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I'm considering connecting a bank of four parallel 200ah 12v Victron Lithium Smart batteries using the Lynx Distributor to a Lynx BMS, similar to this schematic w/ two parallel and also similar to the diagram from the Lynx Distributor manual (page 10).
How did you compute the short circuit current through the fuse? You showed no math.
I don't think it's officially published. But we can arrive at a ballpark. I believe the 12v lifepo4 has four cells. Each lifepo4 cell has about 0.1mΩ of resistance. The resistance may vary a little based on the SOC. So let's assume 0.4mΩ per battery.
12v / 0.0004Ω = 30000A
I guess you are thinking about the arc quenching. Yes there is fusing with higher arc quenching. NH fuses for example.
On the other hand you are working with 12v and with lithium and the bank is not massive.
A few points about bms control, they have short circuit protection so will likely switch off in the event. But in the short duration there is a short the fuse blows and protection for the wiring happens so nothing shoud get hot. Torque everything to spec it will be fine.
I found these two very helpful resources:
- Nigel Calder speaking about AIC Ratings. Recommends a Class T fuse for LifePO4 installations: https://www.youtube.com/watch?v=CrwT52ehymQ
- Marine How To - Battery Banks & Over-Current Protection: https://marinehowto.com/battery-banks-over-current-protection/
The direction I am leaning towards will have MRBF fuses on each positive terminal, each leading to a Lynx Power-In, then a Class T Fuse after the Lynx BMS.
