Prius 2001 battery fire

Certainly possible, although if the battery sealing service had never been performed I'm not sure why anyone would have had the case open. I didn't think they generally did that.

 

This photo taken from the rear of the car, the seat back is behind it, shows the split in the traction battery routes to the control electronics where a safety relay is normally open:

However, you'll notice the high voltage of each bank is brought into the close space of the control electronics. All it would take would be curious millipede or garter snake to become a fusible link and 'strike an arc.'

My Graham scanner reports traction battery current and I've seen ~50 A charge and ~70 A discharge. The internal resistance of these batteries is impressively low:

In this case, descending a hill with momentary braking to avoid overspeed, several spikes to around 55 A.

Bob Wilson

 

The photo of the opened battery shows the cables from the rear of modules 19 and 20 to the service-plug/safety-fuse assembly. That's normally closed; open only when the service plug is manually pulled or the fuse blows. I would love to know the condition of the fuse in the burned vehicle; one of those photos showed the service plug removed, but someone probably pulled it after the fire.

The cables that lead to the system main relay attach to the front terminals of modules 1 and 38, not visible in this photo from the rear. The SMR is normally open, closed only after the key's been turned to 'start' and in READY mode.

Also removed in the opened-battery photo are the busbar protectors. You can see the busbars and terminal nuts in the photo, which you would not see with the long plastic busbar covers snapped on. The protective cover over the service-plug connections (modules 19 and 20) has been folded down out of the way, and is visible below where the cables attach.

I still can't make the burned hole in the first fire photo be near the electronics - it just doesn't look like a photo from the rear seat space looking into the trunk, which is what it would have to be to put the hole at the electronics end. And the vent duct on the electronics end attaches at the top of the battery case.

-Chap