Wireless Smoke/heat alarms with 10 year sealed battery

Speaking with building control, they want mains wired interlinked smoke alarms to upper and ground floor, which i agree with, but... why cant we now install the 10 year sealed battery RF units?

As a sensor unit has a life span of 10 years and should be replaced at this point, what is the reason for not allowing the battery ones? Do the regs need updating to allow these units?