I'm not sure it is mentioned anywhere: if you have your leds on copper boards, thermal management has become effectively a non-issue, everything can become much hotter with the led still running fine. This is especially beneficial for p60 lights: the drop-in gets very hot but that does not matter much, and the temperature difference with the shell becomes very large enabling the heat to escape fast enough, even via the tiny edges of thermal contact that the p60 host has.
P60’s are perfect for weapon mounting, I have one on my AR and love it. It’s a great option for a compact light that doesn’t cost an arm and a leg. A Solarforce host, Malkoff m61, and McClicky switch makes for a rock solid and reliable weapon light that costs a fraction of something like a Scout light.
^ This is why I have 3 of them. 
Well I have stock tail cap… but yeah, great platform and lego possibilities are endless… Almost…
I make my own and in this case it’s just a qlite driver from MtnE and a high cri warm xml2 (7D3). Contrast isn’t as sharp as with a cooler tint but I find it very easy on the eyes.
I’ve heard a lot about heat problems, but I haven’t experienced it yet. If I could program the modes it would be High, Medium and strobe. I wouldn’t run it on high all the time mostly medium and back to high for short bursts when I need it.
I have the XM-L2 in 5 mode with the same voltage range. I like the versatility of being able to use different battery sizes or flashlight configurations. Make it a regular size and put it in my backpack or make it a mini and put it in my jacket pocket. I’m going to run the same experiment with rechargeable 16340’s vs the 18650. I like the idea of more volts in the tube even if it means shorter run times. (I still don’t understand why more volts make it run brighter when the amount of input amps should be the same no matter which battery type is used.)
AS for heat. I don’t know why someone doesn’t make an adapter that sits around the reflector with fins that will move the heat from the reflector to the outer shell
It’s a tool that exceeds my needs. It may not be perfect or the best at any one catagory but it works for me and when I need light that is what counts.
I’m no electronics expert, but I think there are two main angles on this.
For a given amp draw at the LED, the battery needs to supply a higher current due to loses from the driver/wiring. Good li-ion can supply high current, but when batteries supply high current their voltage drops. So while they may have a resting voltage of ‘x’, when under load their voltage becomes ‘x - y’.
For example, most protected li-ion cells will trip the protection circuit at 2.75v. But I’ve had batteries that have a resting voltage of 3.5v trip this circuit, what happens is, when under load it dips below 2.75v so trips the protection.
To maintain output from the LED, you need voltage as well as current. An example here would be, an MT-G2 will supply lots of lumens at 3amps. A good single 18650 can easily supply 3amps. But the vf of the MT-G2 is a higher voltage than that of a single li-ion. So despite being able to supply the amps, there is insufficient voltage to power the LED.
Using multiple Li-ion in series means you have a higher input voltage than just using one battery. So for LED’s like XP-G and XM-L’s, your input voltage is always sufficient (ie higher) than needed. This means under load, even when the batteries voltage sag, you’ll still be ok on the volts front. Multiple cells is also kinder in terms of amp draw. If your driver is pulling 3amps, then with two batteries it only needs to pull 1.5amp from each.
Overall this may not affect total PEAK output of a torch, but it can affect regulation, depending on the driver type and circuit used.
And driver type is the other key point here. There are different types of driver, I’m not clever enough to explain them properly. But as I understand it, in simply terms. A driver can use more mAh to boost the voltage it provides to the LED. e.g. many AA lights. If you simply connected the LED directly to a 1.2v NiMH eneloop, it wouldn’t be all that bright. But a boost driver can sacrifice some mAh/capacity too boost the voltage it supplies to the LED. Thus more lumens.
However this can be taxing on a battery and will lower overall run time.
Then you have buck drivers where you have more voltage than you need, here the driver must reduce the voltage supplied to the LED. Sometimes less efficient, but offers greater stable output and is kinder to batteries. Excessively high voltage can mean large efficiency loses and heat.
Most drivers can do one or the other of these, hence why most are voltage limited. But some can do both, which are the ones with the widest voltage ranges. The trouble is, to make them do both, they often end up being less efficient at both ends of the scale.
