surefire 6p

[InvisibleFrodo]

I have some very high end battery chargers, and one thing I was considering is setting the charger to peak each cell at 4.1v instead of 4.2v Its really not a huge difference, but I figure it will still help take the edge off of freshly charged cells. Plus as an added bonus that should help extend cell cycle life...


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[lightsdog]

This information is helpful in determining how to upgrade my 6P.

Thanks.

 

[InvisibleFrodo]

I've been finding a lot of sources that say Xenon bulbs are able to be dimmed with no ill effects. In fact, all of those sources say it extends the life of the bulb... So I'm thinking the single rechargeable cell probably can't shorten the service life the bulb.

 

[cland72]

I've been finding a lot of sources that say Xenon bulbs are able to be dimmed with no ill effects. In fact, all of those sources say it extends the life of the bulb... So I'm thinking the single rechargeable cell probably can't shorten the service life the bulb.

Here is a post that kind of goes along with your topic. I'm not educated enough to know the difference between xenon and halogen bulbs, but this might be pertinent information.

Here's a general rule of thumb: for the highest output for a given power for a halogen incandescent the rated life of the lamp is on the order of 10-30 hours, and just off that peak the lifetime jumps to 50+ hours. Sacrifice just a little more lumens/watt and you can get hundreds and even thousands of hours.

While the first part *might* be true, the second definitely is not.

Bulbs die because the filament evaporates. Bulb lifetime is *not* how long until it burns out, it's 'how long it takes XX% of the mass of the filament to evaporate'. You can sometimes see this inside old clear bulbs as dark or shiny deposits, more often near the base (and therefore the source, the hot filament). This is, in fact, one of the reasons normal bulbs are frosted. So the standard doesn't involve dead bulbs, but live ones run for a while until the average filament looses the 'fatal' mass. In general, the hotter the filament, the faster the evaporation, the shorter the life.

Now comes halogens to change the rules. This is a special gas, not a vacuum. This means more heat loss, so right off we need more power, lumens/watt goes down. But if we go higher still, as the temperature goes up (and with it light output) the temperature of the gas goes up with it. Evaporation is going up as well, of course. However the *hot* gas has the ability to cause a chemical reaction that can reattach the Tungsten gas atom *back on the hot filament*, rather than letting it condense out on the colder surfaces. Neat part is where the filament is hottest (it's weakest point) this action is highest, to a first order it becomes self healing.

Under drive a halogen and you revert to 'normal' lifetimes for incandescent bulbs (even lower, actually), and the efficiency (in lumens/watt) goes way down, much lower than 'standard' bulbs at the same levels. At these levels, these bulbs are clear losers.

The 'magic' chemical reaction no longer happens.

Likewise, running batteries flat on such bulbs is probably a bad idea WRT bulb life. While I can't cite such data, I bet that you can kill one faster by under driving it the 'right' amount. For sure doing so, takes lots of useful lifetime off the bulb.

Doug Owen

 

[Andy the Aussie]

I still have the 6P and 6Zs I bought new when they were the pight to have, you know, both still work well for most tasks. The more I read the more I lean of the potential... And the $$$s !!

 

[InvisibleFrodo]

So far so good with my plan to under drive the surefire bulb. My research I've done reading on the topic sounds like xenon and halogen are a bit different. I'm still on the same bulb I was on when I originally posted in this thread. My next idea is to try running a K2 energy battery as the voltage is much lower than a typical li-ion.

 

[bykfixer]

Look at this guy reporting back in 2.5 years later. :thumbsup:
Definitely let us know how the K2 fuel goes please.

Long live the 6P.

 

[scout24]

I went the other way, though an underdriven P60 does hold some appeal. I've got two matched pairs of 18350's that power a P91 in my favorite black bored Oveready 6P. It was coated by Oveready, so all the engraving is all stealth. 10 minutes of awesome output and color temp per set of cells. Good handwarmer for dog walking this time of year...

 

[InvisibleFrodo]

Haha!! I did the exact same thing in an OVEREADY bored out C2 CENTURION. A 9P bulb in a 6P sized light driving the bulb with two Li-ions. Technically, you are doing the same thing. That 9P bulb is designed for 3 disposable A123's. They would start out at about 9 volts with the 3 of them. If you charge your 18350s to 4.2 volts each, you will be starting off at 8.4 volts. Lately I've been charging cells up to 4.1 volts each as it sounds like. This practice will have payoffs in cell cycle life from decreasing voltage stress. That would start you off at 8.2 volts on fresh cells. Nice and slightly under driven for a 9 volt bulb.

