Started my XHP-70 flashlight - EDIT: complete redo

Cool! this really gets the creative juices pumping…

Nice use of the drill pack :slight_smile:

Very nice concept. Should look pretty decent in black ABS. What size diameter driver you would like ideally?

EDIT: Not a driver expert. The FET BLF drivers work with the zener diode mod or with a voltage regulator chip like Rufusbduck did to a 105c way back. Are you going to go momentary switch?

Yeah, momentary switch. I suppose any size driver will work, I just need to know exactly which one or which parts.
I think the zener mod is merely a simple, crude regulator for the MCU. With 12V in the zener shunts the power input to the MCU so that it is not over volted? Normally the zener mod is for 2S builds, but this is 3S. Will that zener have to work too hard with the 12V in? etc, etc.

What’s the fully charged voltage of the packs? The XPH 70 has a Vf of 12.5V @ 2.1A so to get 6A you’ll need a bit more voltage. Simplest might be an Zener modded FET driver from Mtnelectronics though a bit more than a 200ohm resistor might be in order. A buck driver needs a volt or two over Vf to deliver the goods so that would require a bigger battery(like 14.4V). With a decent switch you could probably skip the driver completely but it’s unlikely you would see 6A. For that you might need to go to an H6flex and 18V input.

!0 out of 10 for creativity and execution. I've been using this 5 amp driver with 3 26650's getting about 4.7 amps at the led with the led on a 6 volt star. If you want to run 12 volts at 5 amps that would be double the current (edit should be wattage) that I am. Wowsa.

http://www.lightmalls.com/5-2-12v-5000mah-dual-lithium-3-mode-led-circuit-board-for-cree-xm-l-t6-u2-sst-50-mce-ssc-p7-leds

Fully charged these packs are 12.6V but that would drop relatively fast. For some reason I thought 12.6 would greatly over driver this LED. I just searched for a graph of VF and current and can not find one. All I can find is 11.6V yields about 1A. If what you say is true then I am SOL, unless it is possible to use a driver to run at 6V. I don’t know it there is a driver that can run on 12V and drive at 6V

That’s good news, so there is a way to drive at 6V with a 12V pack.

First things first, I will do DD with a partially discharged pack and then try fully charged packs and see what I get. And all along up until now, I was worrying that DD and a 12V pack could blow the LED. :frowning:

The second sticky in the first general forum thread LED Flashlight - General Info is Led’s & OTHER STUFF . Bookmark it.

The HX-1175b can drive a 6v emitter with 3s and 4S li-ions. RMM and others have had issues with it blowing 1S XM-L2's over like 5 amps.. I don't know if that is because it was bucking all way down to 3+ volts or if it continues to ripple at higher Vf's. I've driven 1S MT-G2's beyond 12 amps without issue, but we all know that MT-G2 is one tough hombre.

Did I read that right?

you have driven an MT-G2 over 12 amps with a single cell? aka 1S
did you use a boost driver to get the voltage up?

I guess it was an IMR/INR cell?

I think in this case the 1S refers to the led. The driver is buck and is fed by 3-4 series liion cells.

^ RBD has it right. 1S emitter driven by 3S or 4S cells. No boost ability. Sorry for the confusion.

The driver's flyback diode is only rated for 10 amps. So I recommend only driving up to that level. That would be equivalent to about 5 amps with the emitter in 12v configuration.

Could a hobby charger be used to charge up the packs you plan to use by just connecting the positive and negative terminals?

That enable adding a port and charging in light if you didn't want to pull the pack often You could just also solder the tabs for a real good connections. I'm asking because I have a couple of these battery packs too, but no pack speciific charger for them. I do have an Accucell 6 though.

Most of these types of packs have a tab for temperature sensor. It would be cool if that could connect to the hobby charger too. I'll give it a shot in a bit.

how about using this driver for the LED?

wasn’t entirely sure how much amps you need but a regulator like this should work?

^ That does seem like an interesting idea. Maybe 2 of them. One for each channel going to the Emitter. Could have external pots for them to control current.

Hobby Charger Update: The pack can be charged by a hobby charger just connecting the Pos and Neg terminals. All 3 banks fully charged to the exact same voltage. Don't know if that is due to internal balancing circuits or just luck due to new cells.

It appears that the center terminal between the Pos and Neg terminals is for the temperature sensor, but I'm not sure how to connect to my hobby charger since it has 3 wires (Red, Black, and White) for temperature monitoring.

The battery pack has some other terminals that I don't know the purpose of. No voltage measures at them.

It’s possible the eBay buck regulator is not current controlled. I. E. You can set the current and voltage for a given input voltage with the pots but if input voltage changes as with a draining battery, then both output current and output voltage might change. I don’t know for sure and they sure are cheap but you might consider testing one before building the guts of the light around it. It might work anyway but just not maintain regulation. Or I could be full of it, I often am.

I am waiting on solder paste to flow the emitter. I will then take some reading of current draws and post them here. It looks like I will have to rethink this setup somewhat (I figured I probably would)

I restarted this build from scratch, Using black ABS and eventually a buck driver.
I posted the changes in the OP. The light is finished except for installing the driver

Nice changes. Looks good.

PM'd you to work out the details on driver specs.

Nice build!
The Ultrafire name drawn on should give it and extra 20,000 lumens.