A seperatist crashes in the forrest of an uninhabited planet. Only the droids survive, after "the Last Mechanic" passes on. eventually blaster packs run out against hostile beasts...

Over time they develop a tribal culture. Tell me about it: ....

They're adorn themselves with capes and cloaks made from animal pelts and jewelry made from fangs, and wear animal skulls like helmets. They paint crude red and white markings on their bodies, mostly single stripes.

A tactical droid has become a chieftain-like figure, commanding the droid tribe from a throne made from the captain's chair decorated with bits and pieces of destroyed droids and animal pelts. He rules with an iron fist over its tribe, doing everything it can to stop their numbers from diminishing further as they are destroyed by wild animals, the forces of nature, and the ravages of time. He's not interested in leaving the planet, as he dimly remembers having to answer to a higher authority in his old existence. When outsiders arrive, he will negotiate for parts, power packs, and mechanical expertise in good faith, but the moment he think the outsiders will attract attention from the wider galaxy, he will turn on them and try to imprison them, to use them as mechanics (no matter if they lack all skill in that area).

He has an advisor/shaman protocol droid that has suffered a memory malfunction and can only speak in some guttural alien language no one but the tactical droid understands. Intricate patterns have been etched into his golden shell, and he has a crude red stripe painted vertically over his face. One of his photoreceptor eyes is missing and has been replaced with a gleaming precious stone.

Sounds really cool - but how would they recharge themselves?

From the crashed ship's reactor. A real-world nuclear submarine can deliver power for decades without refueling. Having a damaged starship reactor give enough power for the droids to recharge themselves doesn't seem like a stretch, and it's also serves as a lure to anyone scanning the area - that is, it serves as excuse for the PCs to find this spot.

4 hours ago, Azanael said:

Sounds really cool - but how would they recharge themselves?

From the crashed space ship. Or from the Static metal from the Myrkr trees and plants, or they are on a planet where they don``` t need too.. Do they really need to in this genre?
Extra battery packs?.. How long do they last without recharging? A lifetime or more?... Thing is, I think they are in need of a bit of repair and might appreciate if a mechanic drops by...

However, it` s Space Opera, it works if we want it to work...

2 hours ago, Azanael said:

Sounds really cool - but how would they recharge themselves?

I'd say a gonk power droid, which is a mini reactor on stubby legs, and they're feeding the gonk power droid with fuel from the non-operational ships reactor, whoever controls the gonk is the chief but there are a few independent droids that possess fusion lanterns.

2 hours ago, Azanael said:

Sounds really cool - but how would they recharge themselves?

Water wheels, naturally.

Or High-Efficiency Solar Panels made from downed TIEs.

A party locates the droids, drawn by the reactor picked up on their sensors. Interaction is complicated by the cybernetics utilized by the newcomers. The shaman communicates to the chieftain that the organics have taken trophies from droids in order to enhance themselves- abomination! Alternately, the droids view the cybernetics as the result of enterprising droids engaging in a parasitic relationship- perhaps to be emulated, consensual or otherwise.