Quick-Review: Kerberos0023's Triple XP-G R5 P60 drop-in for L2P

Kerberos0023 has produced a series of high quality triple XP-G R5 drop-ins, exclusive for Solarforce L2P. You can get them here: https://www.candlepowerforums.com/threads/277951

Last Week i received one of the first units (by the way: shipping from Japan to Germany took only 4 days), and now i want to share with you my experience. First, see some photos:








So just in one sentence: The overall build-quality is excellent. There's nothing much more to say. It has a very good weight, that shows this thing is able to take a lot of heat just with its thermal mass. But the best thing is its accuracy to size:

We got an inner diameter of the Flashlight that is only less then 0.1 mm larger than the outer diameter of the drop-in! This leads to the best drop-in fit I've ever experienced. Very very nice! Perfect fit for L2P!
If you want to use this drop-in in another flashlight, you may need those dimensions:


Now i want to show you this thing in action:

This is a basement room, which is only enlightened by the drop-in (high mode). I changed the exposure time of the camera to such a level, that the photo just looks like what you see in reality. I think you get app. real 1000 lumens out of this little drop-in in the hightest mode!



This is a beamshot made with the flashlight app. 50cm away from the wall. As you can see, it is not absolutely homogeneous, because of the triple light source. But this is not a huge disadvantage... when used in nature or anywhere else, you won't notice any irregularities of course.

ALL IN ALL: I think this is the best drop-in you can get for your L2P.

Impressive beast! Thanks for the quick review.

jp2515 said:

Impressive beast! Thanks for the quick review.

Click to expand...

YES, this thing is a BEAST! Feel free to ask me questions, if you got some

I really hate to rain on the parade but that solder job is "marginal" at best.

..and that's putting it nicely. (for me anyway. )

I know it's working now and all you modders probably do similar work but this thing is being sold on the Custom B/S/T forum and that is what beckons my response after seeing this. The pictures posted are perfect illustrations of what's called a cold solder joint. Cold solder joint are very prone to failure from shock and/or vibration i.e. ever drop your flashlight?!. They also create higher resistance in the circuit and if the current is high enough, this usually leads to an open circuit. Sometimes sooner, sometimes later. I gave that link so that all you budding modders can read up more on this.


Additional Images

Bruce,

Can you do an outdoor shot? Did you use IMR or protected? Have you tried fitting it in a regular L2 or L2M? Thanks.

Armed_Forces said:

I really hate to rain on the parade but that solder job is "marginal" at best.

..and that's putting it nicely. (for me anyway. )

I know it's working now and all you modders probably do similar work but this thing is being sold on the Custom B/S/T forum and that is what beckons my response after seeing this. The pictures posted are perfect illustrations of what's called a cold solder joint. Cold solder joint are very prone to failure from shock and/or vibration i.e. ever drop your flashlight?!. They also create higher resistance in the circuit and if the current is high enough, this usually leads to an open circuit. Sometimes sooner, sometimes later. I gave that link so that all you budding modders can read up more on this.


Additional Images

Click to expand...

So basically, he didn't heat up the contact point enough before applying the solder?

don.gwapo said:

Bruce,

Can you do an outdoor shot? Did you use IMR or protected? Have you tried fitting it in a regular L2 or L2M? Thanks.

Click to expand...

I just went out and made some beamshots








- I'm using cheap Trustfire 18650 cells from dealextreme. The blue ones with 2500 mAh, protected.

- It does not fit in a L2. Can't test it with a L2M, because i don't own one.

can you take some tail-cap readings for current draw at levels?
I suspect you'll find only 1.8A on High, and this is attributable to the battery.
This drop-in will be a great way to sort your batts by performance, as you'll see what ones get closest to 2.5A. Then...see how long they'll hold that level.

All in all great for the drop-in, my suggestion is the it could actually over-perform these beamshots if it were fed a higher quality battery.

Noctis said:

So basically, he didn't heat up the contact point enough before applying the solder?

Click to expand...

Yes, that and the failure to use adequate flux.

