Until a few months ago, I didn’t realize there was such active development and an enthusiast crowd for flashlights. Tons of great info here, even for a simple consumer like me.
So Far I have bought two BLF A6s (lost the first one on the first night of a campout, second never made it across the pond or was stolen in transit) and a Nitecore MH20.
Since I am A6-less, I had been using the MH20. I finally got in some new INR18650-30Q (my first pair was cannibalized from a Wal-Mart power bank and worked flawlessly), ordered from BangGood (via Switzerland I think) and charged them on a XTAR VC2 Plus Smart Battery Charger (also from BG, used for the cannibalized batteries no prob).
So the first time I put the INR in my MH20, no worky. It has a button LED that will flash to tell you the battery voltage (reads 4.2V). After the battery is installed, the main LED just has a faint glow. You can tell it is powered, but it is less than moonlight mode. When I soft touch or hold for the highest setting, it will get a little brighter, but only as bright as maybe how bright the original normal first setting is. After I cycle through all of the modes (4) the main led is always illuminated super dim (eventually runs battery down).
I made a video and posted on youtube, but I don’t think I can post links yet.
Anybody had a similar experience or any advice? I am currently negotiating with BG to send me the second A6 that never arrived and will likely order another (I really liked that thing!). I got a RMA number from Nitecore, but have to mail it back to something something Glorious Tower, China, and I am doubtful it will ever get there. I didn’t keep any of the packaging because I expected this thing to last for at least a few years.
I think your cell is a flat top and most new nitecores use a reverse polarity disc which requires a small button top cell to make proper contact.
You could double check cheaply for proper function by buying a couple of cr123a,s,- might save a lot of return hassle.
yes 30Q is flat. My MH20 would not even light up a bit if using 30Q. Try different 18650 or just try two CR123 for testing.
Or you can put a solder blob on the positive end of 30Q. . Be careful and quick so you do not heat up the cell
I don't think a flattop cell would cause the behavior detailed in OP. It's making contact, indicating 4.2v and turning on, but almost acts like it has low voltage.
My Hc50 will do moon and low low modes when on very low voltage.
I would definitely use a button top cell charged to 4.2v (double checked with a multimeter) just to rule out those variables though.
In lieu of solder ball, I made a little button out of foil for testing and got the same result. I think something must be cooked on the PCB. It does measure the battery Volts properly and indicate on the button LED, so I think continuity is good.
Oh, and checked 3 good flat top 18650 (2 different makes) at >4VDC, all same result.
I think it is driver, I had Nitecore P25 acting the same way, but Smilodon is larger light, that driver has inductor coil that broke off of the driver and caused identical behaviour.
(I have a thread about repairing P25 driver but unfortunately all photos are off line because stupid image host that I was using for years all of a sudden decided to not to be image host anymore and deleted everything I had ther without warning |( )
Sounds like a bad connection somewhere. Try a button top battery - any Li-ion button top. Instead of foil a better solution would be a small magnet. Without an actual button top battery it will be tough to say for certain if it is the battery or another issue. I have a few of the Nitecore and a couple of them will act the same way with the flat top batteries when in fact they should do nothing at all.
With my limited knowledge, it does sound like the driver is not doing its job.
Whats weird is I was using a flat top battery in it just fine before it gave up the ghost. Switch battery, quits working, acts same with original or different battery. I did read that you have to play battery roulette sometimes, but it was working initially for at least 5 battery cycles.
What is the function of the oblong contact surface to the right of the (+) terminal? Is that part of the reverse polarity protection?
I think the lens cap is semi-permanently attached, and I don’t want to destroy this thing taking it apart since I have an open RMA (and I’m more of bigger the glob better the job kind of solderer anyway). Looks like this fella is taking a trip back to the motherland. Thanks for the help folks!
Yes, purely a physical barrier that rises slightly above center + contact and prevents flat - side of the battery to make a contact with + on a driver pcb…
