Round and round on the design of my battery system, and a lot of learning along the way.  

Current battery plan is for a 144 volt system.  Looking to use 42 Nissan Leaf modules.  While these have longevity issues, this is not a daily driver for me, and long range is not super important, the price was right.  Lead acid is out in my mind, buy Tesla modules were crazy expensive, Chevy Volt were too oddball for my config, and other battery types (CALB, LifePo ext), where just too expensive.  So Leaf it is.  I wanted to get to 144 volt to make sure my top speeds were well above 60 MPH, and 2 in parallel gives about 20KWH of power.  A quick back of the envelop calc -- 4 miles per KWH = about 80 miles of range for this pack.  Considering this is for fun, and I want to be heavy on the throttle, if I can get half that 80, I'd be very happy.

Some good data on a thread I stared at the DIY Forums: https://www.diyelectriccar.com/forums/showthread.php/leaf-battery-bms-202363.html

Long story short, need to be careful with overcharging lithium cells, so that must be considered when planning the wiring system.  This is a great document noting the benefits and drawbacks of different configurations: https://www.orionbms.com/manuals/pdf/parallel_strings.pdf

So, the final plan (at least as of today), is a 42S4P configuration per the following schematic:

24 Modules will go in the back seat area, and all be wired to the Controller portion of the BMS.  This maxes out the BMS connections.  The balance of the modules (18) will reside in the trunk, and be connected to the Satellite BMS.  So each "pack" location will have it's own BMS.  Putting more modules in the back seat, would require wiring from the Satellite BMS to both the back seat area, AND the trunk area, complicating wiring for sure.

BMS: https://www.thunderstruck-ev.com/bms/

Charger and DCDC Converter spec TBD