How long does it take an iPhone to recharge after it had been dead a long time?

My cousin just gave me her old iPhone 5. It's in good condition but it's been sitting in her drawer for months. I don't know how many months but a pretty long while. Anyways, i out it on the charger and it hasn't moved from the red. It's been on maybe… At least a half hour. Is it okay? I don't know anything about these machines lol.

Any Any iPhone 5 by now will have an older battery. Rechargeable batteries don't last forever, and on most phones by the end of a standard 2 year contract they're showing clear signs of not being able to last as long between recharges as they used to.

So even before your cousin stopped using her iPhone 5 the battery was well past its prime. But lithium rechargeable batteries used in all modern phones also suffer serious damage if they're left uncharged for long periods as the battery cell voltage falls too low to allow recharging.

If after a few hours there's no sign of any improvement then there's not going to be any. Whilst you try charging the phone, make sure it's on a hard flame-resistant surface and not left unattended as the battery is likely to get very hot whilst the charger tries to brute-force a charge into it and sometimes that can cause a fire.

You have two options: pay for a replacement battery, and that's a risk because the fault might not actually be the battery, or sell the phone for spares/repairs and use the cash towards buying a fully-functional phone.