i made the battery charger from the beam online page and was wondering what volt output for the wall transformer do i need? (site below)

i have a variable one that has 3,4.5,6,9,12,15 volts.
and its variable amperage from either 100ma or 300ma.

http://beam-online.com/Robots/pcb/pages/charger.html

 

It depends on what battery voltage you would like to charge but you may want to put a series resistor in it so as to reduce the current out.