Hey guys I hope you can help me figure this out. Im just getting into LED lights and I bought a Creee XML T6 Ultrafire zoomable light and loved it. However I got the bug and wanted to modify it for fun and get a bit more bang out of it. I bought a nanjg 105c (2800ma) driver and installed it with no issues except its not any brighter than when I started. I even installed a second driver with no change. I measured the old driver at the tail cap end and at the LED and with a current reading at high of 1.2 amps. After changing to the nanjg Im only getting 1.45 amps at the same locations. Am I totally missing something here? I thought I would reach out to someone with a bit more experience than me before I float tested the whole thing. Ive used two different DMMs and two different nanjg105c drivers. Here are the links to the items I bought. Thanks for the help!
Nanjg 105c is a standard driver that should easily handle over 1.4 amps. Here’s some things to check:
1. Examine the 105c and verify that it actually has all 8 regulator chips attached. The 7135 regulator chips are the ones at the edges. There should be 4 on the top and 4 on the bottom. If there’s only 4 chips on the board, then you were sent the wrong driver. You’ll need to get another driver or add more 7135 chips yourself. Adding 7135 chips to a driver isn’t the easiest thing to do and probably isn’t a good choice for your first mod.
2. What brand of 18650 battery are you using? Many cheap 18650 cells are fake. Sometimes they have a very small battery inside an outer casing. This is common in xxfire batteries. If you have a fake battery it may not be capable of supplying sufficient power to run your light at higher current. I recommend buying only name-brand 18650 cells from reputable sellers such as Mountain Electronics or Illumination Supply. Non-fake cells should be safer too.
3. Check the electrical connections. A poor connection between the edge of the driver board and the pill (the pill is the little capsule that holds the driver and the LED) is a common cause of low brightness. The 105c driver has a gold ring at the edges on the top and bottom… but not on the sides. If your original driver made contact via its side edges, the 105c might not have a sufficient connection. To fix this, I usually file down a portion of the edge of the 105c and then solder a piece of copper solder braid to the edge. I bend the braid down so it lays along the edge of the driver for good connection. Alternatively, if your light has a brass pill, you may be able to solder the driver directly to the pill.
4. Solder-braid the tailcap spring. The tailcap spring on many lights is very thin and adds resistance. To reduce resistance take a piece of solder braid and solder it to the top and bottom of the spring. This takes some practice to get just right. If you don’t want to practice, you may be able to get a benefit just by wadding up some solder braid and sticking it inside the spring without solder.
5. Consider upgrading the driver wires. This isn’t the cause of your driver only supplying half the rated current, but it’s another thing you can do to reduce resistance and get more power out of your light. I prefer 22 gauge silicone wire. Illumination Supply and Mountain Electronics also carry this. It has the added benefit that the silicone insulation around the wire won’t melt like the PVC around the stock wires.
6. Check your modes - verify that you’re actually in max power mode and not an intermediate mode. Half-pressing the button without letting it click completely should let you change modes.
7. Check your multimeter leads - your multimeter’s leads may not be thick enough to carry more than 1.4 amps, giving you a false result. You may need to upgrade your multimeter leads to something thicker. One way to check if this is the problem is to compare the visual output before and after the mod: Do you think the light looks brighter with the 105c than with the stock driver? If it does, then it’s probably your leads. If you think output looks the same then it’s probably something else.
1 The driver does have all 8 regulators. 4 top 4 bottom.
2 Im using a recycled laptop battery which I know to be good and has a capacity of 2800mah. 3.6V.
3 I soldered the pill to the board.
4 The tail cap has no spring just a brass nipple sticking up Ive cleaned the contact point with emery cloth.
5 Dont have the readily available but will consider.
6 Checked
7 Ive got a pretty good fluke meter that can handle up to 20A but thats not to say that the leads are bad so I will have to check them.
Well I did what I could do and checked all the connections but still only 1.41-1.46 A. Could I have bought some suspect drivers?
Thanks for the
Under the brass nipple in the tailcap is a spring. To reduce resistance you could disassemble the tailcap and solder braid the spring, then reassemble it. You may need needle-nosed pliers to unscrew the switch retaining ring. However, I doubt the tailspring alone could account for the light only producing half its rated output.
Are all modes lower than they should be, or is it just on high? How good is your ground path from driver to pill to light body?
ETA: firelight beat me to it, partially on his #3
I soldered the tail cap as suggested but no luck. I just ordered 2 new nanjg105c from DX hopefully they will work. I just have to wait 3 weeks to find out.
If you want to insure you’re getting high-quality parts you might want to try Mountain Electronics. The owner, Richard, is a fellow member of BLF and he lives in the States so shipping is much faster. There are also many more options in what to choose.
I suggest the following:
QLite driver - this is a Nanjg 105c flashed with the Qlite firmware. I suggest sticking with the default 8 chips, so no need to add or remove. You may specify your choice of modes and whether you want a turbo timer. I prefer moonlight - 25% - 100% with 2 minute timer.
While you’re there, why not upgrade the stock XML LED on aluminum star to an XML2 neutral tint on a direct copper star:
16mm star with XML2 T6 3C
Mountain Electronics also has a wide selection of quality 18650 batteries to choose from.
