Sofirn SP36 Double Click Firmware Crash Issue - Help Needed

Hello Everyone,

I recently bought a Sofirn SP36 as a gift. I bought some 18650 batteries as well off an online battery retailer. When I go the flashlight and tried the batteries in it, it more or less worked. Ramping up/down worked. But when I try to double click to enter turbo mode I get 1 bright flash and then the flashlight turns off (including the button, it’s no longer green). In order to continue using the flashlight I need to disconnect the batteries and reconnect at which point the green button is lit up again.

I tried a different set of 18650 batteries that I have and the double click works fine. So then I tried charging the original set of batteries overnight, but they still do the same thing.

Is the firmware crashing? Are my batteries no good (but then why does ramping work)?

Any help or thoughts is appreciated!

Would you purchased protected cells? High power lights don’t work with PCBs.

Sounds like protected cells having their over current protection tripped. This light should be used with unprotected button top cells instead.

+1 use unprotected cells.

Yeah, definitely go bareback with high-draw lights.

Thanks for the quick reply everyone. You are right, they are protected cells :confused: and here I thought I was getting the safer and better batteries.

Does anyone have recommendations for where to get best bang for buck 18650 batteries? (Ideally shipping in or to Canada)

Just for the record, I was using Imalent 18650 protected cells in both my SP36’s and haven’t had any issues. All functions worked as expected with no turbo issues.