BMW S-Box Voltage & Current Limits

[Marvin]

Does anyone know the voltage and current limits supported? I guess to be safe use max voltage of the hybrid pack but would be great to know if this coil be used for higher voltage applications as well. Thanks in advance.

[tom91]

I would not recommend using it above 400V, all the internals will designed around these limits. Voltage measurements and isolation in particular.

[Marvin]

Perfect thanks Tom

[mane2]

Related to current limits, 24kWh X5 G05 pack has 350A fuse and 12 modules. But I have not yet tested how much peak current and you can pull through that or for how long. In my other car I can pull over 1000A using 400A fuse for a few seconds, probably even longer (Tesla modules).

Those smaller packs (330, 530e, 745e etc) have smaller fuse and contactors rated for smaller currents. They have have less parallel cells so max current you can pull will be less anyway.

[tom91]

The contactors are what will limit the current, all busbars inside are relatively small and so are the connections on the box. Pushing any sort of current >100A for longer periods (over a few seconds) will cause issues I believe.