Is there a source for higher current switches for the Convoy S2+ and P60 type hosts? I’m trying to eliminate voltage drops and keep coming back to the low current capacity of the switches as a probable source of resistance. Even the ones Convoy sell as “high current” are only rated at 3 Amps by the manufacturer. The LEDs/ drivers in question will pull 5+ Amps when out of the host, but the brightness takes a hit once back in the flashlight. I’m using decent quality Samsung / Murata cells capable of supplying that load.
I know it’s popular to bypass springs, but I’ve already verified the stock springs on the drivers aren’t the cause in both cases, so I’m thinking the tail cap spring is unlikely to be much of a problem either. Resistance between the pill and host body could possibly be adding to it and between the tail cap and body.
I have wire Bi-passed a truck load of stock springs — I have verified with a clamp meter and my light tube that the rear spring is a cement dam blocking current ---- The front spring on the driver causes issues also — I have several S2+ Triple lights that draw well over 16 amps with the stock switch — There was a guy on the Forum that use to sell special springs — Good luck finding a better switch
I’m wondering how are you testing the Amp Draw and how much is it suppose to have vs how much are you getting
How did you measure the stock spring resistance? I’m pretty sure bypassing the spring is much more beneficial than replacing the switch.
I was curious and measured the spring and switch on my M21B and total was 25mΩ. I just completed a spring bypass (using desolder braid) and after it measured 10mΩ (with switch installed in tailcap). I measured using an AC IR tester and also verified the accuracy by putting 5A through it and measuring the voltage drop (using a separate bench power supply and DMM).
I also measured 5mΩ directly across the switch of an S2+ so there’s not much to be gained there by finding a different switch. However, if the switch is old and has a hard (high current) life then it might be worthwhile changing out the switch.
Using the AC IR tester I measured 0.35mΩ from the brass retaining ring of a shorty S2+ (18650 tube was too long to get the probe down) to the end of the body tube, so I wouldn’t worry about that.
Depends on the driver. In my case it was on an M21B with GT-FC40 so a boost driver. There would be no lumen gain with bypassing the spring, only less energy wasted heating the tail cap.
Example: running at 100% and battery at 3V it’ll be pulling about 10A. So, by saving 15mΩ I’ve saved 1.5W of wasted energy (about 5% efficiency gain).
Remember that these switches are rated at that amperage but also a much higher voltage. Visit the Omten site and you’ll see that they’re all basically the same rating there, and we know that they are decent enough to handle that many amps and some more. The metal-to-metal contacts are held pretty firm under compression from thread forces so that’s not really an issue. The driver circuitry and led wires may be the attention points…spring bypass if you like but that’s not really enough to bother with it imho, but if you did that and could use a heavier gauge led wire (and as short as possible) you can eek out some gains there. I don’t think there’s a better switch for the S2+ really…but I could be wrong…don’t recall hearing about anything in the past, though. It’s kind of a niche application where we need small clickies and high current.
You may be referring to @BlueSwordM . He had a batch of BeCU silver plated springs that are very good. He did some tests that showed they have less resistance than some bypassed copper springs.
I got some from him … maybe a year ago. I love them. PM him if you are interested.
Actually I may do that. I am due for more if he still has them.
I didn’t measure the resistance per se, it was more a process of elimination.
The flashlights both appear to be drawing around 3 to 3.5 Amps, with associated lack lustre outputs. Both pills have 5 Amp drivers, one an SST40 and the other a triple XPL-HI set up (parallel.)
I removed the pills from both flashlights and connected them directly to a 5 Amp 4.1V power supply. I used a short length of wire to make the negative connection and placed the driver spring directly onto the positive banana terminal of the power supply. Doing that both pills were significantly brighter and both topped out at the power supplies 5 Amp limit. So, in this case the spring on both pills appear up to the task. The switches on both have the same gauge (or heavier) springs in the tail cap. So I’m not straight away suspicious on their suitability. I realise you’ll get voltage sag with a battery (and a slightly lower voltage), but I don’t have a set up to test the current easily with a battery.
So straight away that’s clearly under rated for the task- hence my question. I’m not sure if that’s the standard switch fitted in the S2+ or if it’s an even lower spec stock? I haven’t pulled the tail cap apart.
I do need to do more testing, but the switch spec raises a red flag. Probably doing the power supply test at again at slightly lower voltage steps to see how the driver current drain responds would be a good start. But I’d still like to see if there are higher current switches available than the 1288.
