Blinky racing battery help

[adey]

Hi all. Been racing for many years with buggies and have tons of experience but I am struggling to understand an issue with blinky racing. We are thinking of running a buggy class with 13.5 blinky and some of the drivers have said with today's low profile lipos they would dump in the race. The batteries are ok with a 7.5 with boost but a 13.5 blinky would take up too much power and the battery would dump. Can anybody explain too me how a 7.5 with boost used less power than a 13.5 blinky. Many thanks.