Runtime for Surefire 9P/C3 with M60 drop-in?

Hello everybody!

Just curious, does anybody have a run-time estimate for the Malkoff M60 drop-in being used in the Surefire 9P or C3 on primaries?

Searched but couldn't find any info on this... Thanks in advance for your input! :thanks:

You get one and a half hours with two cells and an extra 45min for the third so you should get around 2hr 15 min in a three cell light IIRC

thermal guy said:

You get one and a half hours with two cells and an extra 45min for the third so you should get around 2hr 15 min in a three cell light IIRC

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Probably the most popular drop is the Malkoff M60, and I have never, ever seen a runtime plot. I am sure the runtime is probably very good. The data would be interesting.

Bill

Will 2 x 17500's run as long as 3 primaries?

Bullzeyebill said:

Probably the most popular drop is the Malkoff M60, and I have never, ever seen a runtime plot. I am sure the runtime is probably very good. The data would be interesting.

Bill

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I actually did some runtime testing with the M60 in my SF C2 model.

1 1/2 hours (approximately) of full brightness is spot-on. After half an hour of constant on mode, the light gets very hot to the touch. But still able to hold onto it, barely.

After that you get several hours of dimmer light, which just keeps on diminishing the longer you go. Eventually, you get a beam as bright as a Mag Solitaire on a fresh AAA cell.... The M60 is a battery vampire. It keeps putting out light, no matter how "dead" the cells happen to be.

By the time it got dim enough to that of a cheap pen-light, I stopped the runtime testing. My notes with the actual total hours are packed away. I'll try to get to them tomorrow. But yeah, the M60 will dim; but it won't die!

roymail said:

Will 2 x 17500's run as long as 3 primaries?

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It would be very close to the runtime of 3 primaries at full brightness, but there wouldn't be any useful diminishing output, it would just shut off all the sudden... that's assuming you were using protected cells If not, and you managed to run it down far enough to see dimming, it's too late, the cells are toast In other words, use protected cells with regulated LED lights

Eric

mdocod said:

It would be very close to the runtime of 3 primaries at full brightness, but there wouldn't be any useful diminishing output, it would just shut off all the sudden... that's assuming you were using protected cells If not, and you managed to run it down far enough to see dimming, it's too late, the cells are toast In other words, use protected cells with regulated LED lights

Eric

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Eric, thanks for answering my question. I wasn't certain about the runtime.

Monocrom, do you recall if you tested the voltage of the batteries when you first noticed dimming?

The M60 is suppose to run in regulation from 6v-3.8v and that's a lot of drop for just 30 minutes runtime. The drop here would have been from 9v-3.8v

Hey guys, thanks for the info so far!

I'm diving into the drop-in world and trying to decide the best host (6P, G2, G3, C2, 9P, C3).

Leaning toward the C2 or C3 because they are just tough looking lights but love the "tradition" of owning a 6P...

I know, I know, I should just get both :shakehead

The 6P will probably win out, but I like having the rechargeable option of using 2 x 17500 which gives a significant capacity increase over RCR123's. Of course that's just my preference. 6P's are not expensive and should last and last with just a little care. And, of course, there's lots of drop in options.

The DX 6090 is an inexpensive but very good LED drop in to start out with. I did and I still use it. I would estimate approx 120-140 lumens output.

My overall favorite P60 task light is a G2 w/Malkoff M60L.

roymail said:

Monocrom, do you recall if you tested the voltage of the batteries when you first noticed dimming?

The M60 is suppose to run in regulation from 6v-3.8v and that's a lot of drop for just 30 minutes runtime. The drop here would have been from 9v-3.8v

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Sorry, I don't own a meter; yet.

I was using a pair of new Surefire CR123 cells. The dimming happened slowly, little by little. I ended up with several hours of slowly dimming light, after about the first 1 1/2 hours. Having a bit of trouble finding my notes, and have to get ready for work soon. I'll have the exact numbers for everyone after I get home from work. But let's just say that the runtime results were very impressive.

Monocrom said:

I actually did some runtime testing with the M60 in my SF C2 model.

1 1/2 hours (approximately) of full brightness is spot-on. After half an hour of constant on mode, the light gets very hot to the touch. But still able to hold onto it, barely.

After that you get several hours of dimmer light, which just keeps on diminishing the longer you go. Eventually, you get a beam as bright as a Mag Solitaire on a fresh AAA cell.... The M60 is a battery vampire. It keeps putting out light, no matter how "dead" the cells happen to be.

By the time it got dim enough to that of a cheap pen-light, I stopped the runtime testing. My notes with the actual total hours are packed away. I'll try to get to them tomorrow. But yeah, the M60 will dim; but it won't die!

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Please do post your notes. Can you draw a runtime plot. Does not have to be fancy. It will be interesting to see initial start up, compared to rest of run. Will show heat effects on output and sort of show what kind of circuit Gene is using. I know it is running in sort of a buck fashion, but I think it is not straight buck regulation drive. Did you do any current tests at different points of run? Would show increasing current draw from battery as run progresses, or might show a drop in current for a different kind of circuit than straight buck.

Bill

Bullzeyebill said:

Please do post your notes. Can you draw a runtime plot. Does not have to be fancy. It will be interesting to see initial start up, compared to rest of run. Will show heat effects on output and sort of show what kind of circuit Gene is using. I know it is running in sort of a buck fashion, but I think it is not straight buck regulation drive. Did you do any current tests at different points of run? Would show increasing current draw from battery as run progresses, or might show a drop in current for a different kind of circuit than straight buck.

Bill

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I'm not too good at drawing graphs, and no current tests I'm afraid. But here are my notes. (All testing done between 4pm - Midnight, over the course of two days, using two fresh Surefire CR123 cells. Light was constantly monitored while on).

5:00 - 5:30 ~ Full brightness. Very hot to the touch.
5:45 - 6:15 ~ Same as before.
6:30 - 7:00 ~ Same as before.
8:00 - 8:30 ~ Output a bit less. Light is very cool to the touch.
8:40 - 9:10 ~ Same as before.
9:15 - 9:45 ~ Same as before.
10 - 11 ~ Same as before.

Next day

4:50 - 5:20 ~ No change from yesterday's latest results.
5:30 - 6:30 ~ Same as before.
7:00 - 8:00 ~ Light is even cooler to the touch. Not as bright as before.
8:30 - 9:00 ~ Same as before.
9:20 - 9:51 ~ Same as before.
10 - 10:14 ~ Light still going, but incredibly dim.

*Runtime testing stopped at this point since output is only useful for reading short shopping list written in memo pad, held up to the light.

Total runtime = 7 hrs. & 45 min.

Monocrom, you used a lightmeter? If so, then you could tell drops in output due to a lower number (lux, or fc) on lightmeter?

Bill

Bullzeyebill said:

Monocrom, you used a lightmeter? If so, then you could tell drops in output due to a lower number (lux, or fc) on lightmeter?

Bill

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Nope. I used my eyes. The drops in output were noticeable.