 LA. I went home to try it out, i popped my e2c on my e2e, and it worked perfectly just as stated.
So, to go further, i got my cell spacer, and poped my R123's into the M3T. And, once again, it worked perfectly.

My question is, i am planning on getting a A19, and N62 LA for 500 lumens...if i were to put 3 R123's and a cell spacer into it....would it blow the lamp?
 

kongfuchicken

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I don't know if this setup will work but it's generally not a terrific idea to use more than 2 li-ion cells in series for high current bulbs... If these guys get angry, then blowing the bulb will be the least of your worries.
 

code09

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[ QUOTE ]
kongfuchicken said:
I don't know if this setup will work but it's generally not a terrific idea to use more than 2 li-ion cells in series for high current bulbs... If these guys get angry, then blowing the bulb will be the least of your worries.

[/ QUOTE ]

tell me more!! Why would it be a bad idea to use more than 2? what else could happen?
 

kongfuchicken

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A little search will give you all the info you need.
Li-ion cells are prone to catastrophic failure (fire, explosion...) when pushed beyond their limitations.
 

wquiles

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From what I read here the current draw with the HOLA might be just too much for the cells, which might overheat and/or explode, specially if these are unprotected cells.

Will
 

jdriller

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I put 3 r123's in an M3 and used the M4 bulb. Instaflash
4.2 x 3 = 12.6v. SF pushes the lamp to the edge. It is easy to go over it. YMMV
 

code09

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[ QUOTE ]
jdriller said:
I put 3 r123's in an M3 and used the M4 bulb. Instaflash
4.2 x 3 = 12.6v. SF pushes the lamp to the edge. It is easy to go over it. YMMV

[/ QUOTE ]

THanks jdriller, that was what i was looking for. Now i wont even bother to try it...:D
 

code09

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hmmm, i put more thought into it, and i think Surefire batteries come out to be more than 3 volts right? Usually they're like 3.15 - 3.2
So, if there were 4 SF batteries in there, the volts would be 12.6...which would be around the same as 3 R123's...would that still cause a instaflash?
Anyone else other than jdriller give this a shot? /ubbthreads/images/graemlins/grin.gif
 

kongfuchicken

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Regular lithium batteries will experience significant voltage sag under heavy load; much more than lithium ion cells. In fact, SF HOLA are designed to work with that as they are in fact made to run at lower than 9 volts, arround 7.5 IIRC which is why the 2xR123s works with 9V HOLA like the P90 or the N2.
The N62 is pretty much the big daddy of them all when it comes to heavy load; it's the only lamp I know of that was designed to only run intermittently...
 

code09

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kongfu, how about if i were to use three R123's with a M4 bulb...such as the MN61? Would it be safe? would there be instaflash?

TIA
 

larryk

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The reason I ask is that I put two rechargeable 123's in my Surefire M2 using a p90 lamp, and it was noticeably brighter than using the P90 with three fresh regular 123's. Larry.
 

jdriller

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Moe,

I have done what you are asking kongfu. I truly enjoyed my $29 flashbulb. Please tell us how you make out with this set up.
 

kubolaw

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moephiues -

You actually may be able to run the MN61 with just two R123s that are fresh off the charger. As others have noted, 123a's exhibit significant voltage sag under the high current loads required by these lamps. At over 2A current draw, the MN61 can drop the voltage from four 123a's down to 8.2V. So two "hot" R123's may be just right.

John
 

code09

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[ QUOTE ]
kubolaw said:
moephiues -

You actually may be able to run the MN61 with just two R123s that are fresh off the charger. As others have noted, 123a's exhibit significant voltage sag under the high current loads required by these lamps. At over 2A current draw, the MN61 can drop the voltage from four 123a's down to 8.2V. So two "hot" R123's may be just right.

John

[/ QUOTE ]
I will try this out...but will it achieve maximum brightness? What will the runtime be like? I assume the runtime will only last as long as the R123's are "hot" right?

I will try this out later tonight and we'll see what happens!
 
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