Hey Republiman, welcome to the forums.
I think you will find that this is a very helpful community and you will ultimately find what you're looking for. The path may be a little less straightforward than you think however. You are going to get suggestions here that are completely different than you might have been expecting. Part of the reason is that there are a LOT of lights out there, many of which you may have never heard if you are new(ish) to the hobby. Also, the technology is changing very quickly. Things you have read online that are only 6 months old might already be irrelevant. My point is that you've come with some very specific criteria, asking about only a couple light manufacturers. While I think it may be possible to get close to your requirements while observing your constraints, please keep an open mind with regard to the suggestions you may get here. There are some very very well informed individuals who hang out on this forum and many have probably been down your same road in search of your same light, only to find themselves in a much different place after spending lots of money in the process.
I apologize if the above sounded like a disclaimer. I just want to give you the best chance for success in your quest for your perfect light!
Now, on to business...
First of all, let's clarify a few things. You mentioned in a couple places that you want your light to run on "regular" and rechargeable batteries. Just to help with some terms you might see here, we tend to refer to batteries that are one time use as "primary" cells or just "primaries". Cells that can be recharged for reuse are often just referred to as "rechargeable". Just for discussion purposes, primaries in this context (CR123 cells) are 3 volt cells, and two in series will provide 6 volts. Alternatively, rechargeable CR123 (also called RCR123 or 16340/18350) cells, fully charged will be about 4.2 volts with 2 in series at about 8.4 volts. A single 18650 cell has the same voltage (4.2 volts) but is twice as long so you can only run one in the size light you're asking about (only 4.2 volts). Notably, there is no "primary" 18650. At least not that is readily available on the market or that is ever really considered among flashlight enthusiasts. We deal strictly in rechargeable 18650 cells.
I say all this because what you're asking for is a light that will operate across a voltage range of approximately 3 volts (a single depleted 18650) to 8.4 volts (two fully charged RCR123s). That's a relatively broad voltage range. The driver that could accommodate that entire voltage range would probably not be very efficient at one end or the other, and is probably less efficient overall than a circuit designed around a narrower voltage range. For that reason, you're much more likely to see lights in this category designed to work between 3 volts (a depleted 18650) to around 6 volts (two fresh primary CR123 cells). In other words, the requirement to run on 2 RCR123 cells is going to limit your options quite a bit. Now let me tell you why that's not such a bad thing.
Even the highest capacity RCR123 cells have relatively small capacities compared to the best 18650s. Actually, much less than half the capacity you might be expecting considering they are effectively half the size of an 18650. Also, because you're running them in series, the voltage doubles (8.4 vs 4.2) but the capacity does not. So if you're running 2 typical 18350s, your capacity is only ~800 mAh. Compare that to the highest capacity 18650s available now at 3500 mAh and you can see the disadvantage to this setup. Now, admittedly, the driver wouldn't have to draw as much current from the two 18350 cells in series (because of the higher voltage) to deliver the same output, but considering the relative inefficiency of the wider voltage range circuit and the much lower capacity cells, you will never come close to the same runtime.
Now a word on primaries. You mentioned something about Olight saying CR123s could be used in "an emergency" and questioned whether they would last as long or perform as well. The fact is, they wont. Again, CR123 primaries are typically rated at 1500 mAh capacity. 2 of them in series do make 6 volts but still only 1500 mAh (and still significantly less than an 18650). Also, for a light that is producing 1000 lumens, even with the most efficient LEDs available, the light will still be drawing 3+ amps from the batteries. Primaries are not really rated to handle a current draw that high. They will likely survive, but they will experience a phenomenon called voltage sag where the cells may test at 3 volts, but under load (when the light is on high) they will produce something less than that. This means that you should not expect to get the maximum advertised life out of your primary cells. That said, primaries can be useful to keep around for emergencies. If you don't have access to a charger but you have a couple spare primaries lying around, they will power your light. It may not be a great idea to run your light on high for extended periods, but on the lower modes the cells will perform quite well. They also have a very long shelf life, are light weight, and if purchase from the appropriate places, can be fairly inexpensive.
So what we've established here is that the best performance you can get from a light in the category you're looking at is going to be using an 18650. Primaries work in a pinch but you shouldn't expect to get the same performance from them that you would an 18650. There are very few lights in this space that are designed to accommodate two RCR123 cells, and you performance in that scenario will also be lacking.
Now that the battery discussion is out of the way, let's talk lights. Fortunately, the single 18650/2 x CR123 form factor is among the most popular in existence. Nearly every flashlight manufacturer has at least one contender in this space. That said, I'm curious how it is you have arrived at Fenix and Olight as your preferences? I have no issues with either and in fact they both have great contenders here, I'm just curious why you have singled out those two companies? Are they more accessible to you? Can you get a deal on them? Have you had personal recommendations?
Full disclosure, I do not own lights in this form factor by either company. I have several Fenix lights of much different design and have owned Olights in the past and I've had only good experiences. I think the lights they offer currently that (almost) fit your criteria are the:
Olight:
M20
M21
M22
M23
Fenix:
TK16
As you mentioned you would like a light that would also serve in a SHTF scenario, you will notice that these lights fit within their respective manufacturers' "Tactical" light categories. This often means that they're designed for harder use (or are at least advertised as such). But, they squarely fit almost all of your criteria with the exception of accepting 2 RCR123 cells (which I have hopefully convinced you is not a huge loss).
I would urge you to check out some similar offerings from other manufacturers as well including
- Surefire
- Armytek
- Eagletac
- Nitecore
- Klarus
- Jetbeam
- Sunwayman
Some of these will actually accept 2 x RCR123 cells as well if that is still among your requirements.
and so on.
Finally, let me offer up one more possibility. There are many very good P60 hosts out there that will accept drop in modules which can be configured with any number of mode combinations, accept a wide range of battery voltages, and can be subsequently swapped out if you decide you need something different later on. Some good sources for these are Surefire, Solarforce, and Malkoff to name a few. The drop in modules can be had from Malkoff, Vinh Nguyen, Nailbender, Solarforce, Oveready, and many others. Just do some googling of those names to see what's out there.
If you have any more questions or would like to discuss some of these options further, just respond in this thread.
As for batteries, there are many options out there that will fit your needs. Rather than discuss them myself, I'm going to point you to a place that has emerged as a great resource for both reading about batteries and purchasing them. Google Mountain Electronics. Click on batteries at the top of the page and select the battery size of your choice. You will have MANY options to choose from. You may first want to decide whether you want protected or unprotected cells. I would recommend protected cells for your use scenario. Once you have that narrowed down, you can browse by capacity, chemistry, and price. Once you click on a battery, there is usually a very good description of the merits of that particular cell. As far as 18650s go, no light in the category you're looking for (short of using one of Vinh Nguyen's crazy monster drop ins) is going to really tax the cell. As such, you should have your pick of the highest capacity cells for the longest runtime possible. Again, if you have further questions, there are plenty of other threads discussing batteries on the forum here or you can come back to this post with more questions.
Cheers!
-G
