1.0a is fine and still low for a 2200mah. 1c is usually considered max charge rate for generic batteries which would be 2.2a for a 2200mah so even at your max 1.0a you're still charging it less than half of the min for safety. Recommend getting a charger thatll charge at 3a at least. Quality batteries can do 2x,5x some even 10c which on a 2000mah would be 20amp charge. I've charged my 2200mahs at 3a frequently even though they say 1c (2.2a)