HydrAxx & Barkuti, thank you for your very useful information. However, despite the presence on the market of good elements 18650 and ready-made cases for their installation in a battery for a bike (for example, e-bike battery case ), I select elements in the format 26650 or, as a last resort, 21700. For example, I encountered some unknown 26650, which also seemed interesting to me, but the question about them is still there without answers Test/review of Shockli 26650 4300mAh (Green) 2018 - #5 by volchyonok