Jinjeng JKK13 USB flashlight arrived

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stolikat's picture
Last seen: 2 months 3 weeks ago
Joined: 08/21/2011 - 05:02
Posts: 161
Location: Cascadia

This is a great product. I am not so good at the reviews but I will tell you all that this device deserves more attention then it is getting. KD was fast to ship this and it is well built and exactly like described.



Last seen: 9 months 1 week ago
Joined: 09/04/2013 - 20:28
Posts: 103
Location: Singapore

The JKK13 & JKK18 really do deserve more attention. With 3×18650 batteries in parallel and 1x XML2, run-time can really be extended, especially if you mod for high currents. I managed to buy two original JKK13 drivers as replacement for my burnt one and got down to mod the light. The large reflector of JKK13 should give plenty of throw.

The JKK13 driver can be used to power 3 LEDs in parellel through 3 banks of 7135 slots, however, only 1 bank with 6×7135 (380mA) is used since there is only one LED. The mod is therefore to fill up the 2nd bank with 7135s and join to the 1st bank in parallel for their respective outputs to be combined. The two areas circled in red needs to be connected to join the 2nd bank to the 1st bank. I used a total of 12× 380mA and 1× 350mA 7135s to give a theoretical output of 4.91A.

The stock LED star was also changed to a Maxtoch DTP star with XML2 U2 1A LED (stolen from my BLF X6! :p). The original position of the LED star sits too low in the reflector, with about a 2mm gap between the top surface of the star and the base of the reflector! Shocked I added another aluminum star (with resist layer sanded off) below the DTP star to raise it higher into the reflector.

Next is to boost the heat transfer pathway from the pill to the body. Added plenty of thermal paste to the screw threads of the pill and potted the gaps between the pill and the body.

Next is to test the current at the LED by connecting an ammeter between a LED lead and contact pad with thick gauge wires.

Below is what I got:

Low: 0.15A
Mid: 1.13A
High: 3.97A

Doing a spring bypass at the driver bumps the current higher

Low: 0.15A
Mid: 1.24A
High: 4.40A

The output is now way higher than the stock light and the hotspot more intense and slightly tighter. Lits up objects 300m away with no problem. Sorry I don’t have a light meter so can’t measure Lux or throw.

Last seen: 9 months 1 week ago
Joined: 09/04/2013 - 20:28
Posts: 103
Location: Singapore

Beamshot of ceiling. In real life, the rings are not that visible. Caused by excessive sanding of the centering gasket.

ISO 200, F5, -1eV

Compared with BLF X6 NW, both at highest. JKK13 at left, BLF X6 at right

ISO 200, F5, -1eV

Underexposed shot to show the difference more clearly

ISO 200, F5, -2.7eV

AlexGT's picture
Last seen: 2 days 3 hours ago
Joined: 06/07/2012 - 17:39
Posts: 4603
Location: Texas

I just modded my JKK13 to add a 17mm FET +7135 driver I won on a giveaway (Thanks Pilotdog68!) and a XP-L 1A V6 from LEDDNA the light is perfect now! the modes are as follows

2% …….7

It is using a variation of this driver he used

The FET +7135 driver does not fit in the space between the stock driver and the pill, so I had to do some extra steps. here we go

1.- Unscrew the side button switch and unsolder the 2 silicon wires and keep them handy (I reused them on the new driver)
2.- Unscrew the crown and remove the glass using a suction cup because it seems to be stuck to the oring that is stuck to the reflector
3.- Using a hook or tweezers carefully remove the silicon O-ring that wedges the reflector in place making sure it does not fall in or touch the reflector.
4.- Remove the reflector by gently tapping on the back of the light being careful not to touch the surface of the reflector store in a safe place along with the led centering ring.
5.- Unsolder the wires from the star and remove, clean underside of thermal gunk if you plan to reuse it
6.- Unscrew the aluminum pill using needle nose pliers and rotating counter-clock wise, clean and put aside for later use
7.- Gently tap the driver with a rubber mallet or other soft material, the driver is held down by glue it will fall out

Now you should have an empty host, clean all debris and oils from inside the host (But Not the reflector, duh!)