A nice example of this is too take a look at the MagLed D cell lights (the 2nd gen ones). The 2D and 3D both produce almost identical lumen output.
2D = 134 lumens
3D = 131 lumens.
People often wonder why the 3D has a lower output. And this is down to the driver and I suspect how they are configured. Mag tried to get them similar, but it’s probably difficult to get them performing the same.
The 2D uses 2x1.5v, so 3 volt battery power. This is lower than the LED vf, so this is a boost driver. It uses mAh to raise the voltage supplied to the LED.
The 3D is 3x1.5v, so 4.5 volt battery power. This is higher than the LED vf, although not by much. This is probably a buck or maybe linear type of driver.
Why does this matter?
Well, considering they have similar output and the 3D only uses one more battery. You’d think they would have similar runtimes too. Maybe the 3D should last half as long again than what the 2D does.
But nope.
2D = 8 hour
3D = 79 hour!!!
That’s a huge difference. And what it shows is, the 2D actually has to work the cells fairly hard compared to the 3D, just to match the output.
How does this relate to your question?
Well in Mag’s case they chose to make the 3D offer the same amount of light as the 2D. But higher input voltage could have meant they could have driven the 3D batteries as hard as the 2D ones. If they’d done this the batteries would be no worse off, but you’d have got more lumen output from them and still matched the 8 hour runtime.
There are many options here. Tine foil packed around them. Copper tape. Cut up Coke can’s or remove the large spring and use a bit of copper pipe cut to the right length.
I was more meaning, what versatility are you after specifically, what do you want it to do. If we new, we might be able to suggest something that would fulfil them.
This thread made me go back to the Solarforce website to look around- I hadn’t visited it in months. I found some items I’ll order when funds allow. I started with some Ultrafire 501B (I think they were), then got some of the Solarforce hosts and drop-ins, before adding a variety of lights from other sources.
With an xp-g2 r5 and the KD v2 1540ma driver, they make a great light.
http://www.dx.com/p/uitrafire-504b-aluminum-alloy-replacement-case-for-flashlight-silver-228602#
http://www.dx.com/p/uitrafire-504b-aluminum-alloy-replacement-case-for-flashlight-black-228609#
I've been getting 3 at a time for $7.37 ea.
Fasttech for the drop-in and LED on aluminium star as I don't push them because I like the longer battery life.
I love the low low on the KD V2, the only problem with them is it's a fiddly job attaching the LED leads.
I’m not a collector or really a modder. I like my tools to be functional and fit my needs. I think the first criteria is the flashlight has to have a certain level of bright or what you might call lux. If it isn’t bright (and I’m purposely not quantifying this level) why have it. Second, you have to have the light with you when you need it otherwise what good is it? So it has to be relatively small and light. Third, it has to have versatility to be able to function in unexpected conditions. Generally when I need light it is by definition it is unexpected and somewhat unpredictable.
Level of bright, I can’t quantify this level but for me most of these new LED lights using XP-G/2, XM-L/2, XP-L are all acceptable. Even in the little Solarforce Z-1 with a single CR123 there is plenty of light. The Solarforce L2 series with their drop ins all produce an acceptable amount of light. Solarforce offers three levels of drop ins for their L2 series. I guess they are refered to as P30, P60 and P90 (I could have this reference wrong. I am referring to a L2M mini as the P30, a regular size L2 that will hold 2 CR123’s/RCR123’s or 1 or 2 18650, and the P90 is the L2 series with a full size extension tube and holds 3 or 4 CR123’s/RCR123’s or 2 or 3 18650.). I am satisfied with their P60 XM-L2 drop in with a 2.7v - 9.0v. This is a good amount of light for 2 CR123’s/RCR123’s or 1 or 2 18650’s. For their P30 L2M mini they currently only offer a XP-G .8v - 4.2v drop in. I would prefer the newer XP-G2 to running off a 16340 or 18350. Since they don’t offer the XP-G2 I may have to build it myself using their drop in and replaceing the LED. There top end P90 offers a drop in XP-G 4.0v - 18.0v. To me it doesn’t make sense to have a drop in voltage input range of 4.0v - 18.0v and only offer a XP-G. I want at least a XM-L2 or a XP-L with the voltage input range 4.0v - 18.0v. Again I may have to buy the solarforce drop in and then replace the XP-G with a XP-L LED.
