It is accessibility for repair and swapping batteries and the associated multitude of connectors that will need to be unhooked and reattached to a replacement. Thinking about repair and maintenance, that can worry me. replacing a battery is not as simple and, the whole pack will need to be replaced most of the time. There is a compromise between cost, ease of setup, maintenance, and compactness. Too compact and the whole thing will need to start coming apart to access the fault which is costly. I don’t see battery tech being less costly vs propane, they will about break even in the long run.

looking at the cost of a NMC battery, lithium just about matches or exceeds the cost of cobalt.(especially in 2022 where lithium was double its cost vs now) Cobalt is used less than lithium in the battery. I still think it is not the abundance of lithium but the cost of sourcing it from inefficient time consuming brine, or large mining operations that need to cover large areas as lithium is spread out. not to mention the environmental impact from mining it. After all battery production was supposed to help prevent more environmental concerns but sourcing it is just not great. global warming may be mitigated. Yet capturing CO2 is the most efficient at reducing environmental impact. Batteries are lower CO2 produced, but the impact of mining is nothing to scoff at.

looking at a cursory glance at wikipedia, li ion battery have lower energy density(KW/L) compared to Liquid propane. uncompressing propane will return it to a gas which is valuable because, the gas can more easily fired unlike gasoline where the liquid needs to be vaporized to turn a large volume into gas.(or coal where it needs to be pulverized) Natural gas power plants are far the easiest to retrofit a CO2 recycling system, by capturing, storing and using propane and switching to NG when propane runs out. Not to mention the charging time for batteries will always be larger than converting CO2 back to Propane.

I believe batteries should only be used for shorter term peak power demands. Propane storage from CO2 capturing is more likely to be accepted, easily transported to crisis areas that need longer time of power produced to rebuild necessary renewable or fixing the grid, and much better than batteries at reducing environmental impacts.