Had to look back at one of my old posts for the current reading while burning wire... (the meter is a slow average) and the current measurement lags the power calculation for some insane reason on the meter. Notice the volt drop..
"Resting voltage was 47.23V so at 325A and 45.48V on the same meter that gives a battery to busbar resistance of 5.08 milli Ohm. "
https://secondlifestorage.com/showthread.php?tid=5027&page=8
Balancing act, but mainly wiring should be over rated (to cope with breaker trip rating delay) and high amp single pole breakers avoided if possible.
Running breakers close to long term use can create issues with heating and cooling cycles that loosen the connections but also means the fault issue is a little more comfortable. Bigger (over sized) cables can also carry more heat away from the breakers, which also impacts the breaker timing on thermal trip overload.
My packs have 100A breakers and I have effectively 9 packs (2 in series) connected to a busbar which is effectively then "protected" at 900A. BUT in reality those breakers would never trip in a fault and it would be molten aluminium or wires elsewhere that would be the "fuse". I am contemplating de-rating / swaping those breakers to 40A (on the to do list - when it get's high enough up in the list !).
When I was doing the research for the inverter build I ended up at a conclusion that something like 1x breaker + (1.2x to 1.5x) fuse in series was required for best protection. The fuse at the 2x-4x over current would blow fatser than the breaker. The breaker would service overloads and full on disaster situations. Marginal overloading the breakers would trip on (inverter overheating protection).
My thoughts / conclusions (all open to being shot down in flames as long as they are not caused by a battery fire) :
1. Fuses burn faster than breakers trip
2. FET's in an inverter can burn much faster than breakers trip
3. Fuses have a better chance at saving the FET's in a high amp rated inverter than a breaker
4. Small amp breakers over fuses for distribution (cheaper in long run and allows for switching)
5. Test and know for yourself what works and what does not work in reality
6. Don't always go for a single big cable, 2 cables of the same overall conductor csa can cary more amps (see litz wire principle)
7. Multipole breakers (lower amp per pole) are more reliable/safer than a single higher amp breaker
8. Still learning
And this is more "normal" for a peak (sustained) on the inverter that should be expected not to cause issues
Oh, in relation to the batter to busbar resistance of 5.08 milli Ohm :
47V battery with short on busbar would be 9250 Amps or... 434kW... and that scares the s**t out of me.