When you say "running out of power" what do you mean? You can teach a bot to recharge other bots.
I've got a bot set to pick them up -> while hands empty, and wait; within a beacon. - after setting up a few beacons where people are, I set it to do that near a beacon. Then I trade with them; warping people across the map. Until the beacon area is empty, then move them to the next beacon, - all while staying at home; - And if he runs out of power i can send a recharge bot to that particular beacon fairly easily...
I feel like it's kind of an exploit to trade with bots across the map... But it gets tedious with the issues you mentioned :).