Lost Phone, now doesn't turn on

[thesecretlieswithin]

A few months ago I lost a phone around the house. It was recently found (dry, no visible damage that wasn't there before), but when it was plugged in it failed to charge. I've left it to charge the entire day, but it still fails to turn on.
I suspect that the battery is dead. Would I be right in saying this?
I just want to get a second opinion before I order a replacement from ebay.

Thanks in advance for your time

 

[COLGeek]

It does sound like a completely discharged battery. That is what I would assume as well.