Classic/Antique Car Repair: dead battery

Question
I have a 1955 ford f100 with a 390/450hp engine. problem is that battery drains after driving one day. nothing is left on. it is a new red top optima battery. person I purchased truck from says that I need to keep a trickle charge on it. why?

Answer
Your charging system is not working.  Get it checked.  Trickle charges are not for everyday use.  That is crazy.  You probably need a new alternator.  Have Pep Boys or someone like that check it and you can put it on yourself.  Just unbolt and bolt the new one on.  
There is also the chance that the batt is bad.  jack