Even if your battery might work now there is no guarantee that it will not expand or explode later. Believe me i've seen a battery expand *after some* charging cycles *after* reviving it in a similar way (Nexus 4). In this case it "only" broke the display by expanding but i don't want to know what else could have happened.

If your phone doesn't want to charge your battery anymore it is probably for a good reason. Especially if it's been dead for so long.