Interesting, but will that protect the battery against overcurrent? If the inverter is bypassing the BMS, it will not be able to measure the load from the inverter and will not shut off right?
No, it won't. But the 280Ah is rated for 1C, thus 280A max. My inverter is 1500W, so approx 125A on full load, so well within the specs of the cells.
The BMS won't register/measure the inverter and its load, but I don't care. I have a Victron BMV installed, and the inverter does pass the shunt, so I'm still able to see the current draw from the cells.
Also, off course I did put a fuse on the cells, so in case of a short, the fuse will blow (I've installed a 150A block fuse, a Littlefuse CF8, which protects everything: Both inverter and the BMS, so if anything goes horribly wrong, I still have a final protection which will kick in.
Also, the fuse is rated much lower than the 1C cell rating, so the fuse will be gone long before the cells hits its maximum discharge current.
Even if I run everything at max, in the unlikely case i'm using the inverter at full load, AND pull >30A from the BMS at the same time. But even in that case, the fuse won't pop immediately, since all fuses can handle overcurrent for a certain amount of time. The higher the overcurrent, the shorter the time you can exceed its rating). But realisticly: Chances this will happen is like 0.01%
And if I want to do that for whatever reason, I still can upgrade my fuse to a 200A version, my wiring is 50mm2 so should be able to handle it, but I don't see any need to oversize the fuse.
I also can run the inverter from the BMS, but with 120A i can't run it on full load. Also, lots of people are reporting the BMS generating a nice amount of heat when running a high loads, which would have me to redesign the enclosure (it doesn't have much airflow). And generally people recommend to stay on the low side and not stressing the electronics to high loads, so it will last longer.
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