Review: Manker U21 - a small thrower

Thanks Tom!
Real nice light, that reflector looks very good made.
(Does it run Narsil ? :wink: )

I was able to get the driver loose, took pics, hopefully I'll get them up soon. I was able to poke a solder pick tool through the LED wire holes from the top, applying pressure, and broke through the epoxy seal of the driver. It's a two piece driver - one board is the contact board (plus electronics), the other is screwed to the top of the pill, which is the solid shelf the MCPCB sits on. There's a wire harness connecting the two boards, so doesn't seem possible to easily separate the USB charging from the driver electronics.

Good news: the driver can be replaced (stock driver contact board is 21 mm 29.8 mm x 2.05 mm)

Bad news: if you replace the driver, you will lose USB charging, and you would have to glue/epoxy the driver back in place

There's also a 4-5 wire harness coming from the switch, but being there is blue and red LED's on the switch board, that makes sense.

Weird in that the 2nd PCB that holds the USB connector is mounted on the pill top - that has to get pretty hot from the copper MCPCB.

My plan to modding this would be to piggyback in a 17mm FET+1 driver using Narsil, scrap the USB charging, removing the 2nd PCB mounted to the pill top, and going with a dedomed XM-L2 U4 1A, so I can use the existing centering piece. Lumens and throw should be increased, keeping the max draw on the battery about the same or lower.

Do you can say me which diameter the driver has?

It's 21 mm 29.8 mm x 2.05 mm, as mentioned above. Again though, there is another PCB in there.

Thanks for reviewing.

Question: Is there an ugly yellowish inner-circle in the middle of the beam when projected on a light-colored surface?

Wish I had a chance to do beamshots, but I looked at it carefully on a white wall, and I thought the hot spot had a pretty even tint, and nice pure white tone. On Budda's review, those wallshots look green, with a darker tint corona - very different than what mine looked to my eyes.

Right now, I got the light opened up in pieces so can't take wall shots

Thanks Tom! Can you bump the current up, via the resistor (s) ?

Well, actually I tried last night, finding a large R050 on the secondary PCB, and stacking an R120 - light didn't work after that, though the dragon's breath mode still worked. Pretty sure the R050 has something to do with charging, not output. Lots of resistors, but none others that appear to be low value large ones.

Edit:

I backed out the resistor mod, and the main LED no longer works. Not sure if I broke something from the resistor mod, or just from tearing it down - can't find anything obvious wrong. I will probably go ahead and do the full mod upgrade, possibly dedomed XM-L2 U4.

Minor updates in the OP - typo fixes and adding more to reference links. GearBest has a listing page for it now. Could this mean a possible future discount?

Got my U21 today, loaded it up and turned it on and the first thing I noticed, a dot in my hot spot, OFF! Sure enough a spec of crud waiting to smoke up my brand new (milliseconds) old REFLECTOR and Melt down into my emitter! :person_facepalming:

(K70) Disaster avoided, clean and scraped what look like a piece of shiny metal, suspect it came from the threaded reflector, thread shed?

Also noticed that it looks to be a different driver, well the number on the driver is not the same as Tom’s? Mine reads DLO 46

Centering ring, well it’s more of a cup if you will, is sloppy around the emitter,way too sloppy for me. Spot is no where near centered, mcpcb floats and twist’s around, nothing to stop it from rotating on the thermal grease? Found the (-) lead pulled out and all bunched up and the (+) dangerously close, possible shearing action! It will be fixed!

The spot is not well defined until you hit turbo and even then the corona washes it out some from the large (centering cup) that surrounds it? Looks great 1ft from a wall, 10-12ft away not so much! It will be fixed!
This will all be taken care of……I’ll charge her up and see whats up, it will be going against the (Bombeta) Cometa de-domed old XPG2 5.8 amp with the Z1 glass and the stock JAXMAN X1….tonight!

Thanks for the review! Teardown photos/analysis very interesting.

The transition from design to production is a problem in purchasing flashlights from new makers or manufacturers.

Mine does not show the problems you mentioned (I did not examine the driver), but mine might have come from an older production run.

I hope you have contacted Manker.

I got my U21 last week. Same driver as KB. Tail threads well lubed. Other end bone dry zero lube. No crud but same off center led. Centered easily. Good solder connections. Excess thermal paste. No twist noticed when reassemble. Hot spot very well defined at all. Noticed better after TLC. Will also compare with the stock X1. Thanks KB for telling what to look for:THUMBS-UP:

Mine was an engineering prototype, they sent me not realizing til after it went out, so driver probably somewhat different.

I was tempted to get this light awhile back if issues are arising glad I didn’t. I can’t just easily mod and fix a light like most of y’all can. If I spend $70 on a light I expect it to be perfect. Not need led centering. Or wires jammed in about to short like the cometa they made.

The light still picks my interest though being 1 cell xhp 35. I wish they would have a true turbo with no step down. I end up sending my stock lights with it for modding. I can’t stand a turbo step down. I have it on turbo for a reason. If it gets to hot or I’m done I’ll step it down. I could see mayne a temputare step down as a safety measure 80c+ but not timed. Or at least let the user have different mode groups with or without it. Hopefully more manufactures like convoy or thorfire make a light like this. At a cheaper price point their known for

Mine doesn't turn on looks like a switch failure

Hello. I bought it 6 months ago from gearbest and use it only 10-15 minutes. It was perfect. Yesterday get ready for camp but the light didn’t work. I prepared a video for it. *Battery is OK. *Switch and under switch leds are OK. (with usb charging port) *XHP35 hi main led is OK. (with usb charging port) *Tailcap is OK. *4.22 volt is OK with usb charging port. but cannot charge battery. I think it imagines battery is fully charged * I tried to loosen body tube from head but it is imposible. Can you say what is it about. Driver or what? Video- - YouTube

Great review and photos as always Tom e ,I really love the mod you did on mine it is now my ace
.I was because of this initial reviews i bought this light.

Here is mine bought from Geabest faulty switch after 6 months. https://youtu.be/Mrw7tg5LhVw

@ Tom E ,

I got my Manker U21 about a week ago , and after I readed your post , something seemed to be not right..., I measured mine ( Fluke , with short and thick probes , IMR26650/4200mA/40A , from Nitecore ) , and my readings , especially on high and turbo are different.., as follow :

Low : 0.02A

Medium 1 : 0.27A

Medium 2 : 0.65A

High : 1.30A (!)

Turbo: 3.70A(!)

So , I decided to do some math , to see what is going on...

Your driver :

P output : 12V X 1.1A = 13.2 W

P input : 4.2V X 5.44A = 22.8W (!!!)

The efficiency of the driver = around 58% (!!!) .., even the worse boost drivers I worked with , doesn't have such low efficiency !!!...

My driver :

Poutput : 12V X 1.1A = 13.2W

Pinput : 4.2V X 3.7A =15.54W (!!!)

The efficiency =about 85% , this is an acceptable efficiency ( I've seen and tested boost drivers with 95%...!)

I don't think that Manker , as many other manufacturers , will exceed the max current to the led ( in our case , for XPH35 HI , is 1050mA..!. I took in my calculation 1.1A ...) so , or your measurements are wrong , or your sample has one of the worst boost drivers I ever seen...no pun intended !

Anyway , that 5.44A to your tail is far too much , and due to the efficiency of this kind of led you should have more than 1800Lm at the output , including the loses...

Sorry , I did not intend to disturb you , but , as I said before , something is NOT right...

I believe I read the early samples of this light were giving 1.5 amps to the led which would be 18-19 watts and so just a bit less efficiency than your numbers. Although there is some estimating in both cases here.