Thanks for the reply. Currently I only have a ZTS battery tester. What is an accurate enough DMM for these purposes? I don’t know how to use a DMM on a clicky. Is there a good guide on the forum? Sorry for all the questions. When you say the low half of the modes, that includes the first 3 then?
Pretty much any cheap DMM should work fine. Put it in DC mA mode, take off the tailcap, and touch the leads to the cell and a non-anodized part of the host. It should tell you the mA rating for estimating runtime.
Be careful not to get the light into turbo mode though, or make sure the DMM is in a 10A or higher measurement mode first, or you could blow a fuse in the DMM. The 10A mode won’t be very precise for measuring small amounts of current though.
I forget exactly how the modes are spread out, but … well, let’s see. The source code says this:
#define NUM_MODES1 7
// PWM levels for the big circuit (FET or Nx7135)
#define MODESNx1 0,0,0,7,56,137,255
// PWM levels for the small circuit (1x7135)
#define MODES1x1 2,20,110,255,255,255,0
So, the first 3 levels should be regulated. Level 4-6 should be partially regulated and partially direct-drive. Level 7 is direct-drive only.
Awesome info. Thanks for taking the time to teach me. I’ll get a DMM off of Amazon and see how it goes. I’m still confused on how I switch between modes, or even turn the flashlight on, when the tailcap is off: Maybe it will become apparent when I try it out. Super cool to see the source code and the direct drive vs 7135. Thanks again!
When the switch / tailcap is in place, the switch simply connect or disconnects the tail of the cell to the body of the light. When you connect the leads and the meter, you do the same thing, now with the current meter in the circuit. Which means that when everything is properly connected and the meter is in the right mode, it will show how much current is flowing through the meter and the LED. Changing modes will happen with brief interruptions in the circuit, so be deliberate and firm when applying the leads. I would get the fiddly one on the un-anodized aluminum body first, while you have a second hand, then apply the one to the cell. Having a small vise or a minion to hold the light in place and still be able to see the light come on would also be handy.
Thanks. I think I’m starting to get it. So basically I need to enable mode memory. Then whatever mode I turn the flashlight off in, once I unscrew the tailcap and complete a circuit using the DMM, it will be on in that mode? Or, do I deliberately interrupt the circuit and make educated guesses about what mode the flashlight is in? Sorry I’m so clueless about this stuff.
If you hold one lead on the light body, you can literally just tap the battery with the other lead and it’ll act like you’re pressing the button on the tailcap. The flashlight doesn’t know the difference. It’s pretty easy to operate the light when using a DMM instead of a tailcap.
Totally makes sense now. You folks are awesome!
Just got the Fluke 117. It’s a little more confusing than I thought. I put it in DC current, I think, the A with dashes and a line over it. I connected the positive to the “input terminal for measuring ac and dc current to 10A” and the negative to the “common terminal”. I’m using a Nitcore 700 mAh 18350 that had 50% power left.
- 3 mah- 9.7 days
- 15 mah- 46 hours
- 139 mah- 5 hours
- 452 mah-1.5 hours
I’ll do some more thorough tests in the next few days.