Tesla 24V Modules in parallel

[jacky4566]

Looking to create a 2x2 power bank with Telsa 24V modules. 2 series by 2 parallel. Each module is 74p6s so that gives me a total of 148p12s.
48V system will be powering a 20kW (peak) BLDC motor and a variety of accessories.
I want to use these cells for their compact and weight savings compared to LifePO4.
Orion BMS JR. 2 was my planned BMS with the proper disconnects and such.

MY question is this.
Reading through Orion Documentation i found this article. Using the Orion BMS with Tesla Battery Modules

At the end of that document they REALLY do not advise paralleling the modules for reasons unexplained... Can anyone here elaborate on why?
If I parallels the cell taps with a 10 ohm resistor before connecting how is this any more dangerous that the rest of the cells in the pack?
My alternate option is buying 2 Orion BMS and treating them as separate packs only connected at the outputs. bonus here is redundant BMS should I need to field rig something.

Thoughts?

 

[eXodus]

Pretty simple, the pack voltages might the same - but the individual cells are not.

there might balanced packs - but not necessary cells between packs. So one pack you got cell 1 might be a charging at a different rate then cell 1 of pack 2. Depending how large the difference is - the balance wire might just melt down.

In general for each parallel string you should have a separate BMS.

What inverter are you going to use? I read that some people actually used 3 Tesla Model S modules in series for a "48V" system - since they are actually 22V module .

 

[jacky4566]

AH ok I understand now. Guess I just had to get someone to spell it out for me.

So if one set of cells has a slightly lower capacity, significant current COULD flow through the balance lead to the other set.

 

[eXodus]

So if one set of cells has a slightly lower capacity, significant current COULD flow through the balance lead to the other set.

Yep, that's why people are using Busbars in DIY batteries between the same parallel cells. - the current could be very high.