Issue with spark SD6-500CW

I'm new to this forum but have lurked here for a bit. I have found a lot of helpful info here. Wanted some thoughts on this - I have the above light, it's about a year old. I used it fishing quite a bit with no issues. It might have been splashed but never submerged. The last time I used it the battery seemed to die. Recharged it, nothing. Ended up ordering a new light (zebra) and new batteries. Both the old battery and the Spark are shot, neither one work. New batteries in the new light, fine, old battery and new light nothing, and vice versa. Any ideas here? The only change was that I ordered and placed the reflector adapter just before everything died. At this point I assume its dead and I doubt there are any user serviceable parts. Thanks for any help.

Try 2xCR123s. What's the voltage on the 18650 before and after you charged? Do you observe Li-ion safety rules? Could have tripped the protection circuit on the 18650 - do you know how to reset it? Could have damaged the PCB as well (I broke one on a drop). New cell could be too long, or button top too flat, preventing connection/complete circuit on the neg/pos end, respectively, on the old light. Could be a faulty light, of course, these brands are only warranted for a year after all.

Don't know what I did. Whatever it was I killed both the battery and light. The light wasn't dropped ever, perhaps it got wet somehow. Don't know. On to different things.