With your XPL HI emitters you should see 5-6A in the flashlight with a fully charged 30Q, depending on the specific resistances in the flashlight, like whether the springs are bypassed with larger wires or not.
Of course, how you measure the current will affect the current that flows. A spring bypassed tailcap and switch might have 0.015 ohms resistance. If you measure with a decent ammeter (mine has about 0.03 ohms resistance) the measured current will be slightly less than what will actually flow with the tailcap in place. If you use a length of wire and a clamp meter, the resistance will be less than the tailcap and you will measure more current than will actually flow with the tailcap in place.
One way to more accurately measure the current is to fully charge your cell, run the flashlight for 1 minute, then charge the cell again to see how much charge is put back in. This method requires a charger that consistently charges cells and will measure the charge put back in. The charge put back in, in mAh, multiplied by 60, will give you the average current, in mA.
Interesting, thanks, we will see when my UT210E gets here.
A short loop of stout wire to clamp onto out of the lights tail should work accurately…?
Yes, got at least a half dozen mm that all seem to work well, until now, lol.
Going to try that resistance measurement with current flowing. Can I use that measurement in a formula for a correction factor when using mm…?
Interesting, will have to try that out later. Should the battery rest after charging and after use for a couple minutes? Assuming the light doesn’t have a step down to fudge with readings as well.
Haven’t done any spring bypass, yet. After seeing the driver leads are just 18-24 gauge wire, was a little hesitant to believe the much heavier gauge springs couldn’t allow flow full amp draw. But after seeing how the meter test leads make a huge difference, will try it, and try to get measurement to difference.
My Klarus 2600 is almost charged, going to do the 60 second test on a c8 DD Xp-L hi v2 3b.
Hmmm just tried it, pretty accurate versus the amp clamp I have at work. I’m surprised because of the battery charger variables, consistency of the battery its self etc. Used a lil-500 charger and two batteries (30Q and hg2).
Yes, you wouldn’t necessarily expect it to work well, but the qualities of Li ion cells are such that it does. The Coulombic efficiency is very high for these cells and the termination method chargers use results in a consistent state of charge.
This method used with other cell types, NiMH for example, would not work very well to measure current. The Coulombic efficiency is not good; near the end of charge a lot of the charge going into the cell is used to split water and not towards charging. The H2 and O2 reacting to form water again is the reason NiMH cells heat up a lot at the end of charge. In fact, this is how chargers know when to stop charging; the increased cell temperature results in decreased IR which causes the voltage to drop. This “delta-V” is then detected by the charger.
Did 2, 60 second tests and recharges on both lights, twice to make sure.
Klarus xt11s with Klarus 2600 battery, figured out to exactly 3 amps on both tests.
Nice, and probably very accurate, what its suppose to be. For some reason a tailcap meter amp test doesn't work on this light. Might have something to do with the other switch up front.
Also tested a c8 with a xpl hi on a noctigon, DD and the same Klarus 2600 battery. Got 2.38 and 2.40 amps. Almost exactly what my meter reads...
Looks like its time for a spring bypass..?
Just wondering why the Klarus draws 3 amps and the DD c8 only draws 2 amps, both with xpl hi emitters. Considering the c8 is DD and the stock Klarus xt11s probably has a 3 amp driver. Can that all be attributed to the springs in the DD C8 xpl hi..?
2.4A is pretty low. What I would do is measure the voltage across the LED while the light is on, to confirm that the LED forward voltage is not very high. Measure at the MCPCB solder joints. Then compare this value with the XPL HI measured in this link.
At 2.4A, the voltage should be around 3.3V. If it is, the emitter is probably fine and you know there is a lot of resistance somewhere in the circuit, most likely in the springs.
Did the spring bypass on the top spring, and re-soldered the star and spring board with #18 wire. Concentrated on big beefy penetrated solder joints. After stripping back the original wires thick insulation, wire measured out to about 40awg, didn’t like it. 18awg seems beefy but a little harder to work with.
Didn’t do the tail switch spring bypass yet, wanted to see what the front re-do accomplished.
Well, on my mm with 6” #10awg test leads, got 4.52 amps now.
Did a 60 second mAh test and got 2.40amps, just like before. Tried the 60 sec test again with a new battery, same thing, 2.4 amps.
Redid the tail mm test, still at 4.5 amps, hmmm.
The 60 second test you showed me is also good for troubleshooting since it shows the actual assembled amperage not bypassing the switch/tailcap…
So that leads me to believe the tail switch is the weak link, about to bypass that plunger switch/springy thing. Whats the best way to bypass that thing…?
Yup, looks like a 1/2” long brass cap over the spring, maybe plated steel cap…? Then the switch has a thin steel strip the spring rests on. A plastic cap holds it all together with a screw in tail cap ‘nut’, no board.
I heat the brass cap with a small butane torch and solder a wire and the tip of the spring right into the cavity, then the other end of the wire fed through the spring and soldered directly to the switch tab. You have to be really careful soldering to the switch though, they melt really fast.
Thanks, thats exactly what I’ll try. I’m really good at melting things…
How can that tail cap switch cause such a large amp loss…? It looks like all good solid connections. I even looped the end of the spring thru the switch tab with no change in amp draw…
Wondering what tactile pressure switches do to current draw…?