[PAXtss]

To add another question:

Can you monitor all packs with one set of BMS that are tied with small wire jumpers into same level cells on other packs? Only 12 BMS ties but each connected to 3 cells.

For your question- you should have no problem with the charging - it will just take longer. I am planning on doing it with two halves of a Leaf for 180V. I just don't know how many BMS I will be using - 48 or 96- $600 difference.

 

[PAXtss]

Thanks Brian,
I can see where it could open issues if there was an imbalance in the two large packs.
Having each cell (actually two parallel cells) on its own BMS would be safer.

 

[PAXtss]

I feel like I hijacked this topic-
but- one last question - I looked at re-configuring the cells- these are gen 3 leaf - double modules and the cells are glued together and even though I think that I could separate them I fear doing damage as I have 24 doubles so I would have to separate 48 cells- scary

So each pack is is series with heavy cables at negative and positive terminals going to controller. I could connect all cells at same level with connecting wires- any size and thus parallel the cells on that level. The question is how much current could/would flow through these wires? It seems that due to same level of voltage there would be minimum but-- I did flunk out of engineering school and that was not EE.

 

[PAXtss]

Actually I was thinking about paralleling the whole cell or module. Not just the center tap which is positive for one cell and negative for the other. There would be three wires tothe first module - neg,center tap, positive and two to each following module (-,+,-,+,-,+,-,+) same as a BMS would do. so the cells on each level would be parallel from one pack to next while each pack is in series and parallel as a pack. The question is how much current flow from cell to cell under different circumstances - current draw of motor and a weak cell situation being two I can think of. The wires connecting the cells could be larger than regular BMS wires if needed. It seems feasible but electricity tends to trick my brain a bit. I thought that Tesla does something like this with fused wires in case a cell goes out.
I do know that the safe way is to just BMS all lower parallel cell - 96 in total-$600 more than 48 if l did the wires, it is just my cheap nature that I am looking at options.