So i do quite a bit of camping and of course flashlights are out at night. I try to give my 10yr old boy one of mine to play with and he “always” chooses my old 18650 zoomie (cant remember the brand name but its very cheap, like $15 max).
Its starting to spazz out every now and then and i have to clonk it somewhere to make it run again.
Any suggestions for a replacement for around $20?
Convoy bd04?
UltraFire SK-98 XM-L2 U2 (FT's SKU4521200)
UltraFire SK98 LED Flashlight SKU4521200 @ FastTech
This flashlight can be easily upgraded with an H1-A boost driver plus an XHPx0 emitter. In such case, high drain cells and upgrading the low quality stock switch are recommendable.
do they still make any with a round beam pattern when its zoomed in instead of a square?
i would prefer a round beam. thanks for the recomm!
Dunno if I’d go for overkill with that driver, but in general, yeah, any SK98 is going to be a great host, but will suck if used unmodified.
Replace the switch, driver, and emitter, and you’ll be set. I always recommend a nice 1-mode 20mm driver, and fill the almost-certainly-hollow pill with something like metal-filled JB-weld or a stack of filed’n’soldered pennies.
Heat transfer will suck anyway, guaranteed, so a nice 1A driver (eg, 1.05A or 3×7135) will give good brightness and decent runtime. If you insist on multiple modes, well, I’m not sure what 20mm drivers are out there that’d fit. The usual NANJG and such are all 17mm.
“Two is one, and one is none”, so don’t be afraid of carrying multiple lights for multiple functions. At least you’ll have redundancy.
Nope, not really possible, as once it’s in-focus (ie, zoomed), it’s projecting an image of the chip.
I always used to just leave it a tad “unfocussed”, a little blob of light, but not completely focussed.
Anker LC90 has a rather round beam when zoomed in.
Not really tried, but I believe a 0.1mm copper sheet shim (or two) under the emitter would probably sort of fix the fully focused “batsignal” :-D issue.
Heat transfer in that SK98 is decent, it is possible to run the light on high without issues. I believe I did measured at most ≈90°C on high with an infrared gun aiming at the emitter on top of the lens, as it came stock (≈6.5 - 7W at the led) with the stock emitter, mounted over an aluminium non-DTP board.
Related: [[ GXB20 Driver – Homemade Constant Current Programmable XHP50 Single-Cell Boost Driver! ]]
im not into modding at all 
that anker looks nice, thank you.
Here is the LC90, 1 meter from the wall, on low setting.
Now, this light is not without cons… main ones being disco modes which cannot be bypassed/hidden as well as fairly quick step down when in high mode. Also, no moonlight mode, and the low mode isn’t all that low.
There’s also the Brinyte B158 and Brinyte B158B which have been favorably reviewed. Usually $30 or under….I think I’ve seen discount codes from some of the users on here too to bring them down.
Just a little note, contigo. 0.1mm copper sheet is affordable and readily available in eBay & AliExpress. Cutting a ∅≈20ish millimeters disc shim is very easy, and placing it under the emitter another piece of cake. You may want to disassemble the emitter on those cheap flashlights anyway, to put some thermal paste below the MCPCB.
Cheers ^:)
The b158 looks like a great zoomie. Had I known about it before getting the lc90, I would have gotten it instead.
Maybe a bit off-topic but, any decent zoomie with a 20+mm driver trunk? Preferably tall. 
I like PWM free fully regulated flashlights.
Just wanted to throw out a suggestions on the cheap side, the branded "Warsun" zoomie's with the ~65mm aspheric lens have served me well for the price in their stock configuration. Sometimes they are listed under the brand "comunite" or something else. (Edit: It turns out, after double checking my actual light it is branded "Sharp Eagle" so apparently there are a lot of different knock offs of knock offs of this cheep zoomie) I got mine on ebay and have definitely gotten my money's worth (about $15 I think). I wouldn't recommend this light for modding, look at some of the other threads where others have done tear-downs on the light. But for around $15-18 U.S. its plenty bright enough for me to use to drive my small boat at night down a pitch black bayou, which is pretty impressive for a cheepie light. There may be others out there that are better for modding, or maybe I just got lucky with mine, but straight out of the box for $15 this light is really useful and so cheap I'd care more about losing the battery inside of it than the light itself if I dropped it overboard. Maybe you could do better if you spent $25-30, but at $15 unmodded, I get a lot of use out of it. It would be a good camping light too I imagine. The only downside is the blinky strobe modes, which almost all of these price-level lights will have unless you change the driver or mod the existing one. Chances are the XM-L inside is fake too, but its still very bright, well centered in the lens, and has good runtime without overheating with whatever driver it comes with stock. You get what you pay for, but for under $20 shipped its a pretty good deal in my opinion and sturdy enough for outdoor use. It's never the only light I take with me, but it gets the job done well everytime so far after using it for about a year in situations where I'd be in rough shape without a light. Oh, last thing is its listed as a 26650 battery light, but 18650's fit inside easily with a little cheepie plastic spacer, and sometimes I dont even use the spacer. I also like the 26650 size handle just because it can be easier to grip and manipulate while wet and in the dark. Here's an example, but do some searching around and different brands and prices can be had easily:
Edit: the warsun/comunite has a 50mm lens it looks like.
https://budgetlightforum.com/t/-/44751
Ok maybe you can use one of these lights for a mod project, if you have incredible skill and patience like Cula. Jealous.
The best cheap zoomie that works decently that I have found is the OxyLED MD50. If you are in the US, they used to periodically have coupon codes on SlickDeals for them on Amazon. Even without a code, it is reasonably priced if you are buying the flashlight alone. Only $10. With the code, it was $10 including a case, battery and charger (batt and charger are junk anyway).
Of all the cheap zoomies I own, it is the closest that I have found which is actually close to the advertised spec. It used to be advertised as around 800 lumens (the lumens have been removed from the product desc) and IIRC I measured it as being around 600-700? The downsides are purplish tint (I never measured the temp) and unavoidable blinkie modes. Although on the plus side, there is no mode memory, so I guess you can technically avoid strobe if you never cycle through modes fully.
The other nice thing about this light is that you can power it with 3xAAA. If you are giving it to your son and it will presumably be dropped and abused, this is the best route. The power is not as good as with 18650 obviously but still decent. I currently have the light left in 3xAAA configuration with NiMH batteries and gave it to my wife. I don’t have to worry about abuse or battery care. I’m not even sure where she left it.
https://www.amazon.com/OxyLED-Flashlight-Zoomable-Resistant-Emergency/dp/B01LZAIN93/
FYI - Some of the pictures on the Amazon listing are a little misleading/confusing. There is not a “spike” on the bezel, that is the black lanyard in the background.
awesome suggestions thank you so much!
so nice with people in the know 
(even for very cheap lights).
can anyone recommend one with a magnetic tailcap? (18650)
not sure where you live so the price may be different for you. I like my Wowtac A3S a lot. It’s small, light and powerful. Or you could go to Costco and get one of the duracell zoomies that take C or D batteries. They would be even cheaper but much bigger and heavier and I doubt the quality would be as good as the wowtac