Warrior's driver design flaw

LED Flashlights – General Info
1

Recently I experienced strange behaviour from FandyFire Warrior, flashlight would power on by itself, buttons would become unresponsive...
Sometimes that would happen when I slightly unscrew the head (as a lockout) sometimes it would power on immediately after fully tightening the head. First I thouht that there is a problem with drivers outer contact ring (contact surface for negative pole). I cleaned the threads and driver thoroughly and it seems that the problem was gone but after some fiddling it was back and then again gone and back...

I could not find what triggers this behavior!

But after some more contemplating over the flashlight I finally found it and unfortunately, it is a flaw in design of the driver, more precisely: inner diameter of the copper ring that is used as a contact surface for positive battery pole is too wide and there is a trace/wire inside of this ring that is to close to the copper contact surface.

If you use batteries with wide and flat positive contact (flat tops) battery contact plate will make a contact between positive contact ring and that tiny trace and the flashlight will automaticaly go direct drive. I tested this by connecting my testing battery (it has soldered wires) and then making short circuit between + contact ring an mentioned trace.

Maybe picture will help to understand:

When flashlight was new this trace was covered with that white lacquer/paint, solder mask or whatever it is/was but after some use, batteries scraped it off and that was enough to cause this problem. It happens with Panasonic NCR18650A, Sony US18650GR, Samsung ICR18650 but it is very hard to repeat this behaviour, it depends on positions of the batteries.
I think that if mentioned PCB trace were shifted only 1-2 millimeters towards the drivers center this would never happen.

Here is how it looked when flashlight was new:

After adding a blob of solder on top of my testing batteries I could not repeat self-powering on, blinking and other strange behaviour.

I made a video about this but I didn't notice that my memory card is full so it's shorter than it should be but you can still see what am I talking about and you can test for yourself if you have this flashlight...

There are couple of solution like:

- use batteries with smaller + contacts
- melting a fair amount of tin on the positive contact ring so it would rise a contact surface/point over the surface of that pcb trace (not neat)
- soldering a brass or copper ring (hard if you have no materials or lathe...)
- cutting that trace in PCB vias with a drill bit and soldering wires on inner side of the driver (I like this one but the driver is glued in, so this would require good amount of force and could potentially ruin the driver)...

Anyone else experienced this?

2

Copper wire, bent into a circle the right size to land in the center of the cells, solder to driver.

Much easier to solder on the driver once, than solder a blob onto every single cell before it can be used in the light.

3

thanks for this info.my warrior does not have this problem yet, even with flat tops, but i will for sure keep this in mind.

4

So this is what you were talking about in another thread? Odd, I use/replace batteries in mine frequently and do use some flat tops, but no problems yet. Tks for the info. Maybe, hopefully yours is just “special” :wink:

5

Worse comes to worse, get some liquid electrical tape and paint over that trace, or clear nail polish (conformal coat)

I also wonder if a spacer such as a dowel rod (fat drinking straw) or even an unsharpened pencil couldn't be put between the batteries to keep them separated (they are really loose in the battery box)

6

Thanks Sirius9, happened to me once, just came on with no one touching it. Now I know how to fix it. Sad to hear my favorite light has a problem.

7

Thanks for the info and tips, normally use buttons, but have used flats , but they rattle a bit so back to button tops.

8

Some useful tips here, thanks.
As a least invasive method I used sponge, I shoved it in the middle between the batteries, since they are really loose as mentioned by WarHawk, that was enough to push them towards the outside edge of battery carrier and away from the drivers center.
Also, sticking XML insulation gasket (almost a perfect size) in the middle of the driver will work for NCR batteries but not for true flat top batteries because this insulation gasket is too thick (must be something that is less than 0.5mm) and prevents batteries <-> driver contact…

9

Good find and report. If I ever get a Warrior, I will watch out for this.

10

Yeah, mine is showing signs of wear and it won’t be too long before it could be a problem. Thanks for the heads up.

11

Anyone know where to find affordable 3/4 inch ID washers to fix this problem. Have spent a two or three hours looking all over the net and checked all the stores in my town, can’t find then in town and the internet prices are $5 plus per washer after shipping.

12

You're right, I just looked for copper washers made to be a direct fit for the contact ring on the Warrior driver and I couldn't find them anywhere either! |(

Just use 14-16AWG copper wire bent into a circle. It works and is basically free.

13

I make a solder blob on every new bare cell I get. Just takes a minute and after that I never have to worry about these issues again…

14

So do I on my flat tops. That also gives you the added benefit of the relatively soft solder “deforming” to mate with the contact surface more perfectly, increasing the surface area of the point of contact.

15

The driver is clearly designed for button tops. Proclaiming a design flaw when a problem appears caused by using the wrong cell format seems a bit unfair.

16

Then there should be a note on a product page like: “This flashlight must only be used with button top batteries. Warranty void if used with flat top cells.”
Also, there is more than enough space on inner side of the driver for that trace, they just had to spend a bit more time on testing and trace routing and this problem would never had a chance to occur.
Btw, problem occurred while using, among other, protected Panasonic NCR18650A cells, they are button top, they just have a bit wider “button”.

17

Or you can do it the way someone invented it for the parasitic drain on the Rook.

Just a circular piece of plastic with 3 holes, where the batteries would touch the ring.

18

FT at least informs you
“Powered by 3*18650 batteries (protected button top batteries recommended)”