Definite and indefinite noun after 找
Generally speaking, there isn't much of a direct, one-to-one mapping of phrases to English phrases with determiners, particularly when "the" is used in more general ways. Examples abound in constructions like The Flowers of Evil (恶之花) or "The Brothers Grimm" (格林兄弟). However, these have additional qualifiers "恶之" or "格林" that specify which flowers or which brothers we are talking about, so naturally we would use "the".

Let's look at an example without any qualifiers then:


  我今天去了便利店。


Since different convenience stores abound, I wouldn't expect the speaker to necessarily be referring to a specific one (particularly without the addition of 那) or alternatively, to any one (without 一间). I would assume "a convenience store" if the speaker was recounting his afternoon in another district, whereas I would assume "the convenience store" if the speaker was talking about walking around the block around his apartment. So context really matters.

Similarly, in the case with 找充電器, it's a bit unclear without context. At your home, I would expect 我找充电器 to indicate that you are looking for your phone charger (so "the charger"). At someone else's home or in say, a shopping mall or cafe, I might expect this more to mean "I'm looking for a charger." unless there is only one charger and you've misplaced it, because I'd be more likely to assume that you want to borrow a charger. In such a setting, I would expect something like "我的充电器" or "你借给的充电器" to indicate that you are looking for the charger.