Around 9.5kWh capacity LTO chemistry
The battery pack was designed so I could have started off with 55cells (5kWh) and later expand it by slotting in upto an extra 44 cells at a later date (when I had more coin), I managed to come up with the coin for a full pack for the build.
Batteries seem solid, although I have seen occasional reports of these batteries venting online. I'm not sure if it was from abuse or design/manufacturing flaw. Will keep you updated with performance of these.
*** am thinking about doing a group buy from a bulk distributor to get the cells at a discounted rate - let me know if interested***
(Update 28/10/20: I have had problems contacting a supplier that I purchased my batteries from. I managed to get hold of them today. The person I dealt with had left so my emails were going nowhere. If you are interested in a group buy for significant discount get in touch firstname.lastname@example.org I will be going through the details of this with the supplier this week and will be in touch).
Unaffiliated aliexpress link that I purchased my cells from. Please let me know if you have any trouble with battery capacity from this seller.