A while ago, I asked this question, which got marked as primarily opinion based.This is not an opinion-based question. This question is (clearly) asking why system RAM cannot have a battery backup in the same way as the CMOS and game-cartridges can.I have edited the question to make myself clear.Can it be reopened and answered ?

While there are some answers , there is a need for an answer that would include some math and tech about how ( modern ) RAM functions (refresh cycles, etc..) and quantity (number of NAND cells, etc..) and an analysis of the power requirement of a battery to keep them alive and comparison to common (non-laptop) battery capacities.