Flux, solder, heat and time are the variables you must have in balance for the joint to be a success. You have to get a feel for it, but that only comes from learning proper technique! Only then can one become proficient, second nature and one with the process. The most common rookie mistake is adding the solder to the tip of the iron and then bringing the "glob" over to whatever you are trying to join. You burn up the flux by doing that. The flux is vital for proper wetting and the heat quickly vaporizes it. That's why the timing is important. You heat the joint and then add the solder. You do need a freshly tinned, clean(!) tip so that you get a quick transfer of heat. This is a vital point often missed and not described well. The wattage of the station/iron along with the shape/mass of the tip is also important and needs to match the job at hand. All of it happens in mere seconds, taking me much longer to type this response than to do.

Linger said:

can you take some tail-cap readings for current draw at levels?
I suspect you'll find only 1.8A on High, and this is attributable to the battery.
This drop-in will be a great way to sort your batts by performance, as you'll see what ones get closest to 2.5A. Then...see how long they'll hold that level.

All in all great for the drop-in, my suggestion is the it could actually over-perform these beamshots if it were fed a higher quality battery.

Click to expand...

Ah that's interesting! May be, yes!

[10 minutes later]

Ok i did current messure
Cell: Cheap Trustfire 2500 protected, fresh from the charger
Current draw: 2,6A (high) - 0,7A (mid)
(Low mode i forgot to messure^^)

- Does anyone know the voltage, that a cheap lithium ion 18650 has, when under a load of 2,6A?
- And does anyone know the typical efficiency of the circuit?

Awesome BruceW., to be getting those readings you may have very little resistance in the light (though, the clicky tailcap likely represents the highest resistance especially as current rises into many amps.

Thanx for running the test, you've got a much better batch of trustfire blue than I had. Any chance for a repeat as the cell gets depleted a bit?

Efficiency - geeze, its around here somewhere, i'll keep checking my bookmarks. It can be very high (in the nineties) when vbatt approaches vf+driver overhead (possibly .6 if you've left the protection diode on, there is minimal voltage drop across the 7135 chip if its removed). Of course efficiency in linear regulator is function of the vbatt you provide it (which is also why 6V is not recommended for longer runs on high, as each 7135 has to burn the excess voltage x the 350ma each chip lets across).

I have a similar setup and I've stacked my 7135s to a total of 12. I can get 4200ma on high with my meter. yay

Hi BruceWillEs,

I tried it.:thumbsup:
When battery was 16340, the unit cannot do a normal mode change and did not get enough brightness.
Please purchase 18650 with a new high electric discharge rate.
Thus the unit gets the best performance.

Thanks!
Kenji

Armed_Forces said:

I really hate to rain on the parade but that solder job is "marginal" at best.

..and that's putting it nicely. (for me anyway. )

I know it's working now and all you modders probably do similar work but this thing is being sold on the Custom B/S/T forum and that is what beckons my response after seeing this. The pictures posted are perfect illustrations of what's called a cold solder joint. Cold solder joint are very prone to failure from shock and/or vibration i.e. ever drop your flashlight?!. They also create higher resistance in the circuit and if the current is high enough, this usually leads to an open circuit. Sometimes sooner, sometimes later. I gave that link so that all you budding modders can read up more on this.


Additional Images

Click to expand...

You may be right, although, it really looks more like he used lead-free solder. Lead-Free solder pretty much always looks like a cold joint, even when it's not. Now, there's a whole other issue regarding the reliability of lead-free solder - but since he's obviously shipping to Europe, he doesn't have a choice but to use it.

Ben

I've thought about getting one of those exact drop-ins but after seeing those solder joints I'm not so sure, and I'm surprised he didn't have anything to say about that soldering when he responded in this thread. Although I am terrible at soldering myself, and also have never had to use lead-free solder, which I have read does usually look terriblly like a cold-solder joint as pictured above. It seems his customers haven't had any trouble with broken solder joints yet so that's great though. Thanks for the quick-review and great pics, OP.

I build my own so I don't have an opinion except that I will never use lead-free solder, period. The tree huggers can go to hell on this one. Another thing to hoard now... lead solder.

Rich