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.

Humanas said:

My suggestion: allow the player wearing the armour to get constant "power readouts" so they know approximately how much time they have left. I would also remove the random factor. Armour is powered for 5 hours assuming light activity (walking, etc.). Combat and strenuous activity reduces this (maybe 1 round uses the equivalent of 10 minutes?) Good- or Exceptional quality armour might extend the battery life.

As you say, it's not worth the risk if you;re taking your life into your hands every time you don the armour.

Of course there is nothing stopping you from buying multiple batteries for your armour.  Or re-charging them from a suitable power source.  A generator, a Chimera APC, solar panels, a turbine engine fixed with a power coupling to recharge batteries, etc etc.  What is the rarity, weight, and cost of said power supply?  I just used a Heavy Charge pack, in the DH Core Book, and has a listed weight of 10% of the Weapon (in this case Armour ;)

 In our game we allowed to buy "military power supply" for about 2'000 thrones, that lasted for a week or so. 

My solution has been to ban power armours completely. My acolytes are not powerful inquisitors or spacemarines, they're squishy humans caught on the wrong side of very bad day.

For that reason I'm making it difficult for them to get any cool equipment (Bolters, powerswords, plasmas, etc.)

 Please. You dont have to ban it, because most acolytes wont be able to afford it. Maybe they will recieve it as a gift from their inquisitor, to fight a powerfull deamon. 

Avarage acolytes cries when he fires a bolter because 6 rounds from that are worth his monthly salary. 

Hummm. My Players probably will never be able to afford it, even if I'm paying them every 400exp (potentially by accident - the sidebar on pg29 of the core rules can be interpreted in two ways…)

Never liked the wealth system in this game. It seemed like a rather useless mechanic. We've just decided that players received a steady stipend from their Inquisitor as well as the occasional "equip yourselves" bonus.

Of course, anything the Acolytes are able to repossess is fair game.

the random factor comes from the fact that most Power Armor is "Vintage" by the time the players get it and activity level affects the power drain. unless you have a short in your power loop you will get about five hours of light activity. if your powerlifting and reenacting an Arnie movie expect it to last an hour.

also, unless the campaign IS an arnie movie, the power armors are far from being useful in the end, as they're not so stealthy.

1d5 hours is a cripplingly short amount of time, and it seems like such a letdown to spend all of that time, effort, and money finding such an expensive piece of military equipment only for it to run out of power in the middle of a firefight or an investigation. Adepta Sororitas power armor (which Blood of Martyrs Battle Sisters can start with at first level) never runs out of power unless the backpack power plant is disabled or damaged. In Black Crusade, power armor (and Terminator armor!) lasts for 24 hours instead of 1d5 before needing to be replaced or recharged, and that's assuming you didn't take the "sustainable power source" subsystem, which, again, makes it everlasting unless damaged. If you do insist on rationing your Acolytes' power armor time, I suggest using Rogue Trader's Heavy Power Armor as an example: Lasts for 12 hours, but requires 24 hours to fully recharge (essentially, an hour's charge equates to half an hour of combat activity). This lets them use their power armor on extended investigations but requires them to use it strategically, lest they run out of time to recharge their armor.

I feel the Macharian handbook does it best, offering a slew of power armors with all the different use times and then also offers upgrades (like a military grade power pack)

Other options:

1 hour heavy use, 5 hours light use + 1d3/1d5 if you want

Replaceable packs, another acolyte (a techie most often), can swap them out in X time

Extra batteries to increase the time, treat like an ammo backpack

Humanas said:

Remember that in 40Ks future no one in the empire really knows how any of this stuff works.