Assuming you’re not talking about PWM, then it sounds like your light has a bad driver. Return it or exchange it, if possible. Or make sure everything in it is tightened well.
I have a 21 LED UV light that works fine with Alkalines but flckers like crazy with fully charged Eneloops. I have several electronic items that won't tolerate the lower voltage of Eneloops unfortunately. Eneloops are great from many things but really bad for others.
Yeah, it’s probably the lower voltage. Unfortunately, even though NiMH has been around for decades now, we still have to deal with products that are Alkaline-only and can’t handle a slightly lower voltage. :person_facepalming:
I just looked at a few of the reviews on Amazon. One of them said it flickers for about 10 seconds on high when using NiMH then it stops. How long did you leave yours on (flickering) before turning it off? I’m wondering if yours is the same as that reviewer or worse.
According to this thread, Sofirn is rolling out a new version of the SF14 "with DTP MCPCB board, better anodized shell, and more reasonable construction and more stable performance." It is available for purchase on Amazon right now. Maybe this update addresses the anomaly.
I just received a SF14 this week from Sofirn’s official store on aliexpress.
Mine also has the flickering on ‘high’ while using a NIMH. In my case the cells are Ikea LADDA 2450. I don’t think my flickering is as bad as what the OP described. Sometimes it is brief and then stabilizes again.
I’ve haven’t had issues using alkaline AAs. I even put an old alkaline that showed 1.25v on my DMM. No flickering. I thought that was strange considering my NIMHs had higher voltage than that.
14500s are fine.
I really like the light. Even with the NIMH problem. It might just be my new EDC (with 14500)
Okay, it’s starting to sound like a design problem.
Perhaps it isn’t as bright on alkalines (due to huge voltage sag), and so it won’t flicker. Flicker might just be a problem when it’s trying to maintain max output (which it should be able to on NiMH, due to lower voltage sag). In any case, this sounds like a problem with the driver they chose to use in the light. Poor tolerances? Poor QC?
I’ve been in correspondence with Sofirn through their Aliexpress store. They have been helpful in discussing a way to remedy the issue.
They have also added a listing specifically for the SF14V2 (mine is the V1 apparently). Physically it looks the same. The differences that I can spot are that V2 is printed next to the logo and the anodization seems to have a glossier sheen.
Mine arrived just Wednesday…. the flickering doesn’t stop — it is not usable on high.
I do NOT see a V2 anywhere…… disappointing that Sofirn would send out an older version AFTER they have produced a new one to deal with this serious defect.