Do you know what your bird weighs?The discharge rate on the multistar 4000 3s is only 10C, but does have a higher value for short period (20C for 10secs?). However, I notice if you weigh down the phantom (gimbal, flytrex, FPV, PMU, mini-IOSD, etc.) these batteries do not perform as well as stock phantom 2200mah ones in terms of movement. In my case, the phantom has a hard time keeping level with the load and 9443 props. I suspect it will manage much better with 9450 props, but haven't tried yet. It does not have a problem with the stock 2200mah battery, albeit does not last as long.