Have to have the light with you. The light has to be handy enough to be in my pocket or backpack when I leave the house. For me the Solarforce L2 series is the right size and weight to easily be with me at all times, except in a business suit where the Z-1 is a perfect substitute. I have looked at others like the Convoy C8 and although the C8 may produce a better lux and beam because of it’s reflector size and shape but it probably wouldn’t be with me when I need it. Having had to walk down a sky scrapers emergency stairwell in the dark and other places without lights having a light with me is critical. I used to carry the Maglite mini with a Xenon bulb which never produced enough light but was the best compromise for the time. But now with the LED’s this is a whole new ballgame.
Last, versatility. I like the idea that I can configure a 1 CR123 mini, a regular tube P60 or add an extension for 3 or 4 CR123’s or 2 18650’s. But what is critical is that I can use CR123’s, RCR123 or 16340’s, 18350’s or 18650’s. Also that I can use rechargeables when they are charged and available but when the power is out for a week because of a snow storm and I can’t recharge batteries I can buy CR123’s and keep the lights going. the versitility of flashlight shape using extensions, the versatility of using different different batteries in the same host and the wide range of voltage input of the drop ins gives me confidence that when the time comes this tool will be able to handle whatever I need.
So all in all I am happy, this is the light for me. If I could make a change it would be to upgrade the LED on the low end .8v - 4.2v drop in and the 4.0v - 18.0v drop in.
Prior to LED lights all that was required was to get the right battery for the flashlight. The incan worked. But with the LED’s batteries and voltage must match the drop in. For many of the LED flashlights I have looked at they have a very narrow voltage input range so they only function with one battery configuration. A lot like the old incan lights. The Solarforce L2 series is one of the few that gives us versatility in configuration of host and batteries. To me that along with a fairly low price is a perfect storm of goodness. Again my only complaint is I want the latest LED’s in the drop ins to squeeze the most lux and brightness out of this tool. I have asked Solarforce to consider making these upgrades when they are ready to replace their drop in inventory, but in the meantime I may have to try modding the drop in with the latest LEDs.
I am enjoying learning about LEDs and drivers and voltage. Since not being an electrical engineer it is difficult for me to understand the difference between volts, amps, ohms, etc But I am getting there.
Yes I can’t tell if ultrafire is copying Solarforce or if Solarforce is copying ultrafire but they are almost identical.
This is the stuff I am trying to learn. Thank you for taking the time to write that all out. But even after avoiding the formulas and equations I still find it difficult. As example, I have the solarforce Z-1 that can only take a CR123 and has a XP-G2. I compared that to a L2M mini with an identical CR123 and has a XM-L 2.7v - 9.0v drop in. Now I would assume that since they are both using identical new CR123’s and that the XM-L has a high lumen capacity of 880 lumens compared to the XP-G2 lumen capacity of 320 that the L2M Mini would be brighter than the tiny Z-1 with the XP-G2. Yet the Z-1 just blew the mini away.No contest. But when I put a 18350 4.2v in the mini then it equalled the Z-1 but it was hard to see any difference. So why didn’t the mini blow the Z-1 away?? I have been told more volts means more brightness but as long as the battery voltage is above the minimum shouldn’t the brightness be determined by the driver? If the high mode pulls 2.8amps (just using as example I don’t have a multimeter to measure the level) why does it matter if it is coming from a CR123 3.0v battery or a 18350 3.7v (actually 4.2v) battery?
You’re among friends. Many of us share that addiction here. Welcome!
That’s because it is not !!!
There are many more choices now than when I found my way here, and that was after a lot more people cut first tracks on the same trails. You can even still get incandescent P60 drop-ins!
But the $7.00 Ultrafire 501b you can buy on eBay today is just as awesomely bright as the $10.00 ones I bought 3-4 years ago, and will serve you a lot better than any Maglight for “Area of Operations” work.
