I'm with j-dub. I'd charge it at 1 amp. Should charge in less than hour (unless it's completely dead).

When you charge at very high amps, you'll get a faster charge and good short term performance, but the battery won't last as long on a full charge. Charge at low amps and obviously it'll take longer to charge, you'll get reduced short term performance, but the battery will last longer.

I've found that charging say a 1100 at 1.1 or a 3300 at 3.3 (etc) is a good balance.