depends on some factors.
mine is switched on 24/7 but i scheduled only to once a day rather than non stop.
mine requires 2 charges to complete the house.

in turn the battery will weaken in slightly over a year.
u'll notice it when either

1 - tasks perform requires more charges
2 - cant really return home
3 - indicator flashing (this one in dire need of battery change liao)

for me is usually option #1. the usual 2 charges to finish up my house, by year end it should take 3-4 charges.
my top 3 pics again

1 - https://www.neatorobotics.com/
2 - https://www.lazada.com.my/shop-vacuum-cleaners/xiaomi/
3 - https://www.irobot.com/For-the-Home/Vacuuming/Roomba
or subsequently u can head on over to retail to see it in action

corvan @ damansara utama. same row as 7-11/astro
u can find neato and roomba and even see it in action, real live demo over at corvan. yes it is more expensive cause its retail in damansara utama. but see only la, wanna buy just buy online. its cheaper.