Still not 100% sure what your concern is.
I have two batteries. Each have an XT60 connector (lets call then OX1 and OX2) and a balanced charge connector (lets call them OBC1 and OBC2).
The two batteries will plug into a BMS system that will have two XT60 connectors and two balanced charge connectors (IX1, IX2, IBC1 and IBC2).
Everything will work perfectly if I make the following connections:
- OX1<->IX1
- OX2<->IX2
- OBC1 <->IBC1
- OBC2 <->IBC2
But what will happen if I accidentally connect the plugs like this (differences in red):
- OX1<->IX1
- OX2<->IX2
- OBC1 <-> IBC2
- OBC2 <-> IBC1
I predict bad stuff! Because you will ultimately be shorting the two 5S batteries together. Which maybe the polyfuses will protect me against?
Those polyfuse are going to be hell to solder on to wires and get them to stay in place. If you are going to do it, use through-hole poly fuses.
I've designed a PCB. Attached photo.