Lithium fire protection

[nfbr]

So back to the original post concept. A metal box, with some fire resistant layer, 20L of water, and black poly hose. Overheat would quickly melt hose, dumping fresh water into box, cooling battery, and preventing spread.
Assuming this happens due to controller failure and overcharge whilst you are off the boat.
And assuming the the LiFePO4 actually fails, which it probably wont.

Seems like cheap simple insurance with almost no tech.

Worst case - fresh water on battery is likely not a strong conductor and of limited risk.

[Journeyman]

CharlieJ, interesting. However an all metal battery box gives me pause. Would hate to have the batteries tumble against the box on a roll over. If I went this route I guess I would need some welded in strong ties on the box floor (so the box dies not leak) to tie down the batteries?

[mickt243]

Originally Posted by Journeyman

CharlieJ, interesting. However an all metal battery box gives me pause. Would hate to have the batteries tumble against the box on a roll over. If I went this route I guess I would need some welded in strong ties on the box floor (so the box dies not leak) to tie down the batteries?

Doesn’t matter what kind of box or even no box, you *always* need them tied down well so they can’t fly about and destroy stuff in a knockdown or rollover....

[GordMay]

Originally Posted by mickt243

Doesn’t matter what kind of box or even no box, you *always* need them tied down well so they can’t fly about and destroy stuff in a knockdown or rollover....

Indeed.
ABYC recommends that the battery not move more than one inch in any direction, with a force equal to the weight of the battery.

[CFS Klopas]

In the US, batteries are also required by law to not move. They also must be designed to not allow terminals to come in contact with metal, a metal box would have to be carefully shielded.

https://www.law.cornell.edu/cfr/text/33/183.420

[Journeyman]

Of course all batteries need to be secured, my point is putting them in a metal box might pose special tie down challenges. I abhor the idea of anything metallic in the vicinity of my bank for fear of shorting the electrodes in violent weather.

[Delfin]

Originally Posted by Journeyman

Of course all batteries need to be secured, my point is putting them in a metal box might pose special tie down challenges. I abhor the idea of anything metallic in the vicinity of my bank for fear of shorting the electrodes in violent weather.

I built my battery box out of 3/4" glassed Marine ply, then had bed liner sprayed on the inside. Out would certainly hold water, but the least of my worries would be my LFP bank catching on fire. It is a very safe chemistry, arguably more so than LA.