I charged my NIMH battery last night for 3 hours. Went to bed, got up in the morning to fly the plane and the battery has no charge?

Is there like a 5 minute span you have to use the batteries? Seriously, nothing would work. Here i am charging it again for another 3 hours. This can't be right?

Thought i'd ask here. Want to know the truth before i go and get frustrated and its normal.

I mean, i use rechargable battereies for my RC cars and can use/run them for days. this makes no sense.