Bright single 18650 flashlight suggestions

Hmmm…. I would just remove the switch from the tailcap first, and make sure everything is clean and soldered properly, then reassemble making sure everything is tightened properly. I’ve had to do that on a few of my budget lights.

It sounds like you’re on the right track with the switch…

How do you disassemble the switch from the tailcap? I unscrewed the tailcap and everything seems pretty solid and I don't want to inadvertently destroy it tearing it apart.

The metal ring around the inside of the tailcap should have a couple of small holes drilled in it. You can use tweezers or small needle-nose pliers to unthread the ring. It’s all that’s holding the rest of the parts in.

I have one of these…
…in my flashlight toolkit just for this application.

Thanks for the tip, that was simple enough. I have a pair of long nosed computer tweezers that fit perfectly in the little dimples and you just press it against the ring to loosen or tighten it. The solders looked okay and clean, no wear, corrosion or foreign material. Button clicker mechanism looked good, etc. so I reassembled it and I'll check it out tonight. Maybe just taking it apart and reassembling did the trick if not I'll examine it again later if need be.

Looks like its okay now. The metal ring may not have been tightened completely when I first got it and I tightened it more. I ran the light on all settings for 6-7 minutes Hi until it got real hot, then 10 minutes for Mid and Lo and all brightness settings were stable with no annoying brightness shifting. I noticed that the battery is slightly loose in the tube and moving the light suddenly can cause noticeable flickering which I attribute to the lose battery shifting position on the contacts.

I’ll be looking around but thought I’d ask if there is a link to a data sheet somewhere that shows lumens and runtimes for each of the 3 brightness modes?


I suspect the flickering issue you had with this light is due to the switch not being able to handle the high current on the High setting of the XML drop-in. This was actually commented on by one of the buyers in the review section quoted here:- “The Switch on my unit can’t handle the draw of the 3-mode XML dropin sold here. Using this dropin, the light will occasionally flicker or dim due to the weak switch. I’ll be replacing the switch shortly.”

I was also looking for a new P60 host. The $8.12 one has a qualifier “Notice: Not compatible with SKU 7644” at the top right of the product page but I couldn’t find sku 7644 anymore so I am hoping it is Not an XML drop-in.

I also noticed that Manafont has another 504b body here:-

which is just a bit more expensive at $11.70 but it seems to have a better build/switch (at least according to the comments). The design is very different though and it doesn’t have the nice metal bezel.

My vote is for one of the ‘L’ series Solarforce Hosts with the drop-in of your choice. I have several and like all of them.

The light is functioning great (knock wood). The metal ring in the switch wasn’t as tight as it was after I tightened it and it stays on at a constant brightness now and that took care of the random “upshifting” and “downshifting” variation in brightness. After that was solved the light would flicker slightly only when the battery shifted around inside, shaking it around, so I jammed the 1” end of a small plastic tie wrap between the battery and the tube so the battery doesn’t move around now and there’s no flickering, just a strong steady beam on all settings. There may be a better way to make the battery fit more snugly in the tube.

On my walk the light functions normally and as expected. On Hi it starts to get really hot so I don’t leave it there beyond 6-10 minutes. It gets warm on prolonged Med but it is handleable. The light performed great tonight and I’m happy with it. I’m trying to determine the lumens on each setting and run times and at some point I might even upgrade my batteries.

great to hear that it is working fine!

if u find the battery too loose, u can just wrap an insulating tape around it. i normally just use a strip from a postcard or something

So am I. I wasn't sure about paper to hold the battery but looks it's okay so I'll give that a try.

I doubt that the batteries will get so hot as to burn the paper but I qualify that I have only done it for xre lights n not for xml. When I first tried, I did take out the battery to check that it wasn’t too hot. I also use the inner core from a roll of toilet paper which is reasonably thick n not easy to set alight. But if u really want to be safe, u could use insulating or masking tape.

The cardboard magazine insert worked fine to hold the battery solidly in place. Tonight I noticed the dimmed brightness again and maybe it’s from not using a fully charged battery and the dimmed brightness is to let you know the battery is weak? I started out with 3.88 V and when I got home it was 3.78V. The non dimming behavior was observed on a freshly charged battery starting with 4.21V and after the walk it was 3.88V. I will check this again tomorrow with a freshly charged battery and see if any dimming occurs.

It did it again with a freshly charged battery within 5 minutes of operation on Med. I operated the On/Off switch 5 times in quick succession making sure to firmly push it all the way down and this seemed to fix it. I kept it on Med and the beam remained steady. I believe I have a flakey tail switch and I’m going to find a replacement tail switch assuming they aren’t married to the particular tube they came with.

Well since you’re going to replace it, it is possible to take the clicky switch apart and clean the contacts inside. I do this to mine if I’ve isolated for every possible problem. Sometimes you get a dirt buildup in the contacts causing poor conduction.

Other modifications I do is if you have the brass piston as a negative battery contact, I always solder those to the spring that pushes it against the battery. On some of my single AAA lights also the spring inside the switch in line of the switch circuitry. I’ll actually solder these to the contacts directly so there is only one point of contact in the switch, and that is the actual switching contacts.


I purchased a set of these: go in my flashlight toolkit as they are a standard size and fit a lot of hosts (including your 504b). It's a set of 10 switches, and it's very handy having these in your kit if you have a lot of budget lights...

I'm sending you a PM...

For Lumens estimates see the Flashlight Wiki and/or Match's tests. I keep Match's charts handy for frequent reference. For estimates on runtime (on single Li-Ion or 3 NiMh) you can take the mAh of your batteries (best if you find out their "true" tested mAh capacity instead of their rated/stamped capacity) and divide that by the current your are pulling from your drop-in in each mode (although be sure to use a decent meter with good leads; homemade thick gauge leads recommended). For example, a 2400mAh battery used with this drop-in pulling 3.5A on high gives 2400÷3500 = 0.69hrs or 0.69÷60 = 41 minutes.

Good batteries are a MUST HAVE for this drop-in! I have this drop-in in a fake Solarforce L2 and love it! My most used light recently.


The funny thing is I took the light out again and it worked flawlessly and to be sure I used a freshly charged battery. I think the switch problem may be in the little black plastic mechanism itself. Then again clicking the switch on and off rapidly may have cleared the contacts. I still need to see how it behaves some more and if a dimming problem presents itself again I’ll see if the rapid on/off operation straightens it out. But for now it’s running fine.

Thanks for the parts link. I’m not sure that I need these yet because the light ran perfectly last night. With a freshly charged battery it ran over 40 continuous minutes on Med with the occasional Hi and Lo with no fluctuating brightness in any setting. It does get warm on Med running that long but not as hot as it would get on Hi for the same amount of time.

I'm finding that I use this light a lot at night. Very bright and a great thrower. I’m running 3.7 V 3600 mAh UltraFire 18650 Li-ion Blue and I’ve read where they are not really 3600 mAh. They were inexpensive and I’m going to get a couple better $10 - $11 batteries from Battery Junction and see how they run in this light.

Well . how bright does bright need to be … ?

Run time , do you plan to run high for extended periods ?

Host body - If you plan on P60 - its hard to go past the New Solarforce L2 builds , my new L2M just arrived this week [ body ] and the only drop in I had was a older XP-G .

And it puts out plenty of light , not as much as say a XM-L but still quite useful .

Im still very impressed with a XM-L drop in driven @ 1.4A …

Solarforce L2 hosts for a body , there just so fine for the $ , then pick a drop in or two