When I installed 19 gen 2 Nissan LEAF modules into my VX-1, I decided to not install BMS at that time. I bottom-balanced the cells as many have done, but I never wanted to keep it that way forever. Part of my long-term concern is that 2 of my 19 modules came from a different battery pack than the rest, so their capacity/use history doesn't match the others. While a BMS (especially one that communicates with both the charger and motor controller) would be preferable, I've decided to at least get one step closer toward better battery management.
My 19-module pack is 38S, so I purchased two 0.8A 20S "inductive active balance" boards from AliExpress (https://www.aliexpress.com/item/4000790255916.html) as identified by israndy (https://visforvoltage.org/comment/79837#comment-79837). Each board has 3 connectors with 7 wires each: [B-,1,2,3,4,5,6] [7,8,9,10,11,12,13] [14,15,16,17,18,19,20]. The AliExpress listing for these boards includes the following information: "Note (13 or more string plugs need to be inserted obliquely, first touch the B-pins and insert them obliquely upwards, otherwise it may cause the board to burn out)." I am interpreting that as the need to plug in the first connector with the B-, then the second connector [7-13], then the third connector [14-20]. Seems straightforward.
Now for the part where I'm not certain: how do I connect the two balance boards in series? I assume I want to overlap the balancers by a few cells so the cells on the ends don't bear the brunt of the balancing. Or maybe this isn't a thing, because they should all ultimately equalize over time. But should I put the first positive terminal of the second balancing board on the second-to-last cell positive of the cells covered by the first balancing board? Or should the last positive of the first board and the first positive of the second board be connected to the same cell? In my mind, the latter seems more risky. I should probably state that I can more easily wrap my head around (DC) electricity than electronics...
Part of my balancing board project will include installation of the orange plastic LEAF busbar covers with BMS wiring. I bought Sumitomo 32-pin (6098-5289) and 24-pin (6098-5285) connectors and 8230-5379 male terminal pins so I can more cleanly connect my balance boards. Full disclosure: the 24-pin connector may be the wrong part number; I will need to scrape away some plastic on either the male or female connector so the two will pair up. The pins appear to align otherwise.
This diagram is an example of how I imagine hooking everything up. If I'm way off base, I appreciate any assistance you can provide!