Hello everybody,
I am working on my 14S9P Samsung 40T battery build and before starting to print the enclosure, I want to make sure that I’ve considered all important aspects to fit everything in that box.
Concerning the fusing, I’ve decided not to go with individual cell fuse wires/nickelstrips. Instead I want to use one or two typical car/midi fuses rated with 200A even though I am using a 300 A ANT BMS for charge and discharge limiting.
The question I have is where to place the fuses to ensure safe operation.
As I understand, the FETs in the BMS fail open in worst case and thus the current e.g. from the charger rushes into the cells. That’s why I would consider a fuse between the BMS and the battery negative busbar (not depicted yet in the drawing)
However, I’ve read somewhere else that fusing B+ would be enough since current flow will be interrupted anyways.
Others say, fusing is not beneficial because they cause trouble… I agree, if the chosen rating is inadequate. I personally see fuses as a last resort and if a molten 200 A fuse could prevent a total thermal runaway I would be happy enough.
Do you guys have other thoughts on that?
Any battery expert could also have a look on the wiring?