New here, so just browsing the threads and saw your question. I don't have the Zulus V2 yet but have been eyeballing them pretty hard. I do vape and been through a lot of 21700 batteries. I have a drawer full of them that I've collected over the past few years. Right now I'm using Molicel 21700 P45B 4500mAh batteries and they hold up pretty well. I have 4 that have been in use since August 2023 and are still going strong. At 65 watts and heavy use, a set of two will run ~8 hrs and still be at 50% charge or more. FYI, there is a great ranking chart attached (testing by Mooch). Given that that's a much more demanding use case, I'd be comfortable using it to find a good battery for your optic.
21700 Ratings & E-Scores table