I use this case with 8 x A123-ANR26650m1b cell. See specification attached.
The cranking power is 240A and the maximum charging is 20A up to 14.6V. 4s2p
(A123 recommended charging voltage is 3.6V /cell. If having long periods constant charging the voltage should be lower but that should be fine. I monitored my battery for 3 years by measuring voltage and temperature. If motorcycling 24/7 you might want to measure the heat produced. Similar link: http://liionbms.com/pdf/a123/charging.pdf)
Voltage regulator on my bike is 14.4V.

Use a 4S balance cable for maintenance balancing of the cells once a year. I use the Imax B6 charger. There is a flat cable opening in the case for this cable.
Glue the battery case together and make sure cables and cells are secured inside the case.

Weight is about 750g (standard led battery 12Ah on my bike, Duke 390 is about 3.36 Kg)
L = 111, W = 57mm, H = 83mm
Use high load cable and connector from this battery. I use the XT90 connector rated 90A continuous load. (I later removed the connector and use rings connecting directly to the default bolts.)

WARNING!! - I recommend you have soldering skills on lithium batteries and knowledge about the danger using lithium batteries. Or willing to learn by your self. There are lots of knowledge on YouTube and forums. The LiFePo4 is however the absolute most safe lithium cell on the market and fits the motorcycle perfect.

If you often starts the bike in very cold weather the tip is to turn on the headlight for 1-2 minutes before starting the bike to warm up the cells. If a every day start around zero C degrades is the case the led battery type is preferred.

Edit: made a 4S version here https://www.thingiverse.com/thing:3461006
Edit: made a 16S version here https://www.thingiverse.com/thing:3707791
Edit: made a 12S version here https://www.thingiverse.com/thing:3714356

Edit: Started the bike this spring 2023 (7th year) and the voltage was over 12V still. Amasing battery!

Edit: Summer 2024, still going strong!