IMNERHO, the only drawbacks to P60s are the lack of “Common, Off-The-Shelf” batteries for them; and the fact no one makes a decent angle-head host for them.
Hardly “obsolete”…
False. LED brightness varies directly with CURRENT, as long as the Forward Voltage is sufficient.
It is. Depending on the rest of the circuit, including the battery.
Because batteries provide some of the resistance in the circuit, all else being equal. For example, even though the driver and the LED can “pull” 2.8A, a Primary Lithium battery (that CR123A) can’t “push” that much current, even in a dead short. The 16350 uses Lithium Ion chemistry which will flow a much higher current.
You’re making good progress on the right track. Keep it up!
Dim
You can take a gallon of water & spread it over the floor and the puddle will be calm and peaceful, hardly noticeable. Push that same gallon of water through a tiny tube, OTOH, and you can carve that floor up into interesting chunks.
All else being equal (an assumption I’m not really excited to make), including drivers and reflectors, the larger light-emitting die of the XM-L will spread its light out over a broad, peaceful area, whereas the wee XP-G2 die gets closer to the optimal point-source of light for which our Parabolic reflectors were designed, meaning its light is more focused & seems (in the hot spot) somewhat brighter.
I’d also assume your two torches have different drivers, meaning different current levels, so this is still largely academic. See if you can at least switch the reflectors back & forth; and set as your goal the ability to unsolder either the LEDs or the drivers so you can switch them as well.
Science + Engineering! Whatta Combo!
Dim
Solarforce have just changed one of those drawbacks maybe? http://solarforce.hk/index.php?controller=products&action=view&id=126
The way I see it, these are the pros and cons of P60:
Pros:
1. Interchangeability. This, of course, is the big one. You aren’t stuck with a specific emitter and/or reflector in a light. Sick of that violet-blue cold XM-L2? Throw in something with a warmer tint. Want more throw than that XM-L2 with an orange peel reflector? Get an XP-G2 with a smooth reflector.
2. ‘Future Proofing’. This follows from the first advantage. Think of how many lights you no longer use because they are obsolete. You can bring an old, favorite light back to life with a new drop-in.
3. Availability of exotic emitters and emitter configurations. Want to run a high CRI XM-L2? Except for a few Armyteks, I know of no light that uses this emitter. Also, if you want to run multiple Nichia 219s, few lights run this configuration. And those that do certainly don’t come cheap. On the other hand, P60 drop-ins using these (and other) less popular emitters are relatively cheap and available.
4. Ease of use. Anyone can swap a P60. And even if you want to build something custom, it’s generally easier to build your own P60 than it is to mod a light.
Cons:
1. Poor thermal management. This is the BIG one. The P60 was originally designed around incandescent bulbs. So to say that heatsinking wasn’t a concern is certainly an understatement. Sure, you can improve things with aluminum foil, copper tape, and strips of aluminum from beer cans. But it will NEVER be as good as a conventional light.
2. Host/drop-in incompatibility. Although P60 is often considered a ‘standard’, the fact remains that it is far from universal. Some hosts simply won’t accept some drop-ins.
3. Increased size. The size of the drop-in basically dictates the minimum size of the light. It would be impossible to make a light of the size of, say, the SC62w that uses a P60 drop-in.
4. Limited host availability. For all the P60 drop-ins available, good hosts are a good deal harder to find. Furthermore, many battery configurations simply aren’t available (or, at the very least, are hard to find). Looking for a P60 host that uses 4xAA? I don’t know of any. Even 26650 hosts are quite rare.
That’s all that I can think of for now. So are P60 lights obsolete? Depends on what you want. If you want maximum lumens, then you should look elsewhere. But if you want a versatile light that can easily run many different emitters and emitter combinations, the P60 lights are unbeatable. Yes, output is limited. But you can probably still run something in the neighborhood of 2A to an XM-L2. And this is good for 600-700 lumens, which ample for the vast majority of situations in which people use a flashlight.
Oooooo!
She’s not the prettiest dame at the ball, but not completely unfortunate to look at, and adaptable enough to be worth taking home.
Thanks!