Multi layer perovskites could make them worth carrying on ships that have to stop (canals and similar). If your batteries have to do 2400 out of 2500km and the

Multi layer perovskites could make them worth carrying on ships that have to stop (canals and similar). If your batteries have to do 2400 out of 2500km and then 2100km out of 2500km in two stretches that's a 10% reduction in battery cost (and a cargo increase). Even at 6% (high but achievable efficiency in the mid term) it's still worth slapping them on if it doesn't interfere with operation too much as they weigh comparatively nothing.