contact springs - sources?

LED Flashlights – General Info 18650 Flashlights
1

First post here, but I’ve enjoyed browsing here for quite some time. We have just a few budget cree lights, and I’m having an issue with one, that was a gift.

The unit is a low-end light, branded but novel in that it can be recharged by microusb and provide some power through regular usb. I’m curious how to identify the cree driver in it, and also where to find some new spring contacts for the center and external post of the head unit as they’ve come loose and separate whenever the head piece, or tail piece are removed.

2

Can you take a picture of them? Is it a p60? Mtnelectronics has small springs.

3

On most flashlights the springs are soldered in place. You should be able to re-solder the existing springs since you still have them. Often times the solder joints are either too small or of very poor quality on these lights, which makes them prone to breakage.

4

Thanks, I will check out Mtnelectronics. Right now I am using foil as the small spring and cap are very fragile, will also check Ace hardware over the weekend. The contact nearest the outer tube needs to touch the tube, so will need some kind of spring contact with a flexible base.

5

This light/charger has an odd head with a flat base, I think it might be a “Q5WD Epistar”, from specs here:

http://www.miumiulife.com/goods-315-Deal！LOFTEK+Outdoor+Portable+Flashlight+with+3+Models%3AHIGHLOWSOS+2600mAh+Backup+Power+Bank（Free+Shipping）+.html

btw, these are cheaper on amzn - ~$16.

The light appears to be well made, but not your standard sipik clone in design, the usb charger guts in the base and battery holder are one piece, they slide and screw into the base of the center tube. The head part then screws on the other end of the tube, so the contacts and grounding are using micro spring contacts to the +/- of the flat base head, pretty much directly from the battery top, with a ~1.5mm plastic keyed disc with two round holes where the battery contact solder joints are located.

6

Here’s a pic of the flat back of the head part:

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Was there something soldered onto that head? It doesn't look like it. Also, that's a little different design on that broken spring than usual, not quite sure what to say about that one. Can the plastic come apart?

8

Interesting, so the springs are on the battery side. My guess is that you will want to undo the screw holding the parts in the battery tube and slide it out. Post another picture then. The center spring came loose because of a cold joint(solder didn’t wet to both the spring and the pad). I’d want to make sure I was not going to harm something hidden before trying to fix the solder joint. You might be able to resolder it in place but it’s difficult doing it that way.

9

That I’m aware of, just contact springs, or center soldered pad on the battery side through the plastic insulator disc. I don’t think the red plastic insulator part will come apart easily, or was meant to, but if I can find some spanners, I’ll give the assembly a gentle nudge.

10

That sounds right about the center part, which may have been the little brass tub contact. I’ll try to take it apart this weekend, and take images of the battery assembly, and how the top black plastic thing is just a press on keyed ~1.5mm insulator over the battery connectors.

The design is pretty lame, IMHO to current round spring contacts in that rotating the base, or the head, will rotate the contacts, and in a ~$15 device, those contacts aren’t going to be high quality, permanently lubed spring loaded brass pads, thus the straight spring, tin caps came apart easily. But other than this weakness, the unit has some heft, and the high mode seems like 160+ lumens easily but I don’t have a way to measure that.

11

Some pointed scissors might also work to remove the outer metal ring and the red plastic inner one.

12

Both the inner and the outer rings on the back of the head are wedged in pretty tight, so taking that apart will have to wait until I can get some proper spanners.

I did make some progress though, and have pics, but will try to describe what my problems were after losing or having the original spring contacts come apart.

Reading the DCQ Tiny issues, where the back of the head center was not the positive had me getting the multimeter and wires out and verifying that the center is positive, and the outer edge is the negative. The body is not part of the ground.

The battery holder is attached to the screwable base with USB parts, and is very flimsy plastic, with both contacts soldered badly at the top, about < 2mm from pos to negative. A black wire takes the battery negative up to the top. The keyed black plastic disc was at one time glued to the top, giving some insulation, also leaves about 1mm of spacing between the top battery contacts and the holes for the spring contacts, which might be fine for circular, non squashable contacts.

The issue with my foil usage was that with no pressure of the head being screwed down into the tube, I could verify no shorting with my foil or foil/spring/cap parts and was miffed until today why it would sometimes not power on.

Well it turns out that the foil under pressure, very likely was shorting the battery under the disc, so with needle nose pliers, I formed the foil contacts so that both the center and the outer one, can rotate 360 deg. and not touch each other, and also twisted/keyed them so they would not likely fall out under normal usage.

A better solution will be to get some brass contacts and solder them to straight springs for both the center and outer part. I’m surprised that the shorting didn’t damage the battery, so there may be some protection in the usb bottom end. The non-protected laptop battery is still showing 4.0V and was used some. I’m currently doing a run down test to verify that the circuitry cuts the light out when the battery is down to ~2.5V.

Basically, there is not an easy way to properly shore up this design, if say I wanted a 100% reliable removable head and 100% working contacts. To do that, I’d need a couple more mm tube.

This has been fun, and I’m now not so sure I like the shortcuts taken in shorter lights if the insides are going to be weaker contacts. Will post photos, and info on the USB later, as I have a usb data thing coming from dx in a week or two, and photos of the battery holder assembly with and without disc on, next time I put flash card on computer. Thanks all. It’s still a pretty good light, and I don’t foresee the need to pull the head that often, so am hoping that with the next batch of lights and hacks going on, I might ultimately find some parts to eventually make this flashlight foolproof, in case I did want to swap batteries, e.g. use it as a charger, more flexibility, etc.

As I mentioned on the 18650 single ~$2.00 power bank review thread, In my experience with Android tablets, kindles, and a handful of phones, 1 x 18650 is not that usable as a power bank, but 2,3,4 + could be, for my uses. It’s still a bright light, no zoom, and good external build quality, a notch above the Sipiks, maybe like the condors.