Thanks Jason! I managed to get the pill(?) out by using circlip pliers but I have no idea how to seperate the driver board from the rest, so it went back in. (and the light still works!)
A neighbour had a DMM, watched the instructions on YouTube and measured the current draw a few times. A mixed bag really, as the numbers kept fluctuating quite a lot (because of moving a bit?), sometimes stopping at a number, pausing, then slowly creeping up in increasements of +1 until it stopped at about +15 from where it initially paused. Here the results:
1st. time: between 940 and 1060 mAh
2nd. time: between 945 and 1131 mAh
3rd. time: between 973 and 1119 mAh
4th. time: between 977 and 1128 mAh
So I’m really no wiser, because I have no idea how accurate that DMM (UNI-T UT33A+) was. 1060mAh seems about right if I look at the specs of a 7135*3 (1050 mAh), 1100+mAh might be a bit enthousiastic reading of the meter. Used battery was a fully charged Shockli IMR 18650 3.7V 3600 mAh.
Maybe somebody with a similar Convoy S2 Grey 7135*5 Driver 365nm Purple UV can chime in, open his/hers and have a look and tell me what he/she sees. As said before, I’m just curious, learning and trying to understand.
This is rural Thailand where labourers earn a meagre 300 Thai baht a day, the equivalent of just under 10 US dollars. It’s handed out in cash as many of these workers are neighbours from the village and/or have no means of transport, and if they already have a bicycle or a moped, the bank (and ATM) is several kilometers away.
So yes, at the end of the week 300 Thb x days worked (usually 6) goes in a small envelope and is mostly already spent before they even receive it.
I know, old days for many or us but here still standard practice.
To remove the driver you need a beefy solder iron because you need to heat up the entire pill and melt the 2 solder blobs. Then you add the solder blobs back when you put it back in.
I really wouldn’t worry too much about the output. They would not try to cheat you by using less 7135 chips as they cost almost nothing. Those UV leds can not handle much power anyway. As long as it’s bright enough for your usage, I would be fine.
It’s the UV led that costs some money. The 390nm/395nm leds are much cheaper and unfortunately some companies will try and pass them off as 365nm. You might want to verify the led and not worry about the driver.
I have a Convoy S2+ UV light and it is only .700 amp (uses no filter over led) and is plenty bright. I wonder why you are using so much power? Maybe they used a different led? Does yours use a lens filter?
Again, if it works for you, that’s all that really matters.
Nah, the quest for what type of driver is used stops here… Up till now I could change a battery, configure different modes (not this model as it’s just on or off) and all of a sudden there’s strange tools and a DMM on the table, and now I need to find a solder iron, beefy if possible? Nah, enough…
It is what it is, a handy small UV flashlight and I will probably never ever look into the ‘innards’ of it again. Yes, the output is more than enough (she says) and to be honest, when the light was lying in pieces in front of me, it took me a while to realise I was also looking at the LED, tiny as it is. No idea about the specs. But thanks again for the instructions.
Hmmm, maybe flat top “caps” are hard to find? Even button top caps are tricky to find if your looking to buy a pack of them.
A possible solution is to find a protected cell with the circuitry on the bottom, negative end. Then it is just a matter of removing the button top and adding a new wrapper. I don’t know if the total length is much shorter, though. Maybe at least 1mm shorter?
I’ve got my new XTAR PB2. I’ve noticed this ongoing theme; after using it to charge my phone, it’ll say something like “75” battery life. After unplugging my phone, it’ll jump to 68, or something of the like. I think this is from voltage shenanigans, but why exactly does this happen?
Similarly, when the powerbank gets low (say 30% and lower), when I activate the screen on my phone the powerbank seems to just shut off. The screen LED disappears, it stops charging, etc. After unplugging it and plugging it back in, it begins charging again, with the same situation as before - a lower percentage. I’m guessing this is once again voltage shenanigans; the phone voltage increases under load, it messes with the charging, and things get all funky. What’s going on? Is this bad for the phone/battery?
Lastly, how much efficiency loss should I expect? Let’s say I have 4000 mAh worth of battery in my PBS2, and my phone has a 4000mAh battery. In an ideal world, 1% on the PB would be 1% on the phone, but obviously that’s not the case. Is it closer to 1% on the PB = .75% on the phone?
Protected flat top seem to be more popular 3+ years ago, but are not seen so much these days.
I don’t know if you can really call it a “flat top” since it has a wide, but short button top. They have to connect the strap to the top electrode somehow. If they did not add a cap of some sort the end would not be flat. So they use whatever cap they can. You end up seeing wide and narrow button top and with slightly different heights. It is all a mess with no real standards.
It is trying to predict battery life based on calculations of voltage and load. This is very hard to do with accuracy. You can not expect good accuracy for predictions.
This stuff is very specific to the PB2. It has it’s circuitry designed a certain way. You’d need to ask the Xtar people these specific questions.
Hard to say exactly what the efficiency is, but I would not think it’s in the single digits of efficiency, but I really don’t know. Since the PB2 can output 5v from a single 4.2 volt battery it has to have a boost driver of some sort. Boost drivers do produce a loss in efficiency. I’m trying to decipher HKJ’s review and it looks like on battery power alone the efficiency starts at 90% and slowly drops to 85%. This sounds about right to me.
Also, remember that most batteries are rated for capacity by measuring all the way down to like 2.8 volt or less. The PB2 powerbank only puts out 5v from battery only until it’s batteries are down to 3.2 volt. So if you are using two 2000mah batteries you will not get the full 4000mah out of them (assuming they are wired in series, maybe not, but you basically can think of it as 4000mah). How much capacity you actually get will be based on the discharge curve of the particular batteries you are using. Some drop like a rock after 3.2v and some keep going a long time after 3.2v. I would probably use the newest, best high capacity cells I could, like Samsung 35E or equivalent in order to get the most out of the powerbank.
Sorry I can’t answer too exactly, but hopefully it helps a little.
In the case of lights with different emitters, because they perform very differently but the owners probably like all the other aspects of those lights.
Other people get them in different colors, metals, etc. which I don’t get but that kind of “collector” mindset is common for lots of hobbies.
