Hey Dans! Sorry for not getting back to you sooner. I was actually unaware of this section but I am here to help. You probably solved this already but I would like to provide some insight. The amp rate would be based on manufactured recommended charge rates. Different brands recommend different rates. Higher performing packs can be charged at higher rates. In our case our batteries are designed for up to a 5C charge rate. for reference 1C is a 1 hour charge and is based on the actual amp hour of said battery. A 1000mah battery would be 1amp hour. 1C would be 1 amp. 5C would be 5 amps. For a 6700mah battery the amp hour would be 6.7 Amps. 1c would be 6.7 amps. 5c would be 33.5 amps. A 5 C charge rate should be about 20 minutes when balance charging.
I would recomend setting the time based on this and always give yourself some buffer room. Balancing can extend charge time so make sure you add a good 10-15 minutes on top of whatever you are expecting the charge time to be.
Hope this helps. If you have any other questions let me know. Or give us a call toll free at 888 654 4450.