 

[fivemega]

I've got two matched pairs of 18350's that power a P91

That's very bright 6P but run time is very short.
By adding 35mm to length (9P size) you will get much more run time (800mAh 18350 vs 2000mAh 18500)
If bored out 6P is final decision, P61 with single 3600mAh 18650 will run much longer with less output. I prefer this to 2x18350 P90

 

[vicv]

Haha!! I did the exact same thing in an OVEREADY bored out C2 CENTURION. A 9P bulb in a 6P sized light driving the bulb with two Li-ions. Technically, you are doing the same thing. That 9P bulb is designed for 3 disposable A123's. They would start out at about 9 volts with the 3 of them. If you charge your 18350s to 4.2 volts each, you will be starting off at 8.4 volts. Lately I've been charging cells up to 4.1 volts each as it sounds like. This practice will have payoffs in cell cycle life from decreasing voltage stress. That would start you off at 8.2 volts on fresh cells. Nice and slightly under driven for a 9 volt bulb.

A p90 or p91 is being driven harder on a pair of li ions than on 3x lithium primaries. May only be 8.2v compared to 9v but those primaries have a big voltage drop under load. A p91 would probably drop them to 2.2v a piece. That's 6.6v. 2 18350 would be around 7.8-8v under load

 

[vicv]

That's very bright 6P but run time is very short.
By adding 35mm to length (9P size) you will get much more run time (800mAh 18350 vs 2000mAh 18500)
If bored out 6P is final decision, P61 with single 3600mAh 18650 will run much longer with less output. I prefer this to 2x18350 P90

I do like the 3 cell size. Too big for a pocket but great for carrying around. Personally though for an 18650 id go with a lumens factory eo4 instead of a p61. Cheaper, easier to find as they're still being made, and brighter/whiter. Especially as the cell discharges

 

[bykfixer]

You can find P60 modules on eBay these days for $8-10. They are typically known as "pulled", which is where someone bought a 6P with the intention of installing an LED. May not be an abundance of them every time you look but they show up often (and sell quickly).

The lumens factory module is a nice alternative. And like Scout said, can be obtained for the 65 mm long rechargeable. (FYI 17 is the 17mm diameter and 650 means 65mm long with a silent 0 on the end)
16650's are getting pretty good too.

If you ever consider going LED with it a Malkoff warm, low-low (M61 WLL) is pretty close to the P60 tint with 10+ hours runtime. Yeah, it's like $40 going in, but if you use the light a lot it'll pay for itself quickly. If you're like me and don't use it often you can tell your friends "3 years later I'm still using the same batteries".

 

[cp2315]

I know this is not a 6p, but here is my incan setup I used recently. A pretty worn solarforce L2m with a surefire P60 drop in powered by a 18350. It is not as bright as P60 should be, at around 15-25 lumens. It works great in the house as my EDC in PJ.

 

[vicv]

That's a neat idea. I had mark @lumens factory make me a couple custom drop in in the d26 size but with the e1r bulb. Thats like 15 lumens but still driven properly for a nice cct. I also use it for navigating the house in the dark. I just pulled the cell to check voltage. Still at 3.85v. Been in there for 6 months and used almost every night with a 30q Samsung cell

 

[Lumen83]

Will the 6p run on 18650s (assuming its bored) with the original incandescent p60 lamp? Anyone have any thoughts or experience on this?

 

[vicv]

Two posts ago it was mentioned as usable and cp2315 liked it......

 

[Lumen83]

Two posts ago it was mentioned as usable and cp2315 liked it......

I believe that was an 18350 though. Not an 18650.

 

[vicv]

They are identical besides length. An 18350 fits in a one cell body. An 18650 fits in a 2 cell body

 

[bykfixer]

Will the 6p run on 18650s (assuming its bored) with the original incandescent p60 lamp? Anyone have any thoughts or experience on this?

Yes it can run on the 18650, but not at full brighness. The 3.7-ish volts of the 18650 will light a P60 same as an 18350 mentioned above.