system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: I've heard that leaving wall/phone chargers pluged in when not charging wastes power. What prevents them from shutting off automatically when not charging a device?
gpt
When it comes to vampire power drains, phone chargers are a ridiculously small part of the puzzle.  There are plenty of appliances that do much more damage to your wallet.  Big electronics that enter a 'standby' mode are a huge draw.... TV, cable boxes, dvd player, computers, microwaves.  The thing about wall charger in particular is the AC->DC circuitry is always creating a complete circuit, whether you have something plugged into it or not, so, they're always drawing power.

There's a wide swing in terms of claims of how much unplugging the wall wart entirely will save, some say its negligible, some say its upwards of $50/yr.  Its worse to actually leave your phone plugged in all day, especially if its on.  If the phone is off its not as bad, and if nothing is connected its typically negligible...but, then people couldn't write click-bait articles about it!