Depends on what exactly we're talking about. Some low-tier cyberware, such as fashionware or booster/speedware, all function off a single battery installed somewhere in the body. However, cybernetic implants that are more power-heavy require batteries all to themselves, such as cyberarms, cyberlegs, cyberhands (if the hands are not attached to a cyberarm, that is), cyber-snakes, and linear frames (a single linear frame requires four batteries). These batteries can last for a full year, and cost roughly 100 eurodollars a piece (200 if you don't bring in the old batteries for recharging).

Source: Chromebook #3, pg. 120(Not exactly on 120, but the segment in which this information is given begins on 120).

Also, Full Body Conversions are powered by similar batteries, just more powerful ones, according to a comment from Mike Pondsmith which currently eludes me (I’ll edit the link to it in once I find it).

I’d like to mention, though, that I don’t know if any of this has changed by the time of 2077, since all of that lore was written for the 2020 tabletop games. While I don’t have any reason to suspect the technology has changed — since nothing in CP Red(which is set in 2045) not 2077 suggests as much — it’s entirely possible that other methods have been developed. But, until any canon lore source confirms that, I’ll stick to the battery explanation.

Hope this helps!