Build this 1HP (745.6 Watts) Timer.  Plans $2.00. 
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I designed this device to time the operation of the 120V AC battery charger for my battery powered drill.  I found out the hard way that the battery chargers for these batteries run HOT.  If left plugged in all the time, they will burn out.  These type chargers run $40.00 to $70.00.  Yes, it is true that this charger will cost $30.00 to $40.00, But, it will not burn out.  The timer is a spring wound timer.  The timer is basically a switch that will stay on for the time set.  This switch (timer) will carry an electrical load up to 1HP (745.6 Watts).  I have never had a timer go bad, but if it did you can replace it for $20.00 or less.  The battery charger for my 19V craftsman drill draws 65 watts.  This document contains a bill of materials and step by step instructions with pictures that show how to build the timer box.  This will come to you by e-mail in the form of a 11 page PDF file.
I will give you any help that you need, also by e-mail.