We can assume that giving it a fresh charged battery will set it straight every time? To me that says we have a battery (capacity) or charger (not charging fully or correctly) issue.
Do you have more than one battery or another charger? This is a Persei, don't you have a pair of 18350s?
OF
I have the original single 18650 and the two 18350s that came w/ the kit. No extra charger or batteries yet.
The 18350s sometimes flicker, but nowhere near as often as the 18650.
I found a multi-meter I can use, what should I measure (and how, haha) to figure out the problem? Should I do a volt test on each battery before or after charge, or do I test the Persei top itself with the batteries in? Not much experience with MultiMeters.
And, to add to this pathetic plethora of questions, I saw earlier in your posts to FriedBanana about mixing batteries; could my problem be that, for a few weeks, I was using the two 18350's separately with my short SS tube? I assumed that if I charged them in tandem, the volts would eventually match again, I'm feeling like this is majorly wrong now.