Battery electrolysis of h2O into o2 and h2 that these engage in need a consistent power source. Either the power source is the core of the earth spinning, or there is some electrical something making these nodules consistently split.

I'll be curious about it, but I think that climate change may slow more from lower cost land surface batteries than these electrolysis water splitting batteries and associated ecosystems. Aka I won't hold my breath... ba dum tsss

If these things are oxygenating water in the ocean depths, maybe it's a bad idea to mine them.