Sam, apparently these are the cells used...
lithium.jpg
Ian has been operating his facebook page for a while now with 7.8K followers/members and have seen him recommended on quite a few forums/pages...havent actually heard a single bad thing about him...
I asked what cells, connectors and BMS they were using in those particular batteries and received a link to his post explaining about the batteries...including the above photo of the cells...they also sell DIY battery kits using Sinopoly cells which along with Calb, Winston etc are the more popular chinese cells used by the "better" suppliers here in australia.....including Enerdrive, Fusion etc who charge a fortune for the same cells.
lithium ian.jpg
Website address and FB link for anyone wants to find out stuff for themselves rather then speculate..
The FB page is also very useful as many of the members there build their own batteries for many different uses....Quite interesting to see and mostly a lot easier then people think ...
https://www.fpv-power.com.au/What%20is%20FPV-POWER
https://www.facebook.com/groups/SuperCapAustralia/about