Depends on the ‘P’ of your pack. The lower the current you charge with the better. Generally you don’t want to exceed 1C charging, but you should be able to handle 2C max. A 4A charging charging a 4P battery charges each cell at 1A which is about .5C for 18650 cells. 4A charging should be good for the life of the pack assuming you’re running a 4p pack. You can do the math to find out charging rates for other setups.