A good test to do – Use a short piece of 14- 16 ga wire on the tail end of the tube — this way you’re taking the switch out of the equation — this will give you a reference to know how much the switch is restricting your current — I have several clamp meters, that’s how I check amp draw-- not with a power supply
Yes, I simply used the power supply to verify the driver/ led combo (in the pill assembly) was able to meet the max output specs within the battery’s voltage range. That verified they can hit higher brightness levels at 4.1V .
I have used a piece of short heavy wire to bypass the tail cap (without a clamp meter), but when you’ve only got the tiny body barrel lip width (that is not anodised) to make the electrical connection. It’s not the best set up.
I’ll try some more testing though to isolate what’s going on.
I think you may be trying to reinvent the wheel here. Several people on here both tested and/or reported mod results back in the day and the 1288 handles 10amps all day long just fine…provided it hasn’t been damaged in soldering and the spring is up to snuff. If memory serves, Dale and TA and some others had them around 20amps and higher and they were doing just fine…probably wouldn’t handle that for long sessions, though, not sure. I think it may have been djozz that had them at 16amps on a bench test for some hours without issue. Their resistance doesn’t change appreciably, either, which was a nice surprise. The rating you see has more to do with a safety spark gap. That said, these aren’t the most robust switches and the plastic housings are the weakest link (they do use nickel plated contacts, though, which is good for longevity vs. bare copper).
I don’t recall if they’d fit into an S2+ tailcap but they seemed to fit C8 popular at the time, but someone had some special switches for sale (Toffy maybe?) but I think they were only good for like 6-7 amps or thereabouts…defintely were made “better”, though.
When we mostly had cruddy springs to use, the switches suffered more and we also had more spring failures as they’d collapse or even melt, and sometimes that can melt/shift the switch housing but the internals are robust enough for just about anything we throw at them and the resistance isn’t so bad really. Thankfully we have much better springs now even if they aren’t the great ones. Also thankfully, the really cheap-cheap switches are almost a thing of the past in the lights we buy (still out there, though).
That lead onto Judco switches which can be easily modded and may possibly be made to fit (rated at 10 Amp.) They’re also readily available off Digikey. Modding a Judco Switch Something to maybe look into.
I did find some daggy rough edges on the switch’s circuit board so filed them off and clean everything with some decent contact cleaner/ lubricant - including a drip into the switch itself.
I was getting 5 Amps (limit of digital power supply) powering the head/ pill assembly off a power supply at 4.1V. I retested and that was stable down to 3.55 V , at 3.50V I started getting some current drop off.
I reassembled the body onto the head and used a Murata VTC6 cell with a wire loop and clamp meter and got 5.45A with the tail cap removed. (The wire wasn’t central in the clamp meter like you’re ideally supposed to have it for these readings.)
I then tried to measure with the head detached and the clamp meter wire bridging the body (with battery/ tail cap fitted) to head/ pill - that was hard to do and was in the 4.x Amp range. But I couldn’t get a good reliable connection… as I was trying to maintain the pill spring to battery positive connection and didn’t want to short out the battery!
It does seem to be performing a bit better- perhaps cleaning up the tail cap, PCB dags, lubricating the switch and the various connection points helped a bit?
PS: Why does the forum convert Aliexpress links to German!
It’s AliExpress and their country specific links, not BLF.
If you post an AE link with a “.com” and an “i” instead of “item” in the URL, then that is supposed to fix the problem.
I know it’s not a very convenient fix, but AE’s site is royally fouled up.
Half the time, especially if I’m not logged in, ali will change the displayed language to Russian or Spanish or Sanskrit. Happens more when I’m using multiple tabs instead of just clicking through on one tab. As big as they are and for as long as they’ve been a giant e-commerce force, their site still has tons of quirks.
smurcod…yes, Tofty. Been a long time. I don’t think anyone has come across a better switch for these yet, something that will work in tailcaps anyway. I wonder if Dale ever did more exploration here. I guess we don’t have to push cells as hard as we used to, with advances in cell chemistry lately, but the emitters and switches…yeah, beyond their ratings a little or a lot.
Is there any way to tell if you’ve got a genuine Omten switch?
It turns out the Kaidomain P60 host has the same size/ looking switch but neither it nor the S2+ have any visible part numbers/ brand on the switches. (Unless it’s on the bottom and requires desoldering to see?)
Been a long time. I don’t think anyone has come across a better switch for these yet, something that will work in tailcaps anyway. I wonder if Dale ever did more exploration here. I guess we don’t have to push cells as hard as we used to, with advances in cell chemistry lately, but the emitters and switches…yeah, beyond their ratings a little or a lot. 