I just purchased my first 21700 light, the Convoy S21B (xhp50.2), but I am not sure which 21700 battery to purchase for it because I’ve read that some rewrapped cells such as Sofirn and Vapcell are too wide and do not fit other similar convoy models.
What is the maximum accepted battery length? Would button top or protected fit?
I was eyeing the Keeppower protected 21700 but I’m worried that may be too long for both the s21b and for my charger. I’m also considering either a 5,000mah Lishen or a Samsung 50E but most places are out of stock on 50e at the moment.
My suggestion would actually be the BAK 5000mAh 21700, which is the cell that is included inside of 21700 Convoy lights.
Its performance at higher currents is better than the 5000mAh Lishen(which is important for high current lights like the S21B) and on par with the Samsung 50E3.
If you can afford that, you should definitely pick the BAK 5Ah 21700 over the Lishen one over at 18650Batterystore for example.
I have an S21A and it fits Samsung 50E and 50G. It also fits the Wurkkos 21700, though it is a bit tighter interestingly but fits and powers the light no problem.
Given that light shouldn’t be drawing much more than 6A from the battery (3A 6V driver), I doubt there would be any significant difference in performance between most 5000mAh 21700s.
There’s actually a non-negligible difference between the BAK 21700 and the Lishen 21700.
5% of capacity difference at 5A, which is certainly small, but not negligible, and its higher power capabilities should make it usable in more lights, especially since you have to derate the Lishen one if you want better cycle life.
I haven’t had any issues with any of my Convoy lights with cell thickness. I sometimes write the date of purchase on top of a stock cell wrap and then put a clear wrap over it to protect it (so cell is double wrapped) and never had problems in any of my S2+, S21A, S21D, 3X21A, M3-C etc.