Fenix L2D CE on Turbo with Cree Q4 - almost 1000mA

[rantanplan]

[...]
When measuring battery current draw, multimeter internal resistance plays a very big role due to low voltage and high current. If it's not a high end multimeter, you may get a reading of 1.2A while the actual working current is 2A. A good workaround is inserting a 10 milliohm resistor to complete the loop and measure the voltage over the resistor to get a better idea of the actual current.

Yes, that´s true ... you should always think about possible influences of your measuring equipment onto the measured circuit.

On the other hand ... I think most current measurements are taken with bypassed tailcaps, so you would have to consider the difference between the resistance of the multimeter and that of a mounted tailcap. My guess is, that the resistance of the tailcap (with switch) is often greater than the resistance of a multimeter setup.

But it´s a good idea to use a sense resistor when you try to measure the emitter current. Soldering in a resistor ensures that the circuit is closed. Remember, boost circuits don´t like open output circuits and nearly all of them won´t survive one.

My L2D CE modded with a Q4 sucks 1.5-1.6 Amps out of fresh NiMHs. Before mounting, I checked the Vf of the emitter and it was 3.45V @ 350mA.

 

[wintermute]

My L2D CE modded with a Q4 sucks 1.5-1.6 Amps out of fresh NiMHs. Before mounting, I checked the Vf of the emitter and it was 3.45V @ 350mA.

Which NiMH batteries were you using - some exhibit more voltage sag then others under a 1.5A load. The LSD NiMH (Eneloop, Titanium 2100 LSD) have less of a voltage sag then the others. Regardless, sounds like yours is getting almost the same as mine. I am going to build a host with a U-bin SSC and VIP-1000 driver next week to compare the two...then we'll see.