FandyFire HD2010, looks like will be 26650 compatible

I have found tailcap current to vary greatly depending on how tight the cell sits in between the springs (at least in the UF HD2010). If I compress the +B spring all the way flat I get a tailcap current of 5.52A. If I just touch the probe to the -B (without compressing the +B spring at all) I get a reading of 4A.

Pics... (again this is for the Ultra HD2010. I am not sure if the Fandy HD2010 behaves the same way).

Battery Space LiNiCoMn 26650:

With a Sanyo 18650...

Thank you Kramer, I forgot about you posting about this. I just assumed it would only happen with the Ultrafire version, but I guess any version may act that way. The other day when I first check the tail readings, the pressure I used holding the probes was very little. Tonight I was more more aggressive when checking it and it came right up to where I felt it should be. A really great and bright light this is.

If any one is looking for good protected 26650 batteries

https://budgetlightforum.com/t/-/8030

I killed 2 HD2010´s with full charged 26650 and pressing the spring.

Highest reading was over 7A, too much for the LED......dark.

Modded with 7135 driver and XM-L on copper the flashlight is one of the best!

Why does pressing the battery against the spring draw more current?

You're increasing contact.

Thats good to know, I was considering some copper-braid low resistance mods for this light and decided not, since i have no way to measure the actual current through the LED.

Hey Andi, where did you get a copper bonded XML, what flux BIN is it? I already have a 3.5A 7135 driver incoming for this light.

I am thinking a U2 copper bonded, 3.5A and a UCL lens and I should be at / near 50K lux.

This light modded has over 50KLux. ;)

My LED was from LED-Tech (Germany): XM-L U2 1C.

Hi folks, would anyone have any idea what the problem may be with my Fandyfire HD-2010. When I use my 4Seven 26650 battery or my KK ICR 26650E, it works perfectly and switches to any of the 3 modes without problem. However, when I toss in one of my new Trustfire 5000 button top batteries it'll only work in high mode. I only have 2 Trustfire's and it does the same thing with either one of them. Any ideas?

What happens when you unscrew the tailcap a little to alleviate force on the cell... same thing?

Is the pill screwed tight into the host body? If you unscrew the bezel (carefully so you don't tear the gasket), and remove the reflector can you mode flip without the reflector? Suspecting there may be a LED+ short to the reflector.

I've tried unscrewing the tailcap in small increments to the point it pops off, including the battery tube. Having to much pressure doesn't seem to be the problem. The pill is screwed down and tight with a bit of AS-5 on the threads. Even with the reflector removed, it will only run on high mode with the Trustfire 5000.

Yeah, my first thought was the reflector shorting, but I did the mod you came up with you did on your Ultrafire version. This is the weirdest thing I've seen in a flashlight. The other brand batteries work great in this flashlight. Something about the Trustfire cell is the cause. I'll keep at it and post if I come up with something. Thanks for the suggestions.

that is completely bizzarre.

can you unscrew the battery tube and wire the battery straight to the DC-DC board +Vin and -Vin?... just clear the table and omit any side affects of the tailcap and body all together. See if you can mode flip it by touching wires to the DC-DC board.

Same thing is happening with my protected UF 2800's from DX. If the flashlight body is too short for the cell, seems the tailcap presses the protection circuit, and it loses contact, i.e. turns off the flashlight. For instance, it turns off in UF V6-T60, but not in FF HD2011 and other longer flashlights. This does not happen on TF 3000's, though, at least wherever I tried it.

Edit: you said pressure/unscrewing makes no difference for you, so not exactly same situation.

Here a pic of a chanched pill:

A little bit of rasp and a 8x7135 driver(with 2 extra 7135) will fit. ;)

deal on Dino:

http://www.dinodirect.com/flashlight-hd-cree-t6-600lm-led.html

My Ultrafire versione does exactly the same too (except I don't have other 26650 than the Trustfire 5000)

It works all the modes with -any- 18650 I can throw at it, it works with recycle bin batteries, it works with AW2900 fresh off the charger at 4,19v

But if I put the 26650 TF5000 it has high only.

Tried unscrewing the tailcap in small increments, nothing happen, still high only.

Made all the check and mods suggested here and on the other UF thread (cleaned, reassembled, insulator disc on the reflector, tightened pill ring and driver ring, and no results. Still on high only.

Then all of a sudden it started working all the modes with the 26650 TF5000 too! WTF! I thought... take out the cell, measure Voltage, and due to all the testing the 26650 has discharged a bit and now reads 4,10v, and all modes works. If I charge the 26650 to more than 4,10v it starts weird again with high mode only. So definitely it's something related to driver and voltage sag under load, because a charged 18650 with 4,19v unloaded works perfect, meanwhile a 26650 partially used at 4,13v still makes high only, drop anothere mere 0,03v and it start working again...

If this driver is Fet based with high pwm, to my understanding in high the Fet receives a pwm with a 100% duty cycle, e.g. constantly on. This is no strange, as for example the electronic speed control for RC models works the same way, hi-frequency (over 1,5Khz usually) Pwm from 0% to 100%. But this does not explain why the system goes funky above a certain voltage.

Any idea or suggestion, other than a driver swap?

Oh, I didn't mention, felt in love with this light! Nice size, throw like crazy with still usable spill. Great!

Great investigative work!! in my HD2010, it works 100% fine regardless of cell voltage or cell type. HOWEVER when I use my Fluke to meter the tailcap current draw it behaves like a one mode only. I never could figure this out, but I think you nailed it. I think the added Voltage (or current whichever it may be) drop through the switch presented my driver with exactly what it wanted to “see”. The fluke (and its lower internal resistance) would cause it to behave like yours.

I’ve since switched it to a 10x7135 driver, and all is well. its a GREAT light, I think worthy of a driver mod/upgrade

Oh yes, this could be very well the reason why nobody was able to measure the modes with the Fluke but only High-SOOS. The resistance of the Fluke and thick cables was less than original tailcap spring and switch! Good call!

This means the driver swap is almost a must now...

Could you please explain in simple terms if possible about your flashlight only working on less than 4.1 volts. Thanks.

Sure, very easy:

with a 26650 TF 5000mAh

cell charged above 4,1v > no modes change, only high (you can try switching it fast or slow or just tap it, no way, it's like having a single mode incan)

cell partially used below-equal to 4,1v > driver works with all 5 modes regularly (hi-mid-lo-strobe-SOO)

with a 18650 (good or bad doesn't change) all modes are available at any given voltage.

(Oh, my UF HD-2010 has the East-092 driver, if that matters any)

I'm prone to think that the 26650 voltage sags less under load compared to a 18650.