After looking at a lot of flashlights, mostly on this forum, I decided to purchase a UF-980L. I got it today and initially put a battery in and let it run for some time (probably 10 or so minutes) just to see how hot it got on high. Worked fine the entire time. Everything seemed ok until I changed the battery out.
I initially put one of the batteries i received in without charging it (bought the batteries new as well, this is my first 18650 light), just using whatever charge it had. Really only ran it for that 10 minute period on high, and had no issue. But now I do. Once I put the fully charged battery in, the light won’t stay on high for more than about 2 seconds. Although it does vary. If I leave the light off for a while it may go as long as 6 or 8 seconds before it turns off. On low or medium it seems it’ll run indefinitely. This happens on either battery.
Once it goes out, if I tap lightly to change the mode the high beam will come back on, but only for a second.
I’m probably going to contact manafont about this, but wanted to make sure I wasn’t dumb before I do.
I purchased a ultrafire charger wf-139 and two protected ultrafire 3800mah 18650 batteries. This behavior happens with both batteries consistantly.
Did I buy the wrong batteries? Could this be the switch failing?
Eric, unscrew the battery tube and make sure the pill is tight in the head. Mine worked loose after a few weeks and I had to tighten it. It only needs to be firm, don’t overdo it.
Likewise, check your switch is installed correctly and is firmly threaded in.
To test your tailswitch, remove it and with a cell in the light, connect a wire or screwdriver tip from the -ve flat end of the battery you can see to the threads on the side of the battery tube. This effectively becomes a switch. If this works and the light functions normally, then your switch is defective.
Another possibility is that on full with high current draw, the battery protection circuits are clicking in.
The switch is bad. As you suggested I connected the negative and the tube with wire and the light stayed on for longer than it would with the tail switch screwed on.
Do you know if manafont is good about fixing things?
Thanks again!
EDIT: Is there somewhere I can just buy a replacement from a reliable US supplier?
Junk batteries, my opinion. The UF980L pushes cells to their limits. I have a couple of batteries that do the same thing(gray trustfires).
Fully charged, the UF will pull a lot of amps from your cheap cells, causing them to sag below the protection circuits low voltage cutout limit.
My gray Trustfires did the same thing. If I bypassed the switch with a wire, they would stay on longer but still trip the overload after about ten seconds instead of a couple of seconds. I chalked this up to high resistance in my bypass method. All I know is that when I used good cells, I never have this problem and I have tried a lot of different batteries in my UF980L. Only the gray Trustfires would do exactly as what you describe.
I would still dismantle and check the tailswitch assembly before I went any further. It’s easy enough to do and should eliminate poor assembly as the problem. I have had several lights that were either poorly assembled, or came loose in transit. A quick dismantle and reassembly often fixes a problem. You only need to go as far as all the threaded together parts.
Eric, do you have a multimeter? If you do, you can test your switch for continuity with that, although a switch can behave differently with a small current verses a large current draw.
If it’s none of those things, then as fnsooner suggests, it may likely be your cells don’t like this light. Do you have any others to try?
Wow, I think I had/have two separate issues! lol. I had taken the light apart and put it back together and it was still behaving the same way.
So I buckled down, and made sure the switch was super tight in the tail and now one battery seems to be working just fine, after several minutes the light is still working fine. However, the other battery will hardly work at all, sometimes not even a full second on high.
I think I’m at least fairly confident the switch is ok.
Thanks for all your help!
BTW if you don’t mind, could you guy recommend some batteries?
Ok, that pretty much confirms its the cells. Probably fresh off the charger they are tripping the overcurrent protection. After a while there is enough voltage drop to let them work without tripping it. You may not need new cells Eric, just let them sit a day or two after charging before using them.
As for which cells are good ones, I will let the experts answer that chestnut.
You have a very nice light there. I hope you sort it out soon and enjoy it. I love mine, it is by far my favourite torch.
You probably need to head over to the battery section and get some recent opinions. I went on my battery buying binge last fall and winter and am not up on the latest, greatest and best buys of late.
I have had good luck with theTrustfire 2400mah and 3000mah flames sold at Manafont. YMMV
I just thought of another possibility Eric. It could be your cells are a tad too long and are putting too much pressure on the protection circuit board, the driver or even the switch contact.
I have not heard of this issue with th UF980L, but it has been a known issue with some lights and cell combinations.
Try unscrewing the tacap a little and see if that helps. As long as you have thread contact the light should work as normal, unless it is a lockout tailcap design, which the 980L is not.
I'm not saying it's not the batteries but a 980L's bezel, reflector and pill have to be seated just right for everything to work. The pill will thread right out of the head in either direction and on some lights, you can't simply snug it against the reflector and call it good.
I devoted some attention to this in my review. https://budgetlightforum.com/t/-/2284 It is very, length sensitive on the inside, I suppose you could say. If the pill is seated too deep or too shallow, it will change modes at will or not work at all. You might try screwing the pill in or out a little.
I have similar poroblem and I think that those 2 contact on the switch (inside tail switch), dont contact the body of the switch very good, so a small blob of solder on these parts woudl solve the problem, I think.
