Hi Alisha,

If you are REALLY on a shoestring, and this is not a formal product, then breaking one of the Taiwanese cordless screwdrivers or drills yields useful goodies like a charger and battery combo. The Chargers are often crap, so it pays to have a good look and get a "fast charger", because its difficult to make a crap fast charger that won't destroy the battery within the warranty....

Steve

PS For such a good idea, I collect the motors and gearboxes for robotics projects........