Since I planned to use the FET +7135 driver I had to make room for it to fit so I did the following

1.- Un-soldered all the components from the stock driver making sure you unsolder the spring and put away for later use.
2.- Used a metal punch to make a mark on the exact center of the driver on the spring side (Where the spring of the driver used to be)
3.- Drill a small hole through the stock driver using the smallest drill bit you can find, then proceed to enlarge the hole using bigger drill bits until you can fit a step drill to enlarge the hole until its about the size of the 17mm fet driver, I stopped at around 16 mm and proceeded to make a socket so the driver will not move, I had to finish using a dremel and later a file for finishing touches.
4.- Make sure that the new driver is sitting in the exact center of the old stock driver
5.- Now the driver sits inside the stock driver, I used epoxy putty to secure it in place.

After the epoxy cured I did

1.- Attach the stock spring to the new FET driver and used de-soldering braid from the tip of the spring to the center pad (+) of the driver
2.- Attach 20ga silicon wires for the leds to the FET driver
3.- Attach the stock silicon wires to the OTC pads making sure they do not get soldered or make contact to other parts of the FET driver
4.- I soldered 20ga ground wire from the stock driver to the ground of the FET driver

The driver is ready for installation

Now for the aluminum pill

1.- Clean and degrease the aluminum pill
2.- I used sand paper of 1000 grit and up to 2000 grit to polish the inside of the pill where the MPCB will sit,
3.- Find screws that will fit the original threaded holes the pill has, I found 2 that make a perfect fit from an old VCR I disassembled to salvage small screws.
4.- Put arctic silver 5 around the threads of the pill and at the base where it sits on the host and screw in tightly using needle nose pliers, make sure you torque it tight to ensure great heat transfer to the head of the flashlight

The pill is done, now for the driver

1.- Make sure the driver works before installing (Duh! H) )
2.- Cut to correct length (about 1/2 to 3/4 inch) the led wires and pre-solder them for easy install on the MPCB
3.- Put glue on the back of the driver and carefully install it from the back, make sure the silicon wires for the E-switch go through the side hole and the Led wires go through the proper holes
4.- Wait for the glue to cure

While I waited I did

1.- Solder the wires to the E-Switch and put silicon grease and reinstall the rubber booth.
2.- Lap the XP-L V6 16mm MPCB using 2000 grit sandpaper on a piece of flat glass make sure you do not put smudges on the dome!
3.- Pre solder the pads
4.- Make sure that the holding screws for the led you installed are at a good height for the led to slide in.
5.- Put a decent amount of Artic Silver 5 under the led and insert the MPCB to the pill making sure that the correct polarity matches the driver wires
6.- Carefully center the Led and tighten the screws to hold it in place
7.- Solder the wires to the led.
8.- Install the centering ring and reposition the MPCB if needed
9.- Install the reflector
10.- Install the silicon O-Ring
11.- Install the glass
12.- Install the crown
13.- Install the batteries
Pray that you did everything correctly Shocked
Press the button… 8)

Left is a Sunwayman D40A (XM-L2 U2) on turbo at around 1,000 lumens (Only stock light I own)
Right is the JKK-13 on turbo (XP-L V6 1A), it just blows it away definetly doing more than 1,000 lumens, on ceiling bounce is as bright as my modded TN-31
Pic is underexposed to show difference in brightness

Driver epoxied in place

pilotdog68's picture
Last seen: 7 months 2 weeks ago
Joined: 05/30/2013 - 23:31
Posts: 6422
Location: Held against my will in IOWA, USA

Wow! A lot of work went into this one.

It’s always a good feeling when it turns out crazy bright.

My Favorite Modded Lights: X6R, S8 , X2R , M6, SP03

Major Projects:  Illuminated Tailcap, TripleDown/TripleStack Driver