Newb Asks: Why don't EVs use Breakers instead of Fuses?

[Gregski]

just got to thinking why don't OEM manufacturers use circuit breakers instead of fuses in the battery packs ie the contactor aka safety boxes? placement aside I know nobody would want to drop a battery pack and bust it open in order to flip a switch on the circuit breaker, but the same needs to be done to replace a blown fuse so that's a wash

below is a 350 amp fuse commonly found in the BMW 530e, 330e, and X5 models

and here are some circuit breakers, looking for pics I learned a lot of these are 3 pole but there's no reason why they couldn't offer them as a single pole

350a.jpg (4.58 KiB) Viewed 3182 times

OIP.jpg (2.72 KiB) Viewed 3182 times

[jrbe]

The breakers need to be rated for DC, that's where the costs start piling up.

Fuses are cheaper and usually smaller than breakers.

The all are sized for protecting the wire. If ît blows a few times something is very wrong and can have catastrophic to the inverter results when they go, so makes a resettable breaker kind of irrelevant at that point.
But sizing a fuse is an odd thing to try to do, it's not usually as straight forward as you'd think it should be.