Yet another Sharpie scenario, getting to be all to regular these days…
Indeed……
:+1: 
Sorry about that, but I’ve only had my Q8 for a week, after a very slow journey from China, so am still quite enthusiastic about thinking of tinkering with it a little, meanwhile am enjoying it very much, in standard form.
This is after all a modding thread, for modder’s torch, so I hope free discussion of ideas, some good, some not so good, and some constructive criticism, is still allowed.
The significant improvements in the second batch of Q8s surely would not have happened without the feedback here, and The Miller’s co-ordination and diplomacy.
Now, if putting a charging/powerbank connection into it is such a bad idea, please would someone explain why, rather than just :person_facepalming: and we could chat about it ?
another port to have to dustproof / waterproof?
I'm having the 3D printing of the 5ar posted polarity protection parts done now: https://www.thingiverse.com/thing:2627854
If they come out well, plan to use only the inner ring in a Q8 to test/prototype.
I’m thinking either under the tailcap, or the clever switch that Convoy have which takes a snap-on (or is it magnetic ?) charging connector. But that wouldn’t work for powerbank output.
Certainly I don’t want dust/water sealing issues or little rubber caps with tiny lanyards that don’t really work and smell horrible, or weak micro-USB connectors.
Basically a 2.1 X 5.5MM connector in the centre of the tail PCB, with a probe to contact positive at the driver is all I need, and I think is easily do-able.
Unscrewing the tail cap is not a problem, it is nicely made, and a lot easier than unscrewing the tube, wearing out the driver ground ring, faffing about with loose cells, big heavy external charger, opportunities to mis-load cells into charger or torch, putting everything back together etc.
Wireless would be really nice.
There is very little space between tailcap and PCB.
There is enough for the panhead screws. Nor does it have to bottom out on the tube, as long as the o-ring is covered. And the connector could even be flush with the pcb, just drill a hole, scrape off solder mask and solder it in, if you didn’t have room for a thin locknut. An 8mm drill fits easily down the centre of the cells, maybe 9mm, so plenty of room to fit even just a 4mm banana plug socket, though that would not be my first idea, I think something like this might fit:
https://www.maplin.co.uk/p/21-x-55mm-single-hole-fixing-dc-socket-jk09k.
Smaller diameter connectors are also available, e.g. the two Nokia types, my favourites for reliability.
Or just drill a hole in the centre of the tailcap and make the connector externally accessible. Could be done neatly.
Just chucking ideas around.
Of course it’s doable but I have some doubts whether it’s noteworthy safer than just taking the cells out for charging. Btw. if the tailcap doesn’t bottom out on the tube but somewhere in the middle it might bend outwards. I experienced this already with the thick wire on the tail PCB for current measurement with clamp meter. But if you go on with this mod I’m interested how you build your probe for positive cell contact since I’ll perhaps need this for another project.
Not safer, just more convenient to keep the torch topped up. And the powerbank capability is what really interests me.
Probe for positive would be a Pogo-pin, or DIY version, even just a small spring. The nuisance is that there is that Q8 logo in just the wrong place on the driver, a little stud would have to be soldered over it, and a hole drilled in the middle of my plastic disc.
You can not put a charge board in the tail, simply because you have no connection to the battery +
The original groupbuy with 40$ was very tight calculated, so no charge stuff added
It would be interesting to see the numbers, wouldn’t it?
Including the adjustments that had to be made after the first round of QC feedback (and the benefit of no longer paying the salary of that guy they fired)
Presumably their bean counter left some elbow room in the cost calculation for fixing problems, since they must have known some problems would be found.
Yes I can, it is pretty easy to have a little probe to bring back +V to the tail.
Never suggested it should be standard, we have a fantastic torch for $40, quite unbelievable really. I am talking about mods, for the adventurous.
I know for use here, we need to target 25% or so cost vs. retail. And we work on very low commission and dealer discounts, like 20% or so. Our costs include labor and other overhead factors as well, but not NRE costs.
So if our retail price is $400, we need to keep the cost at or under $100. Dealers pay $320 - not much elbow room at all. Now we don't follow this rule all the time, usually our costs creep up to 30-35%, but 40-50% is the dead zone - we lose money.
I've seen/heard of one manufacturer, like Niwalker offer huge dealer discounts, like 60% or so, or more. So from their perspective, the money they make on sales is already discounted at 60%, so a retail $100 light is sold to a store at $40, therefore their cost probably need to be no more that $20, or 20%, but targeting $15.
NRE, sales/marketing, service/support are all extras, so you need enough profit padding to cover these things.
[quote=Tom Tom]
The way I see i, it makes no sense at all to introduce a connector that is not compatible with what is generally used for charging and discharging other devices. I don’t like the Convoy magnetic adapter for example because if I forget or lose that cord I can not do a thing.
A banana connector is a pretty standard device. You can solder or crimp a new one on a wire if you lose the chord. I think it's a nice mod. I charge mine in the tube anyway because I haven't bothered to buy holders. I don't know of any standard charging connector for "devices". There SOOO many, and banana is one of them, deans traxxas, power poles, bullets (bananas of various sizes), ec2/3, jst, standard laptop connectors in a variety of sizes, usb, and more. Fortunately they all involve soldering, crimping or otherwise clamping two pieces of wire onto two pieces of metal, not really neurosurgery and you can usually buy them cheap with wire tails already soldered, so then you can just twist, crimp, solder or whatever your skills allow those onto your two wires, or even just clamp onto them with aligators.
Anyway, if you're happy to unscrew the tail cap for access, it doesn't need to be waterproof.
Well, I am thinking typical consumer devices; like my phone, my tablet, my gps, my Canon powershot G7X camera, … They all charge via a micro-usb port. So if I want a flashlight with internal charging I want it to be via the same micro usb cord. That is how I see the situation. I want simplicity, universality or as close to it as can be had. If charging is by micro usb I can buy a new cord if needed in many many places.
Edit: …forgot the three bluetooth speakers we have that use a micro usb for charging. And my black diamond headlight.
I have a 3 panel Solar Panel from CottonPicker’s as well as 3 of his USB chargers. Each panel is good for 1.1watt, can run a 750mA charger with no problem. So there I have 3 18650’s charged in an afternoon of fishing, by merely harnessing the sun.