Burnt/melted battery wire, do I need to replace it right away?

Man, definitely replace it right away. Burned or melted wire is serious stuff - it can cause a short, damage the equipment, or even start a fire. I've dealt with that before with a client who ignored it and the whole panel went bad.

I'd say it depends on how badly it burned, you know? if it's just the tip of the wire or if it melted completely, that's a whole different situation. the thing is, a burned wire usually means there was a short or an overload, so before you go replacing it you gotta understand what caused it. i always find it suspicious when something just burns out of nowhere, like... was it really the wire or was it the charger? did the phone get too hot? i'd recommend you take some time to investigate because if you replace the wire and the problem keeps happening, you'll have wasted money.

now, if you really need to use the device urgently, then yeah, you can replace it. but let me tell you: it's not recommended to use it with a damaged wire because not only does it not charge properly (or doesn't charge at all) but it also poses a risk of a more serious short. i've seen people fry their phone's connector because of that. if you're gonna replace it, get an original wire or good quality one, not that super cheap stuff. i get that when you're in a pinch you wanna spend less, but those cheap wires just make everything worse.

my honest suggestion: take a photo of the burned wire, check the charger too, and if everything else is fine, then yeah you replace it. but do it without rushing so you can figure out if it's not some other component that's acting up. i know plenty of people who replaced the wire thinking that was it and found out later it was the charger that was actually broken.