So, according to the core rulebook pg 144 "…a standard non-military power supply lasts for 1d5 hours…"
This sounds kinda silly to me. Like, I am gonna wear this power armour and lets hope it's battery wont die in the middle of battle. For the Emperor!!
I understand that, this is the non-military power supply, but acolytes may don't have the necessary resources to outfit a power armour with a military power supply, witch in my guess works like the sororitas power armour.