High capacity LiFePo4 and electrocution risk when flooding in case of capsize?

[Franziska]

Hi,

we have an 840Ah LiFePo4 battery on board.

While they are reasonably safe from thermal runaway we had a discussion recently of what would happen if the boat gets flooded by capsize or other.

Not so much in terms of fire hazard (we carry a bucket of sand as well as extinguishers and buckets, the latter come handy if there is no electricity to run a pump) but more regarding the risk of getting electricuted when swimming in the same soup after a capsize.
The battery is tied down well, but as it's mounted on the bridgedeck it would be submerged.

As a capsize could happen in an instance it would be hard to isolate it by hand fast enough and probably impossible anyway as the terminals would become submerged immediately.

Any thoughts on this by the experts?

[goboatingnow]

Firstly if it’s LFP , it’s not that they are “ reasonably “ safe from thermal runaway , they are completely safe as thermal runaway cannot happen. ( there can be thermal faults due to high currents , but not thermal runaway )

As to electrocution , electrically that’s essentially impossible simply by being in the same water. Any conduction occurring shorts both terminals and you are not in the conduction path