Juan....its better to use a higher amp discharge then a lower amp one. 20 amps is about as low as you want to go really 30 or 35 amps is best. Integy sells a nice little reactor 30 which will discharge a pack at 30 amps and cut off at 5.4v per cell....I think they sell for 35 or 40 dollars. They are stand alone products so you dont need a power supply for them or anything. If your looking for a charger get what you can afford. The Pit Bull3x is what I would recomend.....that new Orion charger looks good but I have yet to see one or try one....I might pick one up over the summer to see how it works.