What makes the laptop pull known to be good?
A 2.8 amp driver is a 2.8 amp driver. It's a linear driver and it will put out 2.8 amps. Out of all the nanjg style drivers I have bought over the course of many years, I have had only one fail and it was not due to low amps, but due to a faulty controller.
If you have tired two of them and they both read similar, it is not the driver.
Use another battery of different make, preferably Panasonic or Sony, or Samsung. One of the 10 amp batteries would be good. That way you know for sure the battery will deliver the amps. I would just about say for sure that the battery is only giving out 1.4 amps and that is the best it will do. I have seen this many times, with many batteries and now I only use the Panasonic 10 amp, or other high drain cells, even for 3 amps. It's just not worth the inconsistencies. Panasonic NCR, Sony VCT or Samsung INR. Mountain Electronics has all of those, as well as Illumination Supply, both are respected sellers. If you have 1.4 amps after that, then send it to me and I will troubleshoot it if you want.
What OL said about your battery is exactly what I was easing into. I don’t go so far as to use 10A cells for 3A applications, but your battery is probably not capable of the drain required for this application, at least not while also maintaining the voltage required.
Okay I might have been a bit too confident in my battery or perhaps didnt pay attention to which one I was using. I replaced the battery (Sony US18650S RG) I was using with a Samsung ICR18650-23A . I finally got the 2.8A. I thought I had a good battery as I used my Accel charger to drain and charge but, I had the specs confused. Even tho the samsung is only a 2300ma battery Im getting 2.8a at least I will for a little while. Thank you so much for all the input. Sorry to have bugged you guys with this and it turning out to be my battery. I thought I would try the recycled route just to save a few bucks until I really got into these lights. I guess now you could say I am “into” these lights now and into modding them so its time to invest in some good batteries. Thanks for the link to Mountain I was looking for a US seller to avoid the long shipping times (Im too impatient). All is good now and I learned a good lesson today. You guys take care talk to you later! Aloha
Good deal.
Hopefully you will not take offense, but it sounds like you need to learn a little about batteries: mAh is not a good indicator of available current, it is a measure of capacity. Hopefully someone will chime in with a good educational link: I’ve got to run for now.
Please feel free to offer some education or a link that would be great.
Does he need IMR cells to get 2.8 A? The internal resistance of a good cell may do a lot to limit the current.
No 2.8A is really not much demand at all, if a battery isnt capable of that I’d say its got some other issues (as in needs to be thrown out), even my cheap 16340’s and my eagletac 14500’s can put out 2.8A for a little while, for just about any 18650 2.8A should be easy especially when fully charged.
You can find plenty of good info here - http://budgetlightforum.com/forum/batteries/rechargeable
PLEASE do some research, Li-ion’s in untrained hands can quickly turn into bomb’s, I’m not saying that to scare you and I’m not exaggerating, they can quite literally explode if mistreated. Its not a problem to use them safely and I’m not trying to turn you off of them, the capacity/performance is unmatched but you really really need to know what your doing before you just start using them. I gave my buddy a setup last month but before giving it to him I made him do a ton of research and learn how to be safe.
Looks like a Panasonic 2.400 Ah drops about 0.2 V at 3 amps. O.11 Ohm, if I read the table right, which is not far from the same. You are right, that is less than I expected, much less important than the state of charge.
Cereal_killer is correct of course - I consider an 18650 that can’t give even 2A to be a cell that has reached the end of it’s life.
I can’t remember where I’d normally send people to learn about this stuff, and after a glance around I didn’t find anything truly great. Adafruit’s article on batteries seems accurate and mostly to the point though. It touches on all relevant aspects in terms of capabilities and capacities. You could also check the similar article at Sparkfun.
What’s probably not covered in depth in either of those is safety and the importance of a charger that terminates properly. Since you have a hobby charger I’m assuming that you already have LiPo packs to go along with it. Same stuff applies for both, safety wise. Don’t charge damaged cells. Don’t overdischarge cells and then charge them, don’t get cells to hot, etc.
Just out of curiosity, why don’t you use a fully charged battery?
Yours may not be as bad as some would tell you, if you just charge it to a full 4.2v…
I’m assuming you looked up the part number stamped on the 18650 to get the mAh number. It’s almost meaningless, except as a way of ranking different makes & models. Call it “Marketeering” as opposed to “Engineering”. If you care about “Charge” or “C”, the 2800 tells you your 2.8A driver would be pulling 1C out of the battery, which is a gentle load.
As has been documented thoroughly on BLF, while laptop pulls are a cheap, plentiful source of perfectly serviceable 18650s, there is never a guarantee any of them will be “good”. You have to charge them and test them yourself before you can Know. If you charge it fully and it still won’t give you full Current through your driver, that’s another sign it’s bad.
Also, be sure you clear the little weld-nipples off the ends, as those can prevent good contact…
How do you get “2800mah.”? I thought 2.4 Ah. is as much charge capacity as one can find in a 18650.
I spotted an error there. It says “Power Density: 126 Wh/kg for lithium ion, 185 Wh/kg for lithium polymer”. But Watt hour is a unit of energy, not power. Watt is the power unit.