I use a cheap 12v 5A power supply
.
http://www.hobbypartz.com/acadfortht6c.html
I guess its 7.5A, but I dont care. Ive been using it with this charger for ever and its never had any issues! At least 100+ charges, discharges, etc
http://www.hobbypartz.com/60p-dyc-1004.html
I charge 2s, 3s, 4s up to 5 amps. Everything stays cool. For under $